1267 lines
		
	
	
		
			56 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
			
		
		
	
	
			1267 lines
		
	
	
		
			56 KiB
		
	
	
	
		
			C
		
	
	
		
			Executable File
		
	
	
	
	
| /*
 | |
| ** 2001 September 15
 | |
| **
 | |
| ** The author disclaims copyright to this source code.  In place of
 | |
| ** a legal notice, here is a blessing:
 | |
| **
 | |
| **    May you do good and not evil.
 | |
| **    May you find forgiveness for yourself and forgive others.
 | |
| **    May you share freely, never taking more than you give.
 | |
| **
 | |
| *************************************************************************
 | |
| ** Internal interface definitions for SQLite.
 | |
| **
 | |
| ** @(#) $Id: sqliteInt.h,v 1.1.1.1 2004-03-11 22:22:22 alex Exp $
 | |
| */
 | |
| #include "config.h"
 | |
| #include "sqlite.h"
 | |
| #include "hash.h"
 | |
| #include "parse.h"
 | |
| #include "btree.h"
 | |
| #include <stdio.h>
 | |
| #include <stdlib.h>
 | |
| #include <string.h>
 | |
| #include <assert.h>
 | |
| 
 | |
| /*
 | |
| ** The maximum number of in-memory pages to use for the main database
 | |
| ** table and for temporary tables.
 | |
| */
 | |
| #define MAX_PAGES   2000
 | |
| #define TEMP_PAGES   500
 | |
| 
 | |
| /*
 | |
| ** If the following macro is set to 1, then NULL values are considered
 | |
| ** distinct for the SELECT DISTINCT statement and for UNION or EXCEPT
 | |
| ** compound queries.  No other SQL database engine (among those tested) 
 | |
| ** works this way except for OCELOT.  But the SQL92 spec implies that
 | |
| ** this is how things should work.
 | |
| **
 | |
| ** If the following macro is set to 0, then NULLs are indistinct for
 | |
| ** SELECT DISTINCT and for UNION.
 | |
| */
 | |
| #define NULL_ALWAYS_DISTINCT 0
 | |
| 
 | |
| /*
 | |
| ** If the following macro is set to 1, then NULL values are considered
 | |
| ** distinct when determining whether or not two entries are the same
 | |
| ** in a UNIQUE index.  This is the way PostgreSQL, Oracle, DB2, MySQL,
 | |
| ** OCELOT, and Firebird all work.  The SQL92 spec explicitly says this
 | |
| ** is the way things are suppose to work.
 | |
| **
 | |
| ** If the following macro is set to 0, the NULLs are indistinct for
 | |
| ** a UNIQUE index.  In this mode, you can only have a single NULL entry
 | |
| ** for a column declared UNIQUE.  This is the way Informix and SQL Server
 | |
| ** work.
 | |
| */
 | |
| #define NULL_DISTINCT_FOR_UNIQUE 1
 | |
| 
 | |
| /*
 | |
| ** The maximum number of attached databases.  This must be at least 2
 | |
| ** in order to support the main database file (0) and the file used to
 | |
| ** hold temporary tables (1).  And it must be less than 256 because
 | |
| ** an unsigned character is used to stored the database index.
 | |
| */
 | |
| #define MAX_ATTACHED 10
 | |
| 
 | |
| /*
 | |
| ** The next macro is used to determine where TEMP tables and indices
 | |
| ** are stored.  Possible values:
 | |
| **
 | |
| **   0    Always use a temporary files
 | |
| **   1    Use a file unless overridden by "PRAGMA temp_store"
 | |
| **   2    Use memory unless overridden by "PRAGMA temp_store"
 | |
| **   3    Always use memory
 | |
| */
 | |
| #ifndef TEMP_STORE
 | |
| # define TEMP_STORE 1
 | |
| #endif
 | |
| 
 | |
| /*
 | |
| ** When building SQLite for embedded systems where memory is scarce,
 | |
| ** you can define one or more of the following macros to omit extra
 | |
| ** features of the library and thus keep the size of the library to
 | |
| ** a minimum.
 | |
| */
 | |
| /* #define SQLITE_OMIT_AUTHORIZATION  1 */
 | |
| /* #define SQLITE_OMIT_INMEMORYDB     1 */
 | |
| /* #define SQLITE_OMIT_VACUUM         1 */
 | |
| /* #define SQLITE_OMIT_DATETIME_FUNCS 1 */
 | |
| /* #define SQLITE_OMIT_PROGRESS_CALLBACK 1 */
 | |
| 
 | |
| /*
 | |
| ** Integers of known sizes.  These typedefs might change for architectures
 | |
| ** where the sizes very.  Preprocessor macros are available so that the
 | |
| ** types can be conveniently redefined at compile-type.  Like this:
 | |
| **
 | |
| **         cc '-DUINTPTR_TYPE=long long int' ...
 | |
| */
 | |
| #ifndef UINT32_TYPE
 | |
| # define UINT32_TYPE unsigned int
 | |
| #endif
 | |
| #ifndef UINT16_TYPE
 | |
| # define UINT16_TYPE unsigned short int
 | |
| #endif
 | |
| #ifndef UINT8_TYPE
 | |
| # define UINT8_TYPE unsigned char
 | |
| #endif
 | |
| #ifndef INT8_TYPE
 | |
| # define INT8_TYPE signed char
 | |
| #endif
 | |
| #ifndef INTPTR_TYPE
 | |
| # if SQLITE_PTR_SZ==4
 | |
| #   define INTPTR_TYPE int
 | |
| # else
 | |
| #   define INTPTR_TYPE long long
 | |
| # endif
 | |
| #endif
 | |
| typedef UINT32_TYPE u32;           /* 4-byte unsigned integer */
 | |
| typedef UINT16_TYPE u16;           /* 2-byte unsigned integer */
 | |
| typedef UINT8_TYPE u8;             /* 1-byte unsigned integer */
 | |
| typedef UINT8_TYPE i8;             /* 1-byte signed integer */
 | |
| typedef INTPTR_TYPE ptr;           /* Big enough to hold a pointer */
 | |
| typedef unsigned INTPTR_TYPE uptr; /* Big enough to hold a pointer */
 | |
| 
 | |
| /*
 | |
| ** Defer sourcing vdbe.h until after the "u8" typedef is defined.
 | |
| */
 | |
| #include "vdbe.h"
 | |
| 
 | |
| /*
 | |
| ** Most C compilers these days recognize "long double", don't they?
 | |
| ** Just in case we encounter one that does not, we will create a macro
 | |
| ** for long double so that it can be easily changed to just "double".
 | |
| */
 | |
| #ifndef LONGDOUBLE_TYPE
 | |
| # define LONGDOUBLE_TYPE long double
 | |
| #endif
 | |
| 
 | |
| /*
 | |
| ** This macro casts a pointer to an integer.  Useful for doing
 | |
| ** pointer arithmetic.
 | |
| */
 | |
| #define Addr(X)  ((uptr)X)
 | |
| 
 | |
| /*
 | |
| ** The maximum number of bytes of data that can be put into a single
 | |
| ** row of a single table.  The upper bound on this limit is 16777215
 | |
| ** bytes (or 16MB-1).  We have arbitrarily set the limit to just 1MB
 | |
| ** here because the overflow page chain is inefficient for really big
 | |
| ** records and we want to discourage people from thinking that 
 | |
| ** multi-megabyte records are OK.  If your needs are different, you can
 | |
| ** change this define and recompile to increase or decrease the record
 | |
| ** size.
 | |
| **
 | |
| ** The 16777198 is computed as follows:  238 bytes of payload on the
 | |
| ** original pages plus 16448 overflow pages each holding 1020 bytes of
 | |
| ** data.
 | |
| */
 | |
| #define MAX_BYTES_PER_ROW  1048576
 | |
| /* #define MAX_BYTES_PER_ROW 16777198 */
 | |
| 
 | |
| /*
 | |
| ** If memory allocation problems are found, recompile with
 | |
| **
 | |
| **      -DMEMORY_DEBUG=1
 | |
| **
 | |
| ** to enable some sanity checking on malloc() and free().  To
 | |
| ** check for memory leaks, recompile with
 | |
| **
 | |
| **      -DMEMORY_DEBUG=2
 | |
| **
 | |
| ** and a line of text will be written to standard error for
 | |
| ** each malloc() and free().  This output can be analyzed
 | |
| ** by an AWK script to determine if there are any leaks.
 | |
| */
 | |
| #ifdef MEMORY_DEBUG
 | |
| # define sqliteMalloc(X)    sqliteMalloc_(X,1,__FILE__,__LINE__)
 | |
| # define sqliteMallocRaw(X) sqliteMalloc_(X,0,__FILE__,__LINE__)
 | |
| # define sqliteFree(X)      sqliteFree_(X,__FILE__,__LINE__)
 | |
| # define sqliteRealloc(X,Y) sqliteRealloc_(X,Y,__FILE__,__LINE__)
 | |
| # define sqliteStrDup(X)    sqliteStrDup_(X,__FILE__,__LINE__)
 | |
| # define sqliteStrNDup(X,Y) sqliteStrNDup_(X,Y,__FILE__,__LINE__)
 | |
|   void sqliteStrRealloc(char**);
 | |
| #else
 | |
| # define sqliteRealloc_(X,Y) sqliteRealloc(X,Y)
 | |
| # define sqliteStrRealloc(X)
 | |
| #endif
 | |
| 
 | |
| /*
 | |
| ** This variable gets set if malloc() ever fails.  After it gets set,
 | |
| ** the SQLite library shuts down permanently.
 | |
| */
 | |
| extern int sqlite_malloc_failed;
 | |
| 
 | |
| /*
 | |
| ** The following global variables are used for testing and debugging
 | |
| ** only.  They only work if MEMORY_DEBUG is defined.
 | |
| */
 | |
| #ifdef MEMORY_DEBUG
 | |
| extern int sqlite_nMalloc;       /* Number of sqliteMalloc() calls */
 | |
| extern int sqlite_nFree;         /* Number of sqliteFree() calls */
 | |
| extern int sqlite_iMallocFail;   /* Fail sqliteMalloc() after this many calls */
 | |
| #endif
 | |
| 
 | |
| /*
 | |
| ** Name of the master database table.  The master database table
 | |
| ** is a special table that holds the names and attributes of all
 | |
| ** user tables and indices.
 | |
| */
 | |
| #define MASTER_NAME       "sqlite_master"
 | |
| #define TEMP_MASTER_NAME  "sqlite_temp_master"
 | |
| 
 | |
| /*
 | |
| ** The name of the schema table.
 | |
| */
 | |
| #define SCHEMA_TABLE(x)  (x?TEMP_MASTER_NAME:MASTER_NAME)
 | |
| 
 | |
| /*
 | |
| ** A convenience macro that returns the number of elements in
 | |
| ** an array.
 | |
| */
 | |
| #define ArraySize(X)    (sizeof(X)/sizeof(X[0]))
 | |
| 
 | |
| /*
 | |
| ** Forward references to structures
 | |
| */
 | |
| typedef struct Column Column;
 | |
| typedef struct Table Table;
 | |
| typedef struct Index Index;
 | |
| typedef struct Instruction Instruction;
 | |
| typedef struct Expr Expr;
 | |
| typedef struct ExprList ExprList;
 | |
| typedef struct Parse Parse;
 | |
| typedef struct Token Token;
 | |
| typedef struct IdList IdList;
 | |
| typedef struct SrcList SrcList;
 | |
| typedef struct WhereInfo WhereInfo;
 | |
| typedef struct WhereLevel WhereLevel;
 | |
| typedef struct Select Select;
 | |
| typedef struct AggExpr AggExpr;
 | |
| typedef struct FuncDef FuncDef;
 | |
| typedef struct Trigger Trigger;
 | |
| typedef struct TriggerStep TriggerStep;
 | |
| typedef struct TriggerStack TriggerStack;
 | |
| typedef struct FKey FKey;
 | |
| typedef struct Db Db;
 | |
| typedef struct AuthContext AuthContext;
 | |
| 
 | |
| /*
 | |
| ** Each database file to be accessed by the system is an instance
 | |
| ** of the following structure.  There are normally two of these structures
 | |
| ** in the sqlite.aDb[] array.  aDb[0] is the main database file and
 | |
| ** aDb[1] is the database file used to hold temporary tables.  Additional
 | |
| ** databases may be attached.
 | |
| */
 | |
| struct Db {
 | |
|   char *zName;         /* Name of this database */
 | |
|   Btree *pBt;          /* The B*Tree structure for this database file */
 | |
|   int schema_cookie;   /* Database schema version number for this file */
 | |
|   Hash tblHash;        /* All tables indexed by name */
 | |
|   Hash idxHash;        /* All (named) indices indexed by name */
 | |
|   Hash trigHash;       /* All triggers indexed by name */
 | |
|   Hash aFKey;          /* Foreign keys indexed by to-table */
 | |
|   u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
 | |
|   u16 flags;           /* Flags associated with this database */
 | |
|   void *pAux;          /* Auxiliary data.  Usually NULL */
 | |
|   void (*xFreeAux)(void*);  /* Routine to free pAux */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** These macros can be used to test, set, or clear bits in the 
 | |
| ** Db.flags field.
 | |
| */
 | |
| #define DbHasProperty(D,I,P)     (((D)->aDb[I].flags&(P))==(P))
 | |
| #define DbHasAnyProperty(D,I,P)  (((D)->aDb[I].flags&(P))!=0)
 | |
| #define DbSetProperty(D,I,P)     (D)->aDb[I].flags|=(P)
 | |
| #define DbClearProperty(D,I,P)   (D)->aDb[I].flags&=~(P)
 | |
| 
 | |
| /*
 | |
| ** Allowed values for the DB.flags field.
 | |
| **
 | |
| ** The DB_Locked flag is set when the first OP_Transaction or OP_Checkpoint
 | |
| ** opcode is emitted for a database.  This prevents multiple occurances
 | |
| ** of those opcodes for the same database in the same program.  Similarly,
 | |
| ** the DB_Cookie flag is set when the OP_VerifyCookie opcode is emitted,
 | |
| ** and prevents duplicate OP_VerifyCookies from taking up space and slowing
 | |
| ** down execution.
 | |
| **
 | |
| ** The DB_SchemaLoaded flag is set after the database schema has been
 | |
| ** read into internal hash tables.
 | |
| **
 | |
| ** DB_UnresetViews means that one or more views have column names that
 | |
| ** have been filled out.  If the schema changes, these column names might
 | |
| ** changes and so the view will need to be reset.
 | |
| */
 | |
| #define DB_Locked          0x0001  /* OP_Transaction opcode has been emitted */
 | |
| #define DB_Cookie          0x0002  /* OP_VerifyCookie opcode has been emiited */
 | |
| #define DB_SchemaLoaded    0x0004  /* The schema has been loaded */
 | |
| #define DB_UnresetViews    0x0008  /* Some views have defined column names */
 | |
| 
 | |
| 
 | |
| /*
 | |
| ** Each database is an instance of the following structure.
 | |
| **
 | |
| ** The sqlite.file_format is initialized by the database file
 | |
| ** and helps determines how the data in the database file is
 | |
| ** represented.  This field allows newer versions of the library
 | |
| ** to read and write older databases.  The various file formats
 | |
| ** are as follows:
 | |
| **
 | |
| **     file_format==1    Version 2.1.0.
 | |
| **     file_format==2    Version 2.2.0. Add support for INTEGER PRIMARY KEY.
 | |
| **     file_format==3    Version 2.6.0. Fix empty-string index bug.
 | |
| **     file_format==4    Version 2.7.0. Add support for separate numeric and
 | |
| **                       text datatypes.
 | |
| **
 | |
| ** The sqlite.temp_store determines where temporary database files
 | |
| ** are stored.  If 1, then a file is created to hold those tables.  If
 | |
| ** 2, then they are held in memory.  0 means use the default value in
 | |
| ** the TEMP_STORE macro.
 | |
| **
 | |
| ** The sqlite.lastRowid records the last insert rowid generated by an
 | |
| ** insert statement.  Inserts on views do not affect its value.  Each
 | |
| ** trigger has its own context, so that lastRowid can be updated inside
 | |
| ** triggers as usual.  The previous value will be restored once the trigger
 | |
| ** exits.  Upon entering a before or instead of trigger, lastRowid is no
 | |
| ** longer (since after version 2.8.12) reset to -1.
 | |
| **
 | |
| ** The sqlite.nChange does not count changes within triggers and keeps no
 | |
| ** context.  It is reset at start of sqlite_exec.
 | |
| ** The sqlite.lsChange represents the number of changes made by the last
 | |
| ** insert, update, or delete statement.  It remains constant throughout the
 | |
| ** length of a statement and is then updated by OP_SetCounts.  It keeps a
 | |
| ** context stack just like lastRowid so that the count of changes
 | |
| ** within a trigger is not seen outside the trigger.  Changes to views do not
 | |
| ** affect the value of lsChange.
 | |
| ** The sqlite.csChange keeps track of the number of current changes (since
 | |
| ** the last statement) and is used to update sqlite_lsChange.
 | |
| */
 | |
| struct sqlite {
 | |
|   int nDb;                      /* Number of backends currently in use */
 | |
|   Db *aDb;                      /* All backends */
 | |
|   Db aDbStatic[2];              /* Static space for the 2 default backends */
 | |
|   int flags;                    /* Miscellanous flags. See below */
 | |
|   u8 file_format;               /* What file format version is this database? */
 | |
|   u8 safety_level;              /* How aggressive at synching data to disk */
 | |
|   u8 want_to_close;             /* Close after all VDBEs are deallocated */
 | |
|   u8 temp_store;                /* 1=file, 2=memory, 0=compile-time default */
 | |
|   u8 onError;                   /* Default conflict algorithm */
 | |
|   int next_cookie;              /* Next value of aDb[0].schema_cookie */
 | |
|   int cache_size;               /* Number of pages to use in the cache */
 | |
|   int nTable;                   /* Number of tables in the database */
 | |
|   void *pBusyArg;               /* 1st Argument to the busy callback */
 | |
|   int (*xBusyCallback)(void *,const char*,int);  /* The busy callback */
 | |
|   void *pCommitArg;             /* Argument to xCommitCallback() */   
 | |
|   int (*xCommitCallback)(void*);/* Invoked at every commit. */
 | |
|   Hash aFunc;                   /* All functions that can be in SQL exprs */
 | |
|   int lastRowid;                /* ROWID of most recent insert (see above) */
 | |
|   int priorNewRowid;            /* Last randomly generated ROWID */
 | |
|   int magic;                    /* Magic number for detect library misuse */
 | |
|   int nChange;                  /* Number of rows changed (see above) */
 | |
|   int lsChange;                 /* Last statement change count (see above) */
 | |
|   int csChange;                 /* Current statement change count (see above) */
 | |
|   struct sqliteInitInfo {       /* Information used during initialization */
 | |
|     int iDb;                       /* When back is being initialized */
 | |
|     int newTnum;                   /* Rootpage of table being initialized */
 | |
|     u8 busy;                       /* TRUE if currently initializing */
 | |
|   } init;
 | |
|   struct Vdbe *pVdbe;           /* List of active virtual machines */
 | |
|   void (*xTrace)(void*,const char*);     /* Trace function */
 | |
|   void *pTraceArg;                       /* Argument to the trace function */
 | |
| #ifndef SQLITE_OMIT_AUTHORIZATION
 | |
|   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*);
 | |
|                                 /* Access authorization function */
 | |
|   void *pAuthArg;               /* 1st argument to the access auth function */
 | |
| #endif
 | |
| #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
 | |
|   int (*xProgress)(void *);     /* The progress callback */
 | |
|   void *pProgressArg;           /* Argument to the progress callback */
 | |
|   int nProgressOps;             /* Number of opcodes for progress callback */
 | |
| #endif
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** Possible values for the sqlite.flags and or Db.flags fields.
 | |
| **
 | |
| ** On sqlite.flags, the SQLITE_InTrans value means that we have
 | |
| ** executed a BEGIN.  On Db.flags, SQLITE_InTrans means a statement
 | |
| ** transaction is active on that particular database file.
 | |
| */
 | |
| #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
 | |
| #define SQLITE_Initialized    0x00000002  /* True after initialization */
 | |
| #define SQLITE_Interrupt      0x00000004  /* Cancel current operation */
 | |
| #define SQLITE_InTrans        0x00000008  /* True if in a transaction */
 | |
| #define SQLITE_InternChanges  0x00000010  /* Uncommitted Hash table changes */
 | |
| #define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
 | |
| #define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
 | |
| #define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
 | |
|                                           /*   DELETE, or UPDATE and return */
 | |
|                                           /*   the count using a callback. */
 | |
| #define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
 | |
|                                           /*   result set is empty */
 | |
| #define SQLITE_ReportTypes    0x00000200  /* Include information on datatypes */
 | |
|                                           /*   in 4th argument of callback */
 | |
| 
 | |
| /*
 | |
| ** Possible values for the sqlite.magic field.
 | |
| ** The numbers are obtained at random and have no special meaning, other
 | |
| ** than being distinct from one another.
 | |
| */
 | |
| #define SQLITE_MAGIC_OPEN     0xa029a697  /* Database is open */
 | |
| #define SQLITE_MAGIC_CLOSED   0x9f3c2d33  /* Database is closed */
 | |
| #define SQLITE_MAGIC_BUSY     0xf03b7906  /* Database currently in use */
 | |
| #define SQLITE_MAGIC_ERROR    0xb5357930  /* An SQLITE_MISUSE error occurred */
 | |
| 
 | |
| /*
 | |
| ** Each SQL function is defined by an instance of the following
 | |
| ** structure.  A pointer to this structure is stored in the sqlite.aFunc
 | |
| ** hash table.  When multiple functions have the same name, the hash table
 | |
| ** points to a linked list of these structures.
 | |
| */
 | |
| struct FuncDef {
 | |
|   void (*xFunc)(sqlite_func*,int,const char**);  /* Regular function */
 | |
|   void (*xStep)(sqlite_func*,int,const char**);  /* Aggregate function step */
 | |
|   void (*xFinalize)(sqlite_func*);           /* Aggregate function finializer */
 | |
|   signed char nArg;         /* Number of arguments.  -1 means unlimited */
 | |
|   signed char dataType;     /* Arg that determines datatype.  -1=NUMERIC, */
 | |
|                             /* -2=TEXT. -3=SQLITE_ARGS */
 | |
|   u8 includeTypes;          /* Add datatypes to args of xFunc and xStep */
 | |
|   void *pUserData;          /* User data parameter */
 | |
|   FuncDef *pNext;           /* Next function with same name */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** information about each column of an SQL table is held in an instance
 | |
| ** of this structure.
 | |
| */
 | |
| struct Column {
 | |
|   char *zName;     /* Name of this column */
 | |
|   char *zDflt;     /* Default value of this column */
 | |
|   char *zType;     /* Data type for this column */
 | |
|   u8 notNull;      /* True if there is a NOT NULL constraint */
 | |
|   u8 isPrimKey;    /* True if this column is part of the PRIMARY KEY */
 | |
|   u8 sortOrder;    /* Some combination of SQLITE_SO_... values */
 | |
|   u8 dottedName;   /* True if zName contains a "." character */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** The allowed sort orders.
 | |
| **
 | |
| ** The TEXT and NUM values use bits that do not overlap with DESC and ASC.
 | |
| ** That way the two can be combined into a single number.
 | |
| */
 | |
| #define SQLITE_SO_UNK       0  /* Use the default collating type.  (SCT_NUM) */
 | |
| #define SQLITE_SO_TEXT      2  /* Sort using memcmp() */
 | |
| #define SQLITE_SO_NUM       4  /* Sort using sqliteCompare() */
 | |
| #define SQLITE_SO_TYPEMASK  6  /* Mask to extract the collating sequence */
 | |
| #define SQLITE_SO_ASC       0  /* Sort in ascending order */
 | |
| #define SQLITE_SO_DESC      1  /* Sort in descending order */
 | |
| #define SQLITE_SO_DIRMASK   1  /* Mask to extract the sort direction */
 | |
| 
 | |
| /*
 | |
| ** Each SQL table is represented in memory by an instance of the
 | |
| ** following structure.
 | |
| **
 | |
| ** Table.zName is the name of the table.  The case of the original
 | |
| ** CREATE TABLE statement is stored, but case is not significant for
 | |
| ** comparisons.
 | |
| **
 | |
| ** Table.nCol is the number of columns in this table.  Table.aCol is a
 | |
| ** pointer to an array of Column structures, one for each column.
 | |
| **
 | |
| ** If the table has an INTEGER PRIMARY KEY, then Table.iPKey is the index of
 | |
| ** the column that is that key.   Otherwise Table.iPKey is negative.  Note
 | |
| ** that the datatype of the PRIMARY KEY must be INTEGER for this field to
 | |
| ** be set.  An INTEGER PRIMARY KEY is used as the rowid for each row of
 | |
| ** the table.  If a table has no INTEGER PRIMARY KEY, then a random rowid
 | |
| ** is generated for each row of the table.  Table.hasPrimKey is true if
 | |
| ** the table has any PRIMARY KEY, INTEGER or otherwise.
 | |
| **
 | |
| ** Table.tnum is the page number for the root BTree page of the table in the
 | |
| ** database file.  If Table.iDb is the index of the database table backend
 | |
| ** in sqlite.aDb[].  0 is for the main database and 1 is for the file that
 | |
| ** holds temporary tables and indices.  If Table.isTransient
 | |
| ** is true, then the table is stored in a file that is automatically deleted
 | |
| ** when the VDBE cursor to the table is closed.  In this case Table.tnum 
 | |
| ** refers VDBE cursor number that holds the table open, not to the root
 | |
| ** page number.  Transient tables are used to hold the results of a
 | |
| ** sub-query that appears instead of a real table name in the FROM clause 
 | |
| ** of a SELECT statement.
 | |
| */
 | |
| struct Table {
 | |
|   char *zName;     /* Name of the table */
 | |
|   int nCol;        /* Number of columns in this table */
 | |
|   Column *aCol;    /* Information about each column */
 | |
|   int iPKey;       /* If not less then 0, use aCol[iPKey] as the primary key */
 | |
|   Index *pIndex;   /* List of SQL indexes on this table. */
 | |
|   int tnum;        /* Root BTree node for this table (see note above) */
 | |
|   Select *pSelect; /* NULL for tables.  Points to definition if a view. */
 | |
|   u8 readOnly;     /* True if this table should not be written by the user */
 | |
|   u8 iDb;          /* Index into sqlite.aDb[] of the backend for this table */
 | |
|   u8 isTransient;  /* True if automatically deleted when VDBE finishes */
 | |
|   u8 hasPrimKey;   /* True if there exists a primary key */
 | |
|   u8 keyConf;      /* What to do in case of uniqueness conflict on iPKey */
 | |
|   Trigger *pTrigger; /* List of SQL triggers on this table */
 | |
|   FKey *pFKey;       /* Linked list of all foreign keys in this table */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** Each foreign key constraint is an instance of the following structure.
 | |
| **
 | |
| ** A foreign key is associated with two tables.  The "from" table is
 | |
| ** the table that contains the REFERENCES clause that creates the foreign
 | |
| ** key.  The "to" table is the table that is named in the REFERENCES clause.
 | |
| ** Consider this example:
 | |
| **
 | |
| **     CREATE TABLE ex1(
 | |
| **       a INTEGER PRIMARY KEY,
 | |
| **       b INTEGER CONSTRAINT fk1 REFERENCES ex2(x)
 | |
| **     );
 | |
| **
 | |
| ** For foreign key "fk1", the from-table is "ex1" and the to-table is "ex2".
 | |
| **
 | |
| ** Each REFERENCES clause generates an instance of the following structure
 | |
| ** which is attached to the from-table.  The to-table need not exist when
 | |
| ** the from-table is created.  The existance of the to-table is not checked
 | |
| ** until an attempt is made to insert data into the from-table.
 | |
| **
 | |
| ** The sqlite.aFKey hash table stores pointers to this structure
 | |
| ** given the name of a to-table.  For each to-table, all foreign keys
 | |
| ** associated with that table are on a linked list using the FKey.pNextTo
 | |
| ** field.
 | |
| */
 | |
| struct FKey {
 | |
|   Table *pFrom;     /* The table that constains the REFERENCES clause */
 | |
|   FKey *pNextFrom;  /* Next foreign key in pFrom */
 | |
|   char *zTo;        /* Name of table that the key points to */
 | |
|   FKey *pNextTo;    /* Next foreign key that points to zTo */
 | |
|   int nCol;         /* Number of columns in this key */
 | |
|   struct sColMap {  /* Mapping of columns in pFrom to columns in zTo */
 | |
|     int iFrom;         /* Index of column in pFrom */
 | |
|     char *zCol;        /* Name of column in zTo.  If 0 use PRIMARY KEY */
 | |
|   } *aCol;          /* One entry for each of nCol column s */
 | |
|   u8 isDeferred;    /* True if constraint checking is deferred till COMMIT */
 | |
|   u8 updateConf;    /* How to resolve conflicts that occur on UPDATE */
 | |
|   u8 deleteConf;    /* How to resolve conflicts that occur on DELETE */
 | |
|   u8 insertConf;    /* How to resolve conflicts that occur on INSERT */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** SQLite supports many different ways to resolve a contraint
 | |
| ** error.  ROLLBACK processing means that a constraint violation
 | |
| ** causes the operation in process to fail and for the current transaction
 | |
| ** to be rolled back.  ABORT processing means the operation in process
 | |
| ** fails and any prior changes from that one operation are backed out,
 | |
| ** but the transaction is not rolled back.  FAIL processing means that
 | |
| ** the operation in progress stops and returns an error code.  But prior
 | |
| ** changes due to the same operation are not backed out and no rollback
 | |
| ** occurs.  IGNORE means that the particular row that caused the constraint
 | |
| ** error is not inserted or updated.  Processing continues and no error
 | |
| ** is returned.  REPLACE means that preexisting database rows that caused
 | |
| ** a UNIQUE constraint violation are removed so that the new insert or
 | |
| ** update can proceed.  Processing continues and no error is reported.
 | |
| **
 | |
| ** RESTRICT, SETNULL, and CASCADE actions apply only to foreign keys.
 | |
| ** RESTRICT is the same as ABORT for IMMEDIATE foreign keys and the
 | |
| ** same as ROLLBACK for DEFERRED keys.  SETNULL means that the foreign
 | |
| ** key is set to NULL.  CASCADE means that a DELETE or UPDATE of the
 | |
| ** referenced table row is propagated into the row that holds the
 | |
| ** foreign key.
 | |
| ** 
 | |
| ** The following symbolic values are used to record which type
 | |
| ** of action to take.
 | |
| */
 | |
| #define OE_None     0   /* There is no constraint to check */
 | |
| #define OE_Rollback 1   /* Fail the operation and rollback the transaction */
 | |
| #define OE_Abort    2   /* Back out changes but do no rollback transaction */
 | |
| #define OE_Fail     3   /* Stop the operation but leave all prior changes */
 | |
| #define OE_Ignore   4   /* Ignore the error. Do not do the INSERT or UPDATE */
 | |
| #define OE_Replace  5   /* Delete existing record, then do INSERT or UPDATE */
 | |
| 
 | |
| #define OE_Restrict 6   /* OE_Abort for IMMEDIATE, OE_Rollback for DEFERRED */
 | |
| #define OE_SetNull  7   /* Set the foreign key value to NULL */
 | |
| #define OE_SetDflt  8   /* Set the foreign key value to its default */
 | |
| #define OE_Cascade  9   /* Cascade the changes */
 | |
| 
 | |
| #define OE_Default  99  /* Do whatever the default action is */
 | |
| 
 | |
| /*
 | |
| ** Each SQL index is represented in memory by an
 | |
| ** instance of the following structure.
 | |
| **
 | |
| ** The columns of the table that are to be indexed are described
 | |
| ** by the aiColumn[] field of this structure.  For example, suppose
 | |
| ** we have the following table and index:
 | |
| **
 | |
| **     CREATE TABLE Ex1(c1 int, c2 int, c3 text);
 | |
| **     CREATE INDEX Ex2 ON Ex1(c3,c1);
 | |
| **
 | |
| ** In the Table structure describing Ex1, nCol==3 because there are
 | |
| ** three columns in the table.  In the Index structure describing
 | |
| ** Ex2, nColumn==2 since 2 of the 3 columns of Ex1 are indexed.
 | |
| ** The value of aiColumn is {2, 0}.  aiColumn[0]==2 because the 
 | |
| ** first column to be indexed (c3) has an index of 2 in Ex1.aCol[].
 | |
| ** The second column to be indexed (c1) has an index of 0 in
 | |
| ** Ex1.aCol[], hence Ex2.aiColumn[1]==0.
 | |
| **
 | |
| ** The Index.onError field determines whether or not the indexed columns
 | |
| ** must be unique and what to do if they are not.  When Index.onError=OE_None,
 | |
| ** it means this is not a unique index.  Otherwise it is a unique index
 | |
| ** and the value of Index.onError indicate the which conflict resolution 
 | |
| ** algorithm to employ whenever an attempt is made to insert a non-unique
 | |
| ** element.
 | |
| */
 | |
| struct Index {
 | |
|   char *zName;     /* Name of this index */
 | |
|   int nColumn;     /* Number of columns in the table used by this index */
 | |
|   int *aiColumn;   /* Which columns are used by this index.  1st is 0 */
 | |
|   Table *pTable;   /* The SQL table being indexed */
 | |
|   int tnum;        /* Page containing root of this index in database file */
 | |
|   u8 onError;      /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
 | |
|   u8 autoIndex;    /* True if is automatically created (ex: by UNIQUE) */
 | |
|   u8 iDb;          /* Index in sqlite.aDb[] of where this index is stored */
 | |
|   Index *pNext;    /* The next index associated with the same table */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** Each token coming out of the lexer is an instance of
 | |
| ** this structure.  Tokens are also used as part of an expression.
 | |
| **
 | |
| ** Note if Token.z==0 then Token.dyn and Token.n are undefined and
 | |
| ** may contain random values.  Do not make any assuptions about Token.dyn
 | |
| ** and Token.n when Token.z==0.
 | |
| */
 | |
| struct Token {
 | |
|   const char *z;      /* Text of the token.  Not NULL-terminated! */
 | |
|   unsigned dyn  : 1;  /* True for malloced memory, false for static */
 | |
|   unsigned n    : 31; /* Number of characters in this token */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** Each node of an expression in the parse tree is an instance
 | |
| ** of this structure.
 | |
| **
 | |
| ** Expr.op is the opcode.  The integer parser token codes are reused
 | |
| ** as opcodes here.  For example, the parser defines TK_GE to be an integer
 | |
| ** code representing the ">=" operator.  This same integer code is reused
 | |
| ** to represent the greater-than-or-equal-to operator in the expression
 | |
| ** tree.
 | |
| **
 | |
| ** Expr.pRight and Expr.pLeft are subexpressions.  Expr.pList is a list
 | |
| ** of argument if the expression is a function.
 | |
| **
 | |
| ** Expr.token is the operator token for this node.  For some expressions
 | |
| ** that have subexpressions, Expr.token can be the complete text that gave
 | |
| ** rise to the Expr.  In the latter case, the token is marked as being
 | |
| ** a compound token.
 | |
| **
 | |
| ** An expression of the form ID or ID.ID refers to a column in a table.
 | |
| ** For such expressions, Expr.op is set to TK_COLUMN and Expr.iTable is
 | |
| ** the integer cursor number of a VDBE cursor pointing to that table and
 | |
| ** Expr.iColumn is the column number for the specific column.  If the
 | |
| ** expression is used as a result in an aggregate SELECT, then the
 | |
| ** value is also stored in the Expr.iAgg column in the aggregate so that
 | |
| ** it can be accessed after all aggregates are computed.
 | |
| **
 | |
| ** If the expression is a function, the Expr.iTable is an integer code
 | |
| ** representing which function.  If the expression is an unbound variable
 | |
| ** marker (a question mark character '?' in the original SQL) then the
 | |
| ** Expr.iTable holds the index number for that variable.
 | |
| **
 | |
| ** The Expr.pSelect field points to a SELECT statement.  The SELECT might
 | |
| ** be the right operand of an IN operator.  Or, if a scalar SELECT appears
 | |
| ** in an expression the opcode is TK_SELECT and Expr.pSelect is the only
 | |
| ** operand.
 | |
| */
 | |
| struct Expr {
 | |
|   u8 op;                 /* Operation performed by this node */
 | |
|   u8 dataType;           /* Either SQLITE_SO_TEXT or SQLITE_SO_NUM */
 | |
|   u8 iDb;                /* Database referenced by this expression */
 | |
|   u8 flags;              /* Various flags.  See below */
 | |
|   Expr *pLeft, *pRight;  /* Left and right subnodes */
 | |
|   ExprList *pList;       /* A list of expressions used as function arguments
 | |
|                          ** or in "<expr> IN (<expr-list)" */
 | |
|   Token token;           /* An operand token */
 | |
|   Token span;            /* Complete text of the expression */
 | |
|   int iTable, iColumn;   /* When op==TK_COLUMN, then this expr node means the
 | |
|                          ** iColumn-th field of the iTable-th table. */
 | |
|   int iAgg;              /* When op==TK_COLUMN and pParse->useAgg==TRUE, pull
 | |
|                          ** result from the iAgg-th element of the aggregator */
 | |
|   Select *pSelect;       /* When the expression is a sub-select.  Also the
 | |
|                          ** right side of "<expr> IN (<select>)" */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** The following are the meanings of bits in the Expr.flags field.
 | |
| */
 | |
| #define EP_FromJoin     0x0001  /* Originated in ON or USING clause of a join */
 | |
| 
 | |
| /*
 | |
| ** These macros can be used to test, set, or clear bits in the 
 | |
| ** Expr.flags field.
 | |
| */
 | |
| #define ExprHasProperty(E,P)     (((E)->flags&(P))==(P))
 | |
| #define ExprHasAnyProperty(E,P)  (((E)->flags&(P))!=0)
 | |
| #define ExprSetProperty(E,P)     (E)->flags|=(P)
 | |
| #define ExprClearProperty(E,P)   (E)->flags&=~(P)
 | |
| 
 | |
| /*
 | |
| ** A list of expressions.  Each expression may optionally have a
 | |
| ** name.  An expr/name combination can be used in several ways, such
 | |
| ** as the list of "expr AS ID" fields following a "SELECT" or in the
 | |
| ** list of "ID = expr" items in an UPDATE.  A list of expressions can
 | |
| ** also be used as the argument to a function, in which case the a.zName
 | |
| ** field is not used.
 | |
| */
 | |
| struct ExprList {
 | |
|   int nExpr;             /* Number of expressions on the list */
 | |
|   int nAlloc;            /* Number of entries allocated below */
 | |
|   struct ExprList_item {
 | |
|     Expr *pExpr;           /* The list of expressions */
 | |
|     char *zName;           /* Token associated with this expression */
 | |
|     u8 sortOrder;          /* 1 for DESC or 0 for ASC */
 | |
|     u8 isAgg;              /* True if this is an aggregate like count(*) */
 | |
|     u8 done;               /* A flag to indicate when processing is finished */
 | |
|   } *a;                  /* One entry for each expression */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** An instance of this structure can hold a simple list of identifiers,
 | |
| ** such as the list "a,b,c" in the following statements:
 | |
| **
 | |
| **      INSERT INTO t(a,b,c) VALUES ...;
 | |
| **      CREATE INDEX idx ON t(a,b,c);
 | |
| **      CREATE TRIGGER trig BEFORE UPDATE ON t(a,b,c) ...;
 | |
| **
 | |
| ** The IdList.a.idx field is used when the IdList represents the list of
 | |
| ** column names after a table name in an INSERT statement.  In the statement
 | |
| **
 | |
| **     INSERT INTO t(a,b,c) ...
 | |
| **
 | |
| ** If "a" is the k-th column of table "t", then IdList.a[0].idx==k.
 | |
| */
 | |
| struct IdList {
 | |
|   int nId;         /* Number of identifiers on the list */
 | |
|   int nAlloc;      /* Number of entries allocated for a[] below */
 | |
|   struct IdList_item {
 | |
|     char *zName;      /* Name of the identifier */
 | |
|     int idx;          /* Index in some Table.aCol[] of a column named zName */
 | |
|   } *a;
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** The following structure describes the FROM clause of a SELECT statement.
 | |
| ** Each table or subquery in the FROM clause is a separate element of
 | |
| ** the SrcList.a[] array.
 | |
| **
 | |
| ** With the addition of multiple database support, the following structure
 | |
| ** can also be used to describe a particular table such as the table that
 | |
| ** is modified by an INSERT, DELETE, or UPDATE statement.  In standard SQL,
 | |
| ** such a table must be a simple name: ID.  But in SQLite, the table can
 | |
| ** now be identified by a database name, a dot, then the table name: ID.ID.
 | |
| */
 | |
| struct SrcList {
 | |
|   u16 nSrc;        /* Number of tables or subqueries in the FROM clause */
 | |
|   u16 nAlloc;      /* Number of entries allocated in a[] below */
 | |
|   struct SrcList_item {
 | |
|     char *zDatabase;  /* Name of database holding this table */
 | |
|     char *zName;      /* Name of the table */
 | |
|     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
 | |
|     Table *pTab;      /* An SQL table corresponding to zName */
 | |
|     Select *pSelect;  /* A SELECT statement used in place of a table name */
 | |
|     int jointype;     /* Type of join between this table and the next */
 | |
|     int iCursor;      /* The VDBE cursor number used to access this table */
 | |
|     Expr *pOn;        /* The ON clause of a join */
 | |
|     IdList *pUsing;   /* The USING clause of a join */
 | |
|   } a[1];             /* One entry for each identifier on the list */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** Permitted values of the SrcList.a.jointype field
 | |
| */
 | |
| #define JT_INNER     0x0001    /* Any kind of inner or cross join */
 | |
| #define JT_NATURAL   0x0002    /* True for a "natural" join */
 | |
| #define JT_LEFT      0x0004    /* Left outer join */
 | |
| #define JT_RIGHT     0x0008    /* Right outer join */
 | |
| #define JT_OUTER     0x0010    /* The "OUTER" keyword is present */
 | |
| #define JT_ERROR     0x0020    /* unknown or unsupported join type */
 | |
| 
 | |
| /*
 | |
| ** For each nested loop in a WHERE clause implementation, the WhereInfo
 | |
| ** structure contains a single instance of this structure.  This structure
 | |
| ** is intended to be private the the where.c module and should not be
 | |
| ** access or modified by other modules.
 | |
| */
 | |
| struct WhereLevel {
 | |
|   int iMem;            /* Memory cell used by this level */
 | |
|   Index *pIdx;         /* Index used */
 | |
|   int iCur;            /* Cursor number used for this index */
 | |
|   int score;           /* How well this indexed scored */
 | |
|   int brk;             /* Jump here to break out of the loop */
 | |
|   int cont;            /* Jump here to continue with the next loop cycle */
 | |
|   int op, p1, p2;      /* Opcode used to terminate the loop */
 | |
|   int iLeftJoin;       /* Memory cell used to implement LEFT OUTER JOIN */
 | |
|   int top;             /* First instruction of interior of the loop */
 | |
|   int inOp, inP1, inP2;/* Opcode used to implement an IN operator */
 | |
|   int bRev;            /* Do the scan in the reverse direction */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** The WHERE clause processing routine has two halves.  The
 | |
| ** first part does the start of the WHERE loop and the second
 | |
| ** half does the tail of the WHERE loop.  An instance of
 | |
| ** this structure is returned by the first half and passed
 | |
| ** into the second half to give some continuity.
 | |
| */
 | |
| struct WhereInfo {
 | |
|   Parse *pParse;
 | |
|   SrcList *pTabList;   /* List of tables in the join */
 | |
|   int iContinue;       /* Jump here to continue with next record */
 | |
|   int iBreak;          /* Jump here to break out of the loop */
 | |
|   int nLevel;          /* Number of nested loop */
 | |
|   int savedNTab;       /* Value of pParse->nTab before WhereBegin() */
 | |
|   int peakNTab;        /* Value of pParse->nTab after WhereBegin() */
 | |
|   WhereLevel a[1];     /* Information about each nest loop in the WHERE */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** An instance of the following structure contains all information
 | |
| ** needed to generate code for a single SELECT statement.
 | |
| **
 | |
| ** The zSelect field is used when the Select structure must be persistent.
 | |
| ** Normally, the expression tree points to tokens in the original input
 | |
| ** string that encodes the select.  But if the Select structure must live
 | |
| ** longer than its input string (for example when it is used to describe
 | |
| ** a VIEW) we have to make a copy of the input string so that the nodes
 | |
| ** of the expression tree will have something to point to.  zSelect is used
 | |
| ** to hold that copy.
 | |
| **
 | |
| ** nLimit is set to -1 if there is no LIMIT clause.  nOffset is set to 0.
 | |
| ** If there is a LIMIT clause, the parser sets nLimit to the value of the
 | |
| ** limit and nOffset to the value of the offset (or 0 if there is not
 | |
| ** offset).  But later on, nLimit and nOffset become the memory locations
 | |
| ** in the VDBE that record the limit and offset counters.
 | |
| */
 | |
| struct Select {
 | |
|   ExprList *pEList;      /* The fields of the result */
 | |
|   u8 op;                 /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
 | |
|   u8 isDistinct;         /* True if the DISTINCT keyword is present */
 | |
|   SrcList *pSrc;         /* The FROM clause */
 | |
|   Expr *pWhere;          /* The WHERE clause */
 | |
|   ExprList *pGroupBy;    /* The GROUP BY clause */
 | |
|   Expr *pHaving;         /* The HAVING clause */
 | |
|   ExprList *pOrderBy;    /* The ORDER BY clause */
 | |
|   Select *pPrior;        /* Prior select in a compound select statement */
 | |
|   int nLimit, nOffset;   /* LIMIT and OFFSET values.  -1 means not used */
 | |
|   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
 | |
|   char *zSelect;         /* Complete text of the SELECT command */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** The results of a select can be distributed in several ways.
 | |
| */
 | |
| #define SRT_Callback     1  /* Invoke a callback with each row of result */
 | |
| #define SRT_Mem          2  /* Store result in a memory cell */
 | |
| #define SRT_Set          3  /* Store result as unique keys in a table */
 | |
| #define SRT_Union        5  /* Store result as keys in a table */
 | |
| #define SRT_Except       6  /* Remove result from a UNION table */
 | |
| #define SRT_Table        7  /* Store result as data with a unique key */
 | |
| #define SRT_TempTable    8  /* Store result in a trasient table */
 | |
| #define SRT_Discard      9  /* Do not save the results anywhere */
 | |
| #define SRT_Sorter      10  /* Store results in the sorter */
 | |
| #define SRT_Subroutine  11  /* Call a subroutine to handle results */
 | |
| 
 | |
| /*
 | |
| ** When a SELECT uses aggregate functions (like "count(*)" or "avg(f1)")
 | |
| ** we have to do some additional analysis of expressions.  An instance
 | |
| ** of the following structure holds information about a single subexpression
 | |
| ** somewhere in the SELECT statement.  An array of these structures holds
 | |
| ** all the information we need to generate code for aggregate
 | |
| ** expressions.
 | |
| **
 | |
| ** Note that when analyzing a SELECT containing aggregates, both
 | |
| ** non-aggregate field variables and aggregate functions are stored
 | |
| ** in the AggExpr array of the Parser structure.
 | |
| **
 | |
| ** The pExpr field points to an expression that is part of either the
 | |
| ** field list, the GROUP BY clause, the HAVING clause or the ORDER BY
 | |
| ** clause.  The expression will be freed when those clauses are cleaned
 | |
| ** up.  Do not try to delete the expression attached to AggExpr.pExpr.
 | |
| **
 | |
| ** If AggExpr.pExpr==0, that means the expression is "count(*)".
 | |
| */
 | |
| struct AggExpr {
 | |
|   int isAgg;        /* if TRUE contains an aggregate function */
 | |
|   Expr *pExpr;      /* The expression */
 | |
|   FuncDef *pFunc;   /* Information about the aggregate function */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** An SQL parser context.  A copy of this structure is passed through
 | |
| ** the parser and down into all the parser action routine in order to
 | |
| ** carry around information that is global to the entire parse.
 | |
| */
 | |
| struct Parse {
 | |
|   sqlite *db;          /* The main database structure */
 | |
|   int rc;              /* Return code from execution */
 | |
|   char *zErrMsg;       /* An error message */
 | |
|   Token sErrToken;     /* The token at which the error occurred */
 | |
|   Token sFirstToken;   /* The first token parsed */
 | |
|   Token sLastToken;    /* The last token parsed */
 | |
|   const char *zTail;   /* All SQL text past the last semicolon parsed */
 | |
|   Table *pNewTable;    /* A table being constructed by CREATE TABLE */
 | |
|   Vdbe *pVdbe;         /* An engine for executing database bytecode */
 | |
|   u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
 | |
|   u8 explain;          /* True if the EXPLAIN flag is found on the query */
 | |
|   u8 nameClash;        /* A permanent table name clashes with temp table name */
 | |
|   u8 useAgg;           /* If true, extract field values from the aggregator
 | |
|                        ** while generating expressions.  Normally false */
 | |
|   int nErr;            /* Number of errors seen */
 | |
|   int nTab;            /* Number of previously allocated VDBE cursors */
 | |
|   int nMem;            /* Number of memory cells used so far */
 | |
|   int nSet;            /* Number of sets used so far */
 | |
|   int nAgg;            /* Number of aggregate expressions */
 | |
|   int nVar;            /* Number of '?' variables seen in the SQL so far */
 | |
|   AggExpr *aAgg;       /* An array of aggregate expressions */
 | |
|   const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
 | |
|   Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
 | |
|   TriggerStack *trigStack;  /* Trigger actions being coded */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** An instance of the following structure can be declared on a stack and used
 | |
| ** to save the Parse.zAuthContext value so that it can be restored later.
 | |
| */
 | |
| struct AuthContext {
 | |
|   const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
 | |
|   Parse *pParse;              /* The Parse structure */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** Bitfield flags for P2 value in OP_PutIntKey and OP_Delete
 | |
| */
 | |
| #define OPFLAG_NCHANGE   1    /* Set to update db->nChange */
 | |
| #define OPFLAG_LASTROWID 2    /* Set to update db->lastRowid */
 | |
| #define OPFLAG_CSCHANGE  4    /* Set to update db->csChange */
 | |
| 
 | |
| /*
 | |
|  * Each trigger present in the database schema is stored as an instance of
 | |
|  * struct Trigger. 
 | |
|  *
 | |
|  * Pointers to instances of struct Trigger are stored in two ways.
 | |
|  * 1. In the "trigHash" hash table (part of the sqlite* that represents the 
 | |
|  *    database). This allows Trigger structures to be retrieved by name.
 | |
|  * 2. All triggers associated with a single table form a linked list, using the
 | |
|  *    pNext member of struct Trigger. A pointer to the first element of the
 | |
|  *    linked list is stored as the "pTrigger" member of the associated
 | |
|  *    struct Table.
 | |
|  *
 | |
|  * The "step_list" member points to the first element of a linked list
 | |
|  * containing the SQL statements specified as the trigger program.
 | |
|  */
 | |
| struct Trigger {
 | |
|   char *name;             /* The name of the trigger                        */
 | |
|   char *table;            /* The table or view to which the trigger applies */
 | |
|   u8 iDb;                 /* Database containing this trigger               */
 | |
|   u8 iTabDb;              /* Database containing Trigger.table              */
 | |
|   u8 op;                  /* One of TK_DELETE, TK_UPDATE, TK_INSERT         */
 | |
|   u8 tr_tm;               /* One of TK_BEFORE, TK_AFTER */
 | |
|   Expr *pWhen;            /* The WHEN clause of the expresion (may be NULL) */
 | |
|   IdList *pColumns;       /* If this is an UPDATE OF <column-list> trigger,
 | |
|                              the <column-list> is stored here */
 | |
|   int foreach;            /* One of TK_ROW or TK_STATEMENT */
 | |
|   Token nameToken;        /* Token containing zName. Use during parsing only */
 | |
| 
 | |
|   TriggerStep *step_list; /* Link list of trigger program steps             */
 | |
|   Trigger *pNext;         /* Next trigger associated with the table */
 | |
| };
 | |
| 
 | |
| /*
 | |
|  * An instance of struct TriggerStep is used to store a single SQL statement
 | |
|  * that is a part of a trigger-program. 
 | |
|  *
 | |
|  * Instances of struct TriggerStep are stored in a singly linked list (linked
 | |
|  * using the "pNext" member) referenced by the "step_list" member of the 
 | |
|  * associated struct Trigger instance. The first element of the linked list is
 | |
|  * the first step of the trigger-program.
 | |
|  * 
 | |
|  * The "op" member indicates whether this is a "DELETE", "INSERT", "UPDATE" or
 | |
|  * "SELECT" statement. The meanings of the other members is determined by the 
 | |
|  * value of "op" as follows:
 | |
|  *
 | |
|  * (op == TK_INSERT)
 | |
|  * orconf    -> stores the ON CONFLICT algorithm
 | |
|  * pSelect   -> If this is an INSERT INTO ... SELECT ... statement, then
 | |
|  *              this stores a pointer to the SELECT statement. Otherwise NULL.
 | |
|  * target    -> A token holding the name of the table to insert into.
 | |
|  * pExprList -> If this is an INSERT INTO ... VALUES ... statement, then
 | |
|  *              this stores values to be inserted. Otherwise NULL.
 | |
|  * pIdList   -> If this is an INSERT INTO ... (<column-names>) VALUES ... 
 | |
|  *              statement, then this stores the column-names to be
 | |
|  *              inserted into.
 | |
|  *
 | |
|  * (op == TK_DELETE)
 | |
|  * target    -> A token holding the name of the table to delete from.
 | |
|  * pWhere    -> The WHERE clause of the DELETE statement if one is specified.
 | |
|  *              Otherwise NULL.
 | |
|  * 
 | |
|  * (op == TK_UPDATE)
 | |
|  * target    -> A token holding the name of the table to update rows of.
 | |
|  * pWhere    -> The WHERE clause of the UPDATE statement if one is specified.
 | |
|  *              Otherwise NULL.
 | |
|  * pExprList -> A list of the columns to update and the expressions to update
 | |
|  *              them to. See sqliteUpdate() documentation of "pChanges"
 | |
|  *              argument.
 | |
|  * 
 | |
|  */
 | |
| struct TriggerStep {
 | |
|   int op;              /* One of TK_DELETE, TK_UPDATE, TK_INSERT, TK_SELECT */
 | |
|   int orconf;          /* OE_Rollback etc. */
 | |
|   Trigger *pTrig;      /* The trigger that this step is a part of */
 | |
| 
 | |
|   Select *pSelect;     /* Valid for SELECT and sometimes 
 | |
| 			  INSERT steps (when pExprList == 0) */
 | |
|   Token target;        /* Valid for DELETE, UPDATE, INSERT steps */
 | |
|   Expr *pWhere;        /* Valid for DELETE, UPDATE steps */
 | |
|   ExprList *pExprList; /* Valid for UPDATE statements and sometimes 
 | |
| 			   INSERT steps (when pSelect == 0)         */
 | |
|   IdList *pIdList;     /* Valid for INSERT statements only */
 | |
| 
 | |
|   TriggerStep * pNext; /* Next in the link-list */
 | |
| };
 | |
| 
 | |
| /*
 | |
|  * An instance of struct TriggerStack stores information required during code
 | |
|  * generation of a single trigger program. While the trigger program is being
 | |
|  * coded, its associated TriggerStack instance is pointed to by the
 | |
|  * "pTriggerStack" member of the Parse structure.
 | |
|  *
 | |
|  * The pTab member points to the table that triggers are being coded on. The 
 | |
|  * newIdx member contains the index of the vdbe cursor that points at the temp
 | |
|  * table that stores the new.* references. If new.* references are not valid
 | |
|  * for the trigger being coded (for example an ON DELETE trigger), then newIdx
 | |
|  * is set to -1. The oldIdx member is analogous to newIdx, for old.* references.
 | |
|  *
 | |
|  * The ON CONFLICT policy to be used for the trigger program steps is stored 
 | |
|  * as the orconf member. If this is OE_Default, then the ON CONFLICT clause 
 | |
|  * specified for individual triggers steps is used.
 | |
|  *
 | |
|  * struct TriggerStack has a "pNext" member, to allow linked lists to be
 | |
|  * constructed. When coding nested triggers (triggers fired by other triggers)
 | |
|  * each nested trigger stores its parent trigger's TriggerStack as the "pNext" 
 | |
|  * pointer. Once the nested trigger has been coded, the pNext value is restored
 | |
|  * to the pTriggerStack member of the Parse stucture and coding of the parent
 | |
|  * trigger continues.
 | |
|  *
 | |
|  * Before a nested trigger is coded, the linked list pointed to by the 
 | |
|  * pTriggerStack is scanned to ensure that the trigger is not about to be coded
 | |
|  * recursively. If this condition is detected, the nested trigger is not coded.
 | |
|  */
 | |
| struct TriggerStack {
 | |
|   Table *pTab;         /* Table that triggers are currently being coded on */
 | |
|   int newIdx;          /* Index of vdbe cursor to "new" temp table */
 | |
|   int oldIdx;          /* Index of vdbe cursor to "old" temp table */
 | |
|   int orconf;          /* Current orconf policy */
 | |
|   int ignoreJump;      /* where to jump to for a RAISE(IGNORE) */
 | |
|   Trigger *pTrigger;   /* The trigger currently being coded */
 | |
|   TriggerStack *pNext; /* Next trigger down on the trigger stack */
 | |
| };
 | |
| 
 | |
| /*
 | |
| ** The following structure contains information used by the sqliteFix...
 | |
| ** routines as they walk the parse tree to make database references
 | |
| ** explicit.  
 | |
| */
 | |
| typedef struct DbFixer DbFixer;
 | |
| struct DbFixer {
 | |
|   Parse *pParse;      /* The parsing context.  Error messages written here */
 | |
|   const char *zDb;    /* Make sure all objects are contained in this database */
 | |
|   const char *zType;  /* Type of the container - used for error messages */
 | |
|   const Token *pName; /* Name of the container - used for error messages */
 | |
| };
 | |
| 
 | |
| /*
 | |
|  * This global flag is set for performance testing of triggers. When it is set
 | |
|  * SQLite will perform the overhead of building new and old trigger references 
 | |
|  * even when no triggers exist
 | |
|  */
 | |
| extern int always_code_trigger_setup;
 | |
| 
 | |
| /*
 | |
| ** Internal function prototypes
 | |
| */
 | |
| int sqliteStrICmp(const char *, const char *);
 | |
| int sqliteStrNICmp(const char *, const char *, int);
 | |
| int sqliteHashNoCase(const char *, int);
 | |
| int sqliteIsNumber(const char*);
 | |
| int sqliteCompare(const char *, const char *);
 | |
| int sqliteSortCompare(const char *, const char *);
 | |
| void sqliteRealToSortable(double r, char *);
 | |
| #ifdef MEMORY_DEBUG
 | |
|   void *sqliteMalloc_(int,int,char*,int);
 | |
|   void sqliteFree_(void*,char*,int);
 | |
|   void *sqliteRealloc_(void*,int,char*,int);
 | |
|   char *sqliteStrDup_(const char*,char*,int);
 | |
|   char *sqliteStrNDup_(const char*, int,char*,int);
 | |
|   void sqliteCheckMemory(void*,int);
 | |
| #else
 | |
|   void *sqliteMalloc(int);
 | |
|   void *sqliteMallocRaw(int);
 | |
|   void sqliteFree(void*);
 | |
|   void *sqliteRealloc(void*,int);
 | |
|   char *sqliteStrDup(const char*);
 | |
|   char *sqliteStrNDup(const char*, int);
 | |
| # define sqliteCheckMemory(a,b)
 | |
| #endif
 | |
| char *sqliteMPrintf(const char*, ...);
 | |
| char *sqliteVMPrintf(const char*, va_list);
 | |
| void sqliteSetString(char **, const char *, ...);
 | |
| void sqliteSetNString(char **, ...);
 | |
| void sqliteErrorMsg(Parse*, const char*, ...);
 | |
| void sqliteDequote(char*);
 | |
| int sqliteKeywordCode(const char*, int);
 | |
| int sqliteRunParser(Parse*, const char*, char **);
 | |
| void sqliteExec(Parse*);
 | |
| Expr *sqliteExpr(int, Expr*, Expr*, Token*);
 | |
| void sqliteExprSpan(Expr*,Token*,Token*);
 | |
| Expr *sqliteExprFunction(ExprList*, Token*);
 | |
| void sqliteExprDelete(Expr*);
 | |
| ExprList *sqliteExprListAppend(ExprList*,Expr*,Token*);
 | |
| void sqliteExprListDelete(ExprList*);
 | |
| int sqliteInit(sqlite*, char**);
 | |
| void sqlitePragma(Parse*,Token*,Token*,int);
 | |
| void sqliteResetInternalSchema(sqlite*, int);
 | |
| void sqliteBeginParse(Parse*,int);
 | |
| void sqliteRollbackInternalChanges(sqlite*);
 | |
| void sqliteCommitInternalChanges(sqlite*);
 | |
| Table *sqliteResultSetOfSelect(Parse*,char*,Select*);
 | |
| void sqliteOpenMasterTable(Vdbe *v, int);
 | |
| void sqliteStartTable(Parse*,Token*,Token*,int,int);
 | |
| void sqliteAddColumn(Parse*,Token*);
 | |
| void sqliteAddNotNull(Parse*, int);
 | |
| void sqliteAddPrimaryKey(Parse*, IdList*, int);
 | |
| void sqliteAddColumnType(Parse*,Token*,Token*);
 | |
| void sqliteAddDefaultValue(Parse*,Token*,int);
 | |
| int sqliteCollateType(const char*, int);
 | |
| void sqliteAddCollateType(Parse*, int);
 | |
| void sqliteEndTable(Parse*,Token*,Select*);
 | |
| void sqliteCreateView(Parse*,Token*,Token*,Select*,int);
 | |
| int sqliteViewGetColumnNames(Parse*,Table*);
 | |
| void sqliteDropTable(Parse*, Token*, int);
 | |
| void sqliteDeleteTable(sqlite*, Table*);
 | |
| void sqliteInsert(Parse*, SrcList*, ExprList*, Select*, IdList*, int);
 | |
| IdList *sqliteIdListAppend(IdList*, Token*);
 | |
| int sqliteIdListIndex(IdList*,const char*);
 | |
| SrcList *sqliteSrcListAppend(SrcList*, Token*, Token*);
 | |
| void sqliteSrcListAddAlias(SrcList*, Token*);
 | |
| void sqliteSrcListAssignCursors(Parse*, SrcList*);
 | |
| void sqliteIdListDelete(IdList*);
 | |
| void sqliteSrcListDelete(SrcList*);
 | |
| void sqliteCreateIndex(Parse*,Token*,SrcList*,IdList*,int,Token*,Token*);
 | |
| void sqliteDropIndex(Parse*, SrcList*);
 | |
| void sqliteAddKeyType(Vdbe*, ExprList*);
 | |
| void sqliteAddIdxKeyType(Vdbe*, Index*);
 | |
| int sqliteSelect(Parse*, Select*, int, int, Select*, int, int*);
 | |
| Select *sqliteSelectNew(ExprList*,SrcList*,Expr*,ExprList*,Expr*,ExprList*,
 | |
|                         int,int,int);
 | |
| void sqliteSelectDelete(Select*);
 | |
| void sqliteSelectUnbind(Select*);
 | |
| Table *sqliteSrcListLookup(Parse*, SrcList*);
 | |
| int sqliteIsReadOnly(Parse*, Table*, int);
 | |
| void sqliteDeleteFrom(Parse*, SrcList*, Expr*);
 | |
| void sqliteUpdate(Parse*, SrcList*, ExprList*, Expr*, int);
 | |
| WhereInfo *sqliteWhereBegin(Parse*, SrcList*, Expr*, int, ExprList**);
 | |
| void sqliteWhereEnd(WhereInfo*);
 | |
| void sqliteExprCode(Parse*, Expr*);
 | |
| int sqliteExprCodeExprList(Parse*, ExprList*, int);
 | |
| void sqliteExprIfTrue(Parse*, Expr*, int, int);
 | |
| void sqliteExprIfFalse(Parse*, Expr*, int, int);
 | |
| Table *sqliteFindTable(sqlite*,const char*, const char*);
 | |
| Table *sqliteLocateTable(Parse*,const char*, const char*);
 | |
| Index *sqliteFindIndex(sqlite*,const char*, const char*);
 | |
| void sqliteUnlinkAndDeleteIndex(sqlite*,Index*);
 | |
| void sqliteCopy(Parse*, SrcList*, Token*, Token*, int);
 | |
| void sqliteVacuum(Parse*, Token*);
 | |
| int sqliteRunVacuum(char**, sqlite*);
 | |
| int sqliteGlobCompare(const unsigned char*,const unsigned char*);
 | |
| int sqliteLikeCompare(const unsigned char*,const unsigned char*);
 | |
| char *sqliteTableNameFromToken(Token*);
 | |
| int sqliteExprCheck(Parse*, Expr*, int, int*);
 | |
| int sqliteExprType(Expr*);
 | |
| int sqliteExprCompare(Expr*, Expr*);
 | |
| int sqliteFuncId(Token*);
 | |
| int sqliteExprResolveIds(Parse*, SrcList*, ExprList*, Expr*);
 | |
| int sqliteExprAnalyzeAggregates(Parse*, Expr*);
 | |
| Vdbe *sqliteGetVdbe(Parse*);
 | |
| void sqliteRandomness(int, void*);
 | |
| void sqliteRollbackAll(sqlite*);
 | |
| void sqliteCodeVerifySchema(Parse*, int);
 | |
| void sqliteBeginTransaction(Parse*, int);
 | |
| void sqliteCommitTransaction(Parse*);
 | |
| void sqliteRollbackTransaction(Parse*);
 | |
| int sqliteExprIsConstant(Expr*);
 | |
| int sqliteExprIsInteger(Expr*, int*);
 | |
| int sqliteIsRowid(const char*);
 | |
| void sqliteGenerateRowDelete(sqlite*, Vdbe*, Table*, int, int);
 | |
| void sqliteGenerateRowIndexDelete(sqlite*, Vdbe*, Table*, int, char*);
 | |
| void sqliteGenerateConstraintChecks(Parse*,Table*,int,char*,int,int,int,int);
 | |
| void sqliteCompleteInsertion(Parse*, Table*, int, char*, int, int, int);
 | |
| int sqliteOpenTableAndIndices(Parse*, Table*, int);
 | |
| void sqliteBeginWriteOperation(Parse*, int, int);
 | |
| void sqliteEndWriteOperation(Parse*);
 | |
| Expr *sqliteExprDup(Expr*);
 | |
| void sqliteTokenCopy(Token*, Token*);
 | |
| ExprList *sqliteExprListDup(ExprList*);
 | |
| SrcList *sqliteSrcListDup(SrcList*);
 | |
| IdList *sqliteIdListDup(IdList*);
 | |
| Select *sqliteSelectDup(Select*);
 | |
| FuncDef *sqliteFindFunction(sqlite*,const char*,int,int,int);
 | |
| void sqliteRegisterBuiltinFunctions(sqlite*);
 | |
| void sqliteRegisterDateTimeFunctions(sqlite*);
 | |
| int sqliteSafetyOn(sqlite*);
 | |
| int sqliteSafetyOff(sqlite*);
 | |
| int sqliteSafetyCheck(sqlite*);
 | |
| void sqliteChangeCookie(sqlite*, Vdbe*);
 | |
| void sqliteBeginTrigger(Parse*, Token*,int,int,IdList*,SrcList*,int,Expr*,int);
 | |
| void sqliteFinishTrigger(Parse*, TriggerStep*, Token*);
 | |
| void sqliteDropTrigger(Parse*, SrcList*);
 | |
| void sqliteDropTriggerPtr(Parse*, Trigger*, int);
 | |
| int sqliteTriggersExist(Parse* , Trigger* , int , int , int, ExprList*);
 | |
| int sqliteCodeRowTrigger(Parse*, int, ExprList*, int, Table *, int, int, 
 | |
|                          int, int);
 | |
| void sqliteViewTriggers(Parse*, Table*, Expr*, int, ExprList*);
 | |
| void sqliteDeleteTriggerStep(TriggerStep*);
 | |
| TriggerStep *sqliteTriggerSelectStep(Select*);
 | |
| TriggerStep *sqliteTriggerInsertStep(Token*, IdList*, ExprList*, Select*, int);
 | |
| TriggerStep *sqliteTriggerUpdateStep(Token*, ExprList*, Expr*, int);
 | |
| TriggerStep *sqliteTriggerDeleteStep(Token*, Expr*);
 | |
| void sqliteDeleteTrigger(Trigger*);
 | |
| int sqliteJoinType(Parse*, Token*, Token*, Token*);
 | |
| void sqliteCreateForeignKey(Parse*, IdList*, Token*, IdList*, int);
 | |
| void sqliteDeferForeignKey(Parse*, int);
 | |
| #ifndef SQLITE_OMIT_AUTHORIZATION
 | |
|   void sqliteAuthRead(Parse*,Expr*,SrcList*);
 | |
|   int sqliteAuthCheck(Parse*,int, const char*, const char*, const char*);
 | |
|   void sqliteAuthContextPush(Parse*, AuthContext*, const char*);
 | |
|   void sqliteAuthContextPop(AuthContext*);
 | |
| #else
 | |
| # define sqliteAuthRead(a,b,c)
 | |
| # define sqliteAuthCheck(a,b,c,d,e)    SQLITE_OK
 | |
| # define sqliteAuthContextPush(a,b,c)
 | |
| # define sqliteAuthContextPop(a)  ((void)(a))
 | |
| #endif
 | |
| void sqliteAttach(Parse*, Token*, Token*, Token*);
 | |
| void sqliteDetach(Parse*, Token*);
 | |
| int sqliteBtreeFactory(const sqlite *db, const char *zFilename,
 | |
|                        int mode, int nPg, Btree **ppBtree);
 | |
| int sqliteFixInit(DbFixer*, Parse*, int, const char*, const Token*);
 | |
| int sqliteFixSrcList(DbFixer*, SrcList*);
 | |
| int sqliteFixSelect(DbFixer*, Select*);
 | |
| int sqliteFixExpr(DbFixer*, Expr*);
 | |
| int sqliteFixExprList(DbFixer*, ExprList*);
 | |
| int sqliteFixTriggerStep(DbFixer*, TriggerStep*);
 | |
| double sqliteAtoF(const char *z, const char **);
 | |
| char *sqlite_snprintf(int,char*,const char*,...);
 | |
| int sqliteFitsIn32Bits(const char *);
 |