Alessandro Bonazzi 5c7aa8c1c0 Patch level : 12.0 no-patch
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Aggiunta documentazione di sqlite 3
2020-11-29 00:32:36 +01:00

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<a href="intro.html"><h2>SQLite C Interface</h2></a>
<h2>Serialize a database</h2>
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<blockquote><pre>
unsigned char *sqlite3_serialize(
sqlite3 *db, /* The database connection */
const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
);
</pre></blockquote>
<p>
The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
that is a serialization of the S database on <a href="../c3ref/sqlite3.html">database connection</a> D.
If P is not a NULL pointer, then the size of the database in bytes
is written into *P.</p>
<p>For an ordinary on-disk database file, the serialization is just a
copy of the disk file. For an in-memory database or a "TEMP" database,
the serialization is the same sequence of bytes which would be written
to disk if that database where backed up to disk.</p>
<p>The usual case is that sqlite3_serialize() copies the serialization of
the database into memory obtained from <a href="../c3ref/free.html">sqlite3_malloc64()</a> and returns
a pointer to that memory. The caller is responsible for freeing the
returned value to avoid a memory leak. However, if the F argument
contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
are made, and the sqlite3_serialize() function will return a pointer
to the contiguous memory representation of the database that SQLite
is currently using for that database, or NULL if the no such contiguous
memory representation of the database exists. A contiguous memory
representation of the database will usually only exist if there has
been a prior call to <a href="../c3ref/deserialize.html">sqlite3_deserialize(D,S,...)</a> with the same
values of D and S.
The size of the database is written into *P even if the
SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
of the database exists.</p>
<p>A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
allocation error occurs.</p>
<p>This interface is only available if SQLite is compiled with the
<a href="../compile.html#enable_deserialize">SQLITE_ENABLE_DESERIALIZE</a> option.
</p><p>See also lists of
<a href="objlist.html">Objects</a>,
<a href="constlist.html">Constants</a>, and
<a href="funclist.html">Functions</a>.</p>