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SQLITE3SESSION_DIFF(3)     Library Functions Manual     SQLITE3SESSION_DIFF(3)

NAME
     sqlite3session_diff - load the difference between tables into a session

SYNOPSIS
     #include <sqlite3.h>

     int
     sqlite3session_diff(sqlite3_session *pSession, const char *zFromDb,
         const char *zTbl, char **pzErrMsg);

DESCRIPTION
     If it is not already attached to the session object passed as the first
     argument, this function attaches table zTbl in the same manner as the
     sqlite3session_attach() function.  If zTbl does not exist, or if it does
     not have a primary key, this function is a no-op (but does not return an
     error).

     Argument zFromDb must be the name of a database ("main", "temp" etc.)
     attached to the same database handle as the session object that contains
     a table compatible with the table attached to the session by this
     function.  A table is considered compatible if it:

     ⊕   Has the same name,

     ⊕   Has the same set of columns declared in the same order, and

     ⊕   Has the same PRIMARY KEY definition.

     If the tables are not compatible, SQLITE_SCHEMA is returned.  If the
     tables are compatible but do not have any PRIMARY KEY columns, it is not
     an error but no changes are added to the session object.  As with other
     session APIs, tables without PRIMARY KEYs are simply ignored.

     This function adds a set of changes to the session object that could be
     used to update the table in database zFrom (call this the "from-table")
     so that its content is the same as the table attached to the session
     object (call this the "to-table").  Specifically:

     ⊕   For each row (primary key) that exists in the to-table but not in the
         from-table, an INSERT record is added to the session object.

     ⊕   For each row (primary key) that exists in the to-table but not in the
         from-table, a DELETE record is added to the session object.

     ⊕   For each row (primary key) that exists in both tables, but features
         different non-PK values in each, an UPDATE record is added to the
         session.

     To clarify, if this function is called and then a changeset constructed
     using sqlite3session_changeset(), then after applying that changeset to
     database zFrom the contents of the two compatible tables would be
     identical.

     It an error if database zFrom does not exist or does not contain the
     required compatible table.

     If the operation is successful, SQLITE_OK is returned.  Otherwise, an
     SQLite error code.  In this case, if argument pzErrMsg is not NULL,
     *pzErrMsg may be set to point to a buffer containing an English language
     error message.  It is the responsibility of the caller to free this
     buffer using sqlite3_free().

IMPLEMENTATION NOTES
     These declarations were extracted from the interface documentation at
     line 11181.

     SQLITE_API int sqlite3session_diff(
       sqlite3_session *pSession,
       const char *zFromDb,
       const char *zTbl,
       char **pzErrMsg
     );

SEE ALSO
     sqlite3session_attach(3), sqlite3session_changeset(3)

NetBSD 10.99                    August 24, 2023                   NetBSD 10.99