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## Session Module C Interface

## Generate A Patchset From A Session Object

>     int sqlite3session_patchset(
>       sqlite3_session *pSession,      /* Session object */
>       int *pnPatchset,                /* OUT: Size of buffer at *ppPatchset */
>       void **ppPatchset               /* OUT: Buffer containing patchset */
>     );

The differences between a patchset and a changeset are that:

- DELETE records consist of the primary key fields only. The original values of other fields are omitted.
- The original values of any modified fields are omitted from UPDATE records.

A patchset blob may be used with up to date versions of all sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, attempting to use a patchset blob with old versions of the sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.

Because the non-primary key "old.*" fields are omitted, no SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset is passed to the sqlite3changeset_apply() API. Other conflict types work in the same way as for changesets.

Changes within a patchset are ordered in the same way as for changesets generated by the sqlite3session_changeset() function (i.e. all changes for a single table are grouped together, tables appear in the order in which they were attached to the session object).

See also lists of Objects, Constants, and Functions.