int sqlite3changegroup_new(sqlite3_changegroup **pp);
An sqlite3_changegroup object is used to combine two or more changesets (or patchsets) into a single changeset (or patchset). A single changegroup object may combine changesets or patchsets, but not both. The output is always in the same format as the input.
If successful, this function returns SQLITE_OK and populates (*pp) with a pointer to a new sqlite3_changegroup object before returning. The caller should eventually free the returned object using a call to sqlite3changegroup_delete(). If an error occurs, an SQLite error code (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
The usual usage pattern for an sqlite3_changegroup object is as follows:
Any number of calls to add() and output() may be made between the calls to new() and delete(), and in any order.
As well as the regular sqlite3changegroup_add() and sqlite3changegroup_output() functions, also available are the streaming versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().