.Dd December 19, 2018
.Dt SQLITE3CHANGEGROUP_OUTPUT 3
.Os
.Sh NAME
.Nm sqlite3changegroup_output
.Nd Obtain A Composite Changeset From A Changegroup
.Sh SYNOPSIS
.Ft int 
.Fo sqlite3changegroup_output
.Fa "sqlite3_changegroup*"
.Fa "int *pnData"
.Fa "void **ppData                   "
.Fc
.Sh DESCRIPTION
Obtain a buffer containing a changeset (or patchset) representing the
current contents of the changegroup.
If the inputs to the changegroup were themselves changesets, the output
is a changeset.
Or, if the inputs were patchsets, the output is also a patchset.
.Pp
As with the output of the sqlite3session_changeset() and sqlite3session_patchset()
functions, all changes related to a single table are grouped together
in the output of this function.
Tables appear in the same order as for the very first changeset added
to the changegroup.
If the second or subsequent changesets added to the changegroup contain
changes for tables that do not appear in the first changeset, they
are appended onto the end of the output changeset, again in the order
in which they are first encountered.
.Pp
If an error occurs, an SQLite error code is returned and the output
variables (*pnData) and (*ppData) are set to 0.
Otherwise, SQLITE_OK is returned and the output variables are set to
the size of and a pointer to the output buffer, respectively.
In this case it is the responsibility of the caller to eventually free
the buffer using a call to sqlite3_free().