1.Dd March 11, 2017 2.Dt SQLITE3CHANGEGROUP_ADD 3 3.Os 4.Sh NAME 5.Nm sqlite3changegroup_add 6.Nd Add A Changeset To A Changegroup 7.Sh SYNOPSIS 8.Ft int 9.Fo sqlite3changegroup_add 10.Fa "sqlite3_changegroup*" 11.Fa "int nData" 12.Fa "void *pData" 13.Fc 14.Sh DESCRIPTION 15Add all changes within the changeset (or patchset) in buffer pData 16(size nData bytes) to the changegroup. 17.Pp 18If the buffer contains a patchset, then all prior calls to this function 19on the same changegroup object must also have specified patchsets. 20Or, if the buffer contains a changeset, so must have the earlier calls 21to this function. 22Otherwise, SQLITE_ERROR is returned and no changes are added to the 23changegroup. 24.Pp 25Rows within the changeset and changegroup are identified by the values 26in their PRIMARY KEY columns. 27A change in the changeset is considered to apply to the same row as 28a change already present in the changegroup if the two rows have the 29same primary key. 30.Pp 31Changes to rows that do not already appear in the changegroup are simply 32copied into it. 33Or, if both the new changeset and the changegroup contain changes that 34apply to a single row, the final contents of the changegroup depends 35on the type of each change, as follows: 36.Pp 37<table border=1 style="margin-left:8ex;margin-right:8ex"> <tr><th style="white-space:pre">Existing 38Change </th> <th style="white-space:pre">New Change </th> <th>Output 39Change <tr><td>INSERT <td>INSERT <td> The new change is ignored. 40This case does not occur if the new changeset was recorded immediately 41after the changesets already added to the changegroup. 42<tr><td>INSERT <td>UPDATE <td> The INSERT change remains in the changegroup. 43The values in the INSERT change are modified as if the row was inserted 44by the existing change and then updated according to the new change. 45<tr><td>INSERT <td>DELETE <td> The existing INSERT is removed from 46the changegroup. 47The DELETE is not added. 48<tr><td>UPDATE <td>INSERT <td> The new change is ignored. 49This case does not occur if the new changeset was recorded immediately 50after the changesets already added to the changegroup. 51<tr><td>UPDATE <td>UPDATE <td> The existing UPDATE remains within the 52changegroup. 53It is amended so that the accompanying values are as if the row was 54updated once by the existing change and then again by the new change. 55<tr><td>UPDATE <td>DELETE <td> The existing UPDATE is replaced by the 56new DELETE within the changegroup. 57<tr><td>DELETE <td>INSERT <td> If one or more of the column values 58in the row inserted by the new change differ from those in the row 59deleted by the existing change, the existing DELETE is replaced by 60an UPDATE within the changegroup. 61Otherwise, if the inserted row is exactly the same as the deleted row, 62the existing DELETE is simply discarded. 63<tr><td>DELETE <td>UPDATE <td> The new change is ignored. 64This case does not occur if the new changeset was recorded immediately 65after the changesets already added to the changegroup. 66<tr><td>DELETE <td>DELETE <td> The new change is ignored. 67This case does not occur if the new changeset was recorded immediately 68after the changesets already added to the changegroup. 69</table> 70.Pp 71If the new changeset contains changes to a table that is already present 72in the changegroup, then the number of columns and the position of 73the primary key columns for the table must be consistent. 74If this is not the case, this function fails with SQLITE_SCHEMA. 75If the input changeset appears to be corrupt and the corruption is 76detected, SQLITE_CORRUPT is returned. 77Or, if an out-of-memory condition occurs during processing, this function 78returns SQLITE_NOMEM. 79In all cases, if an error occurs the final contents of the changegroup 80is undefined. 81.Pp 82If no error occurs, SQLITE_OK is returned. 83