SQLite

  sqlite3session S db main
  S attach t1
  execsql { INSERT INTO t1 VALUES(1, 'Sukhothai') }
  execsql { INSERT INTO t1 VALUES(2, 'Ayutthaya') }
  execsql { INSERT INTO t1 VALUES(3, 'Thonburi') }
} {}
do_changeset_test 2.1.2 S {
  {INSERT t1 0 X. {} {i 1 t Sukhothai}}
  {INSERT t1 0 X. {} {i 2 t Ayutthaya}}
  {INSERT t1 0 X. {} {i 3 t Thonburi}}
}
do_changeset_invert_test 2.1.3 S {
  {DELETE t1 0 X. {i 1 t Sukhothai} {}}
  {DELETE t1 0 X. {i 2 t Ayutthaya} {}}
  {DELETE t1 0 X. {i 3 t Thonburi} {}}
}
do_test 2.1.4 { S delete } {}

do_test 2.2.1 {
  sqlite3session S db main
  S attach t1
  execsql { DELETE FROM t1 WHERE 1 }
} {}
do_changeset_test 2.2.2 S {
  {DELETE t1 0 X. {i 1 t Sukhothai} {}}
  {DELETE t1 0 X. {i 2 t Ayutthaya} {}}
  {DELETE t1 0 X. {i 3 t Thonburi} {}}
}
do_changeset_invert_test 2.2.3 S {
  {INSERT t1 0 X. {} {i 1 t Sukhothai}}
  {INSERT t1 0 X. {} {i 2 t Ayutthaya}}
  {INSERT t1 0 X. {} {i 3 t Thonburi}}
}
do_test 2.2.4 { S delete } {}

do_test 2.3.1 {
  execsql { DELETE FROM t1 }
  sqlite3session S db main
  execsql { INSERT INTO t1 VALUES(1, 'Sukhothai') }
  execsql { INSERT INTO t1 VALUES(2, 'Ayutthaya') }
  execsql { INSERT INTO t1 VALUES(3, 'Thonburi') }
  S attach t1
  execsql { 
    UPDATE t1 SET x = 10 WHERE x = 1;
    UPDATE t1 SET y = 'Surin' WHERE x = 2;
    UPDATE t1 SET x = 20, y = 'Thapae' WHERE x = 3;
  }
} {}

do_changeset_test 2.3.2 S {
  {INSERT t1 0 X. {} {i 10 t Sukhothai}} 
  {DELETE t1 0 X. {i 1 t Sukhothai} {}} 
  {UPDATE t1 0 X. {i 2 t Ayutthaya} {{} {} t Surin}} 
  {DELETE t1 0 X. {i 3 t Thonburi} {}} 
  {INSERT t1 0 X. {} {i 20 t Thapae}} 
}

do_changeset_invert_test 2.3.3 S {
  {DELETE t1 0 X. {i 10 t Sukhothai} {}} 
  {INSERT t1 0 X. {} {i 1 t Sukhothai}} 
  {UPDATE t1 0 X. {{} {} t Surin} {i 2 t Ayutthaya}} 
  {INSERT t1 0 X. {} {i 3 t Thonburi}} 
  {DELETE t1 0 X. {i 20 t Thapae} {}}
}
do_test 2.3.4 { S delete } {}

do_test 2.4.1 {
  sqlite3session S db main
  S attach t1
  execsql { INSERT INTO t1 VALUES(100, 'Bangkok') }

  CREATE TABLE t1(a PRIMARY KEY, b);
  INSERT INTO t1 VALUES('i', 'one');
}
do_iterator_test 1.1 t1 {
  DELETE FROM t1 WHERE a = 'i';
  INSERT INTO t1 VALUES('ii', 'two');
} {
  {DELETE t1 0 X. {t i t one} {}} 
  {INSERT t1 0 X. {} {t ii t two}}
}
do_iterator_test 1.2 t1 {
  INSERT INTO t1 VALUES(1.5, 99.9)
} {
  {INSERT t1 0 X. {} {f 1.5 f 99.9}}
}


# Execute each of the following blocks of SQL on database [db1]. Collect
# changes using a session object. Apply the resulting changeset to
# database [db2]. Then check that the contents of the two databases are
# identical.

foreach {tn sql changeset} {
  1 {
    INSERT INTO t1 VALUES(123);
    INSERT INTO t1 VALUES(NULL);
    INSERT INTO t1 VALUES(456);
  } {
    {INSERT t1 0 X {} {i 456}} 
    {INSERT t1 0 X {} {i 123}}
  }

  2 {
    UPDATE t1 SET a = NULL;
  } {
    {DELETE t1 0 X {i 456} {}}
    {DELETE t1 0 X {i 123} {}}
  }

  3 { DELETE FROM t1 } { }

  4 { 
    INSERT INTO t3 VALUES(NULL, NULL)
  } {
    {INSERT t3 0 .X {} {n {} i 1}} 
  }

  5 { INSERT INTO t2 VALUES(1, 2, NULL) }    { }
  6 { INSERT INTO t2 VALUES(1, NULL, 3) }    { }
  7 { INSERT INTO t2 VALUES(1, NULL, NULL) } { }
  8 { INSERT INTO t2 VALUES(1, 2, 3) }    { {INSERT t2 0 .XX {} {i 1 i 2 i 3}} }
  9 { DELETE FROM t2 WHERE 1 }            { {DELETE t2 0 .XX {i 1 i 2 i 3} {}} }

} {
  do_iterator_test 4.$tn {t1 t2 t3} $sql $changeset
}


#-------------------------------------------------------------------------
# Test that if NULL is passed to sqlite3session_attach(), all database
# tables are attached to the session object.
#
test_reset
do_execsql_test 5.0 {
  CREATE TABLE t1(a PRIMARY KEY);
  CREATE TABLE t2(x, y PRIMARY KEY);
}

foreach {tn sql changeset} {
  1 { INSERT INTO t1 VALUES(35) }     { {INSERT t1 0 X {} {i 35}} }
  2 { INSERT INTO t2 VALUES(36, 37) } { {INSERT t2 0 .X {} {i 36 i 37}} }
  3 { 
    DELETE FROM t1 WHERE 1;
    UPDATE t2 SET x = 34;
  } { 
    {UPDATE t2 0 .X {i 36 i 37} {i 34 {} {}}}
    {DELETE t1 0 X {i 35} {}}
  }
} {
  do_iterator_test 5.$tn * $sql $changeset
}

#-------------------------------------------------------------------------
# The next block of tests verify that the "indirect" flag is set 

do_iterator_test 6.1.1 * {
  INSERT INTO t1 VALUES(1, 'one', 'i');
  SELECT indirect(1);
  INSERT INTO t1 VALUES(2, 'two', 'ii');
  SELECT indirect(0);
  INSERT INTO t1 VALUES(3, 'three', 'iii');
} {
  {INSERT t1 0 X.. {} {i 1 t one t i}}
  {INSERT t1 1 X.. {} {i 2 t two t ii}}
  {INSERT t1 0 X.. {} {i 3 t three t iii}}
}

do_iterator_test 6.1.2 * {
  SELECT indirect(1);
  UPDATE t1 SET c = 'I' WHERE a = 1;
  SELECT indirect(0);
} {
  {UPDATE t1 1 X.. {i 1 {} {} t i} {{} {} {} {} t I}}
}
do_iterator_test 6.1.3 * {
  SELECT indirect(1);
  UPDATE t1 SET c = '.' WHERE a = 1;
  SELECT indirect(0);
  UPDATE t1 SET c = 'o' WHERE a = 1;
} {
  {UPDATE t1 0 X.. {i 1 {} {} t I} {{} {} {} {} t o}}
}
do_iterator_test 6.1.4 * {
  SELECT indirect(0);
  UPDATE t1 SET c = 'x' WHERE a = 1;
  SELECT indirect(1);
  UPDATE t1 SET c = 'i' WHERE a = 1;
} {
  {UPDATE t1 0 X.. {i 1 {} {} t o} {{} {} {} {} t i}}
}
do_iterator_test 6.1.4 * {
  SELECT indirect(1);
  UPDATE t1 SET c = 'y' WHERE a = 1;
  SELECT indirect(1);
  UPDATE t1 SET c = 'I' WHERE a = 1;
} {
  {UPDATE t1 1 X.. {i 1 {} {} t i} {{} {} {} {} t I}}
}

do_iterator_test 6.1.5 * {
  INSERT INTO t2 VALUES(1, 'x');
} {
  {INSERT t2 0 X. {} {i 1 t x}}
  {INSERT t2 1 X. {} {i 2 n {}}}
}

do_iterator_test 6.1.6 * {
  SELECT indirect(1);
  INSERT INTO t2 VALUES(3, 'x');
  SELECT indirect(0);
  UPDATE t2 SET y = 'y' WHERE x>2;
} {
  {INSERT t2 0 X. {} {i 3 t y}}
  {INSERT t2 0 X. {} {i 4 t y}}
}

do_iterator_test 6.1.7 * {
  SELECT indirect(1);
  DELETE FROM t2 WHERE x = 4;
  SELECT indirect(0);
  INSERT INTO t2 VALUES(4, 'new');
} {
  {UPDATE t2 0 X. {i 4 t y} {{} {} t new}}
}

finish_test

  set {} {}
} -test {
  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
  if {$testrc==0} {
    set x [list]
    sqlite3session_foreach c $::inverse { lappend x $c }
    foreach c {
        {DELETE t1 0 .X {t xxx t yyy} {}} 
        {INSERT t1 0 .X {} {t string i 1}} 
        {UPDATE t1 0 .X {i 20 {} {}} {i 4 i 2}}
    } { lappend y $c }
    if {$x != $y} { error "changeset no good" }
  }
}

finish_test

  u8 *pNext;                      /* Pointer to next change within aChangeset */
  int rc;                         /* Iterator error code */
  sqlite3_stmt *pConflict;        /* Points to conflicting row, if any */
  char *zTab;                     /* Current table */
  int nCol;                       /* Number of columns in zTab */
  int op;                         /* Current operation */
  int bIndirect;                  /* True if current change was indirect */
  u8 *abPK;                       /* Primary key array */
  sqlite3_value **apValue;        /* old.* and new.* values */
};

/*
** Each session object maintains a set of the following structures, one
** for each table the session object is monitoring. The structures are
** stored in a linked list starting at sqlite3_session.pTable.

      sqlite3_stmt *pSel = 0;     /* SELECT statement to query table pTab */
      int nRewind = buf.nBuf;     /* Initial size of write buffer */
      int nNoop;                  /* Size of buffer after writing tbl header */

      /* Write a table header */
      sessionAppendByte(&buf, 'T', &rc);
      sessionAppendVarint(&buf, nCol, &rc);
      sessionAppendBlob(&buf, pTab->abPK, nCol, &rc);
      sessionAppendBlob(&buf, (u8 *)zName, strlen(zName)+1, &rc);

      /* Build and compile a statement to execute: */
      if( rc==SQLITE_OK ){
        rc = sessionSelectStmt(
            db, pSession->zDb, zName, nCol, pTab->azCol, abPK, &pSel);
      }

  }
  aChange = p->pNext;

  c = *(aChange++);
  if( c=='T' ){
    int nByte;                    /* Bytes to allocate for apValue */
    aChange += sessionVarintGet(aChange, &p->nCol);
    p->abPK = (u8 *)aChange;
    aChange += p->nCol;
    p->zTab = (char *)aChange;
    aChange += (strlen((char *)aChange) + 1);
    p->op = *(aChange++);
    p->bIndirect = *(aChange++);
    sqlite3_free(p->apValue);
    nByte = sizeof(sqlite3_value *) * p->nCol * 2;
    p->apValue = (sqlite3_value **)sqlite3_malloc(nByte);

  }

  p->pNext = aChange;
  return SQLITE_ROW;
}

/*
** The following function extracts information on the current change
** from a changeset iterator. They may only be called after changeset_next()
** has returned SQLITE_ROW.
*/
int sqlite3changeset_op(
  sqlite3_changeset_iter *pIter,  /* Iterator handle */
  const char **pzTab,             /* OUT: Pointer to table name */
  int *pnCol,                     /* OUT: Number of columns in table */
  int *pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */
  int *pbIndirect                 /* OUT: True if change is indirect */
){
  *pOp = pIter->op;
  *pnCol = pIter->nCol;
  *pzTab = pIter->zTab;
  if( pbIndirect ) *pbIndirect = pIter->bIndirect;
  return SQLITE_OK;
}

int sqlite3changeset_pk(
  sqlite3_changeset_iter *pIter,  /* Iterator object */
  unsigned char **pabPK,          /* OUT: Array of boolean - true for PK cols */
  int *pnCol                      /* OUT: Number of entries in output array */
){
  *pabPK = pIter->abPK;
  if( pnCol ) *pnCol = pIter->nCol;
  return SQLITE_OK;
}

/*
** This function may only be called while the iterator is pointing to an
** SQLITE_UPDATE or SQLITE_DELETE change (see sqlite3changeset_op()).
** Otherwise, SQLITE_MISUSE is returned.
**
** It sets *ppValue to point to an sqlite3_value structure containing the

  aIn = (u8 *)pChangeset;

  i = 0;
  while( i<nChangeset ){
    u8 eType = aIn[i];
    switch( eType ){
      case 'T': {
        /* A 'table' record consists of:
        **
        **   * A constant 'T' character,
        **   * Number of columns in said table (a varint),
        **   * An array of nCol bytes (abPK),
        **   * A nul-terminated table name.
        */
        int nByte = 1 + sessionVarintGet(&aIn[i+1], &nCol);
        nByte += nCol;
        nByte += 1 + strlen((char *)&aIn[i+nByte]);
        memcpy(&aOut[i], &aIn[i], nByte);
        i += nByte;
        break;
      }

      case SQLITE_INSERT:

int sqlite3changeset_op(
  sqlite3_changeset_iter *pIter,  /* Iterator object */
  const char **pzTab,             /* OUT: Pointer to table name */
  int *pnCol,                     /* OUT: Number of columns in table */
  int *pOp,                       /* OUT: SQLITE_INSERT, DELETE or UPDATE */
  int *pbIndirect                 /* OUT: True for an 'indirect' change */
);

/*
** CAPI3REF: Obtain The Primary Key Definition Of A Table
**
** For each modified table, a changeset includes the following:
**
** <ul>
**   <li> The number of columns in the table, and
**   <li> Which of those columns make up the tables PRIMARY KEY.
** </ul>
**
** This function is used to find which columns comprise the PRIMARY KEY of
** the table modified by the change that iterator pIter currently points to.
** If successful, *pabPK is set to point to an array of nCol entries, where
** nCol is the number of columns in the table. Elements of *pabPK are set to
** 0x01 if the corresponding column is part of the tables primary key, or
** 0x00 if it is not.
**
** If argumet pnCol is not NULL, then *pnCol is set to the number of columns
** in the table.
**
** If this function is called when the iterator does not point to a valid
** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
** SQLITE_OK is returned and the output variables populated as described
** above.
*/
int sqlite3changeset_pk(
  sqlite3_changeset_iter *pIter,  /* Iterator object */
  unsigned char **pabPK,          /* OUT: Array of boolean - true for PK cols */
  int *pnCol                      /* OUT: Number of entries in output array */
);

/*
** CAPI3REF: Obtain old.* Values From A Changeset Iterator
**
** The pIter argument passed to this function may either be an iterator
** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
** created by [sqlite3changeset_start()]. In the latter case, the most recent

    int nCol;                     /* Number of columns in table */
    int op;                       /* SQLITE_INSERT, UPDATE or DELETE */
    const char *zTab;             /* Name of table change applies to */
    Tcl_Obj *pVar;                /* Tcl value to set $VARNAME to */
    Tcl_Obj *pOld;                /* Vector of old.* values */
    Tcl_Obj *pNew;                /* Vector of new.* values */
    int bIndirect;

    char *zPK;
    unsigned char *abPK;
    int i;

    sqlite3changeset_op(pIter, &zTab, &nCol, &op, &bIndirect);
    pVar = Tcl_NewObj();
    Tcl_ListObjAppendElement(0, pVar, Tcl_NewStringObj(
          op==SQLITE_INSERT ? "INSERT" :
          op==SQLITE_UPDATE ? "UPDATE" : 
          "DELETE", -1
    ));

    Tcl_ListObjAppendElement(0, pVar, Tcl_NewStringObj(zTab, -1));
    Tcl_ListObjAppendElement(0, pVar, Tcl_NewBooleanObj(bIndirect));

    zPK = ckalloc(nCol+1);
    memset(zPK, 0, nCol+1);
    sqlite3changeset_pk(pIter, &abPK, 0);
    for(i=0; i<nCol; i++){
      zPK[i] = (abPK[i] ? 'X' : '.');
    }
    Tcl_ListObjAppendElement(0, pVar, Tcl_NewStringObj(zPK, -1));
    ckfree(zPK);

    pOld = Tcl_NewObj();
    if( op!=SQLITE_INSERT ){
      int i;
      for(i=0; i<nCol; i++){
        sqlite3_value *pVal;
        sqlite3changeset_old(pIter, i, &pVal);