if {![info exists O($key)]} {error "no such option: $key"}
  }
  array set O $args

  sqlite3session S db main
  foreach t $O(-tables) { S attach $t }
  execsql $O(-sql)

  set ::xConflict [list]
  sqlite3changeset_apply db2 [S changeset] xConflict

  set conflicts [list]
  foreach c $O(-conflicts) {
    lappend conflicts $c
  }

    if {![info exists O($key)]} {error "no such option: $key"}
  }
  array set O $args

  sqlite3session S db main
  foreach t $O(-tables) { S attach $t }
  execsql $O(-sql)

  set ::xConflict [list]
  sqlite3changeset_apply db2 [S changeset] xConflict

  set conflicts [list]
  foreach c $O(-conflicts) {
    lappend conflicts $c
  }

  15 {
    INSERT INTO %T1% VALUES(1, 1);
    INSERT INTO %T1% SELECT a+2, b+2 FROM %T1%;
    INSERT INTO %T1% SELECT a+4, b+4 FROM %T1%;
    INSERT INTO %T1% SELECT a+8, b+8 FROM %T1%;
    INSERT INTO %T1% SELECT a+256, b+256 FROM %T1%;
  }







}

test_reset
do_common_sql {
  CREATE TABLE t1(a PRIMARY KEY, b);
  CREATE TABLE t2(a, b INTEGER PRIMARY KEY);
  CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b));

}

foreach {tn sql} [string map {%T1% t1 %T2% t2 %T3% t3} $set_of_tests] {
  do_then_apply_sql $sql
  do_test 2.$tn { compare_db db db2 } {}
}

# The following block of tests is similar to the last, except that the
# session object is recording changes made to an attached database. The
# main database contains a table of the same name as the table being
................................................................................
    CREATE TABLE t1(a, b PRIMARY KEY);
    CREATE TABLE t2(x, y, z);
    CREATE TABLE t3(a);

    CREATE TABLE aux.t1(a PRIMARY KEY, b);
    CREATE TABLE aux.t2(a, b INTEGER PRIMARY KEY);
    CREATE TABLE aux.t3(a, b, c, PRIMARY KEY(a, b));

  }
  execsql {
    CREATE TABLE t1(a PRIMARY KEY, b);
    CREATE TABLE t2(a, b INTEGER PRIMARY KEY);
    CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b));

  } db2
} {}

proc xTrace {args} { puts $args }

foreach {tn sql} [
  string map {%T1% aux.t1 %T2% aux.t2 %T3% aux.t3} $set_of_tests
] {
  do_then_apply_sql $sql aux
  do_test 3.$tn { compare_db db3 db2 } {}
}
catch {db3 close}


#-------------------------------------------------------------------------
# The following tests verify that NULL values in primary key columns are
# handled correctly by the session module.

  15 {
    INSERT INTO %T1% VALUES(1, 1);
    INSERT INTO %T1% SELECT a+2, b+2 FROM %T1%;
    INSERT INTO %T1% SELECT a+4, b+4 FROM %T1%;
    INSERT INTO %T1% SELECT a+8, b+8 FROM %T1%;
    INSERT INTO %T1% SELECT a+256, b+256 FROM %T1%;
  }

  16 {
    INSERT INTO %T4% VALUES('abc', 'def');
    INSERT INTO %T4% VALUES('def', 'abc');
  }
  17 { UPDATE %T4% SET b = 1 }
  18 { DELETE FROM %T4% WHERE 1 }
}

test_reset
do_common_sql {
  CREATE TABLE t1(a PRIMARY KEY, b);
  CREATE TABLE t2(a, b INTEGER PRIMARY KEY);
  CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b));
  CREATE TABLE t4(a, b, PRIMARY KEY(b, a));
}

foreach {tn sql} [string map {%T1% t1 %T2% t2 %T3% t3 %T4% t4} $set_of_tests] {
  do_then_apply_sql $sql
  do_test 2.$tn { compare_db db db2 } {}
}

# The following block of tests is similar to the last, except that the
# session object is recording changes made to an attached database. The
# main database contains a table of the same name as the table being
................................................................................
    CREATE TABLE t1(a, b PRIMARY KEY);
    CREATE TABLE t2(x, y, z);
    CREATE TABLE t3(a);

    CREATE TABLE aux.t1(a PRIMARY KEY, b);
    CREATE TABLE aux.t2(a, b INTEGER PRIMARY KEY);
    CREATE TABLE aux.t3(a, b, c, PRIMARY KEY(a, b));
    CREATE TABLE aux.t4(a, b, PRIMARY KEY(b, a));
  }
  execsql {
    CREATE TABLE t1(a PRIMARY KEY, b);
    CREATE TABLE t2(a, b INTEGER PRIMARY KEY);
    CREATE TABLE t3(a, b, c, PRIMARY KEY(a, b));
    CREATE TABLE t4(a, b, PRIMARY KEY(b, a));
  } db2
} {}

proc xTrace {args} { puts $args }

foreach {tn sql} [
  string map {%T1% aux.t1 %T2% aux.t2 %T3% aux.t3 %T4% aux.t4} $set_of_tests
] {
  do_then_apply_sql $sql aux
  do_test 3.$tn { compare_db db2 db3 } {}
}
catch {db3 close}


#-------------------------------------------------------------------------
# The following tests verify that NULL values in primary key columns are
# handled correctly by the session module.

#
proc compare_db {db1 db2} {

  set sql {SELECT name FROM sqlite_master WHERE type = 'table' ORDER BY name}
  set lot1 [$db1 eval $sql]
  set lot2 [$db2 eval $sql]




  if {$lot1 != $lot2} { error "databases contain different tables" }


  foreach tbl $lot1 {
    set col1 [list]
    set col2 [list]

    $db1 eval "PRAGMA table_info = $tbl" { lappend col1 $name }
    $db2 eval "PRAGMA table_info = $tbl" { lappend col2 $name }

#
proc compare_db {db1 db2} {

  set sql {SELECT name FROM sqlite_master WHERE type = 'table' ORDER BY name}
  set lot1 [$db1 eval $sql]
  set lot2 [$db2 eval $sql]

  if {$lot1 != $lot2} { 
    puts $lot1
    puts $lot2
    error "databases contain different tables" 
  }

  foreach tbl $lot1 {
    set col1 [list]
    set col2 [list]

    $db1 eval "PRAGMA table_info = $tbl" { lappend col1 $name }
    $db2 eval "PRAGMA table_info = $tbl" { lappend col2 $name }

  if {$testrc==0} { 
    sqlite3changeset_apply db2 [S changeset] xConflict
    compare_db db db2 
  }
  catch { S delete }
  faultsim_integrity_check
}





















































finish_test

  if {$testrc==0} { 
    sqlite3changeset_apply db2 [S changeset] xConflict
    compare_db db db2 
  }
  catch { S delete }
  faultsim_integrity_check
}

catch { db close }
catch { db2 close }
forcedelete test.db2 test.db
sqlite3 db2 test.db2
sqlite3 db test.db

proc xConflict {op tbl type args} {
  if { $type=="CONFLICT" || $type=="DATA" } {
    return "REPLACE"
  }
  return "OMIT"
}

do_test 3.0 {
  execsql {
    PRAGMA encoding = 'utf16';
    CREATE TABLE t1(a PRIMARY KEY, b);
    INSERT INTO t1 VALUES(5, 32);
  }
  execsql {
    PRAGMA encoding = 'utf16';
    CREATE TABLE t1(a PRIMARY KEY, b NOT NULL);
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t1 VALUES(2, 4);
    INSERT INTO t1 VALUES(4, 16);
  } db2
} {}

faultsim_save_and_close
db2 close

do_faultsim_test pagerfault-3 -faults oom-transient -prep {
  catch {db2 close}
  catch {db close}
  faultsim_restore_and_reopen
  sqlite3 db2 test.db2
  sqlite3session S db main
  S attach t1
  execsql {
    INSERT INTO t1 VALUES(1, 45);
    INSERT INTO t1 VALUES(2, 55);
    INSERT INTO t1 VALUES(3, 55);
    UPDATE t1 SET a = 4 WHERE a = 5;
  }
} -body {
  sqlite3changeset_apply db2 [S changeset] xConflict
} -test {
  catch { S delete }
  faultsim_test_result {0 {}} {1 SQLITE_NOMEM}
  if {$testrc==0} { compare_db db db2 }
}

finish_test

  sqlite3_stmt *pStmt;
  int rc;
  int nByte;
  int nDbCol = 0;
  int nThis;
  int i;
  u8 *pAlloc;
  u8 *pFree = 0;
  char **azCol;
  u8 *abPK;

  assert( pazCol || pabPK );

  nThis = strlen(zThis);
  zPragma = sqlite3_mprintf("PRAGMA '%q'.table_info('%q')", zDb, zThis);
  if( !zPragma ) return SQLITE_NOMEM;

  rc = sqlite3_prepare_v2(db, zPragma, -1, &pStmt, 0);
  sqlite3_free(zPragma);
................................................................................
    nByte += nDbCol * (sizeof(const char *) + sizeof(u8) + 1);
    pAlloc = sqlite3_malloc(nByte);
    if( pAlloc==0 ){
      rc = SQLITE_NOMEM;
    }
  }
  if( rc==SQLITE_OK ){
    pFree = pAlloc;
    if( pazCol ){
      azCol = (char **)pAlloc;
      pAlloc = (u8 *)&azCol[nCol];
    }
    if( pabPK ){
      abPK = (u8 *)pAlloc;
      pAlloc = &abPK[nCol];
    }
    if( pzTab ){
      memcpy(pAlloc, zThis, nThis+1);
      *pzTab = (char *)pAlloc;
      pAlloc += nThis+1;
    }
  
    i = 0;
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
      int nName = sqlite3_column_bytes(pStmt, 1);
      const unsigned char *zName = sqlite3_column_text(pStmt, 1);
      if( zName==0 ) break;
      if( pazCol ){
        memcpy(pAlloc, zName, nName+1);
        azCol[i] = (char *)pAlloc;
        pAlloc += nName+1;
      }
      if( pabPK ) abPK[i] = sqlite3_column_int(pStmt, 5);
      i++;
    }
    rc = sqlite3_reset(pStmt);
  
  }

  /* If successful, populate the output variables. Otherwise, zero them and
  ** free any allocation made. An error code will be returned in this case.
  */
  if( rc==SQLITE_OK ){
    if( pazCol ) *pazCol = (const char **)azCol;
    if( pabPK ) *pabPK = abPK;
  }else{
    if( pazCol ) *pazCol = 0;
    if( pabPK ) *pabPK = 0;
    if( pzTab ) *pzTab = 0;
    sqlite3_free(pFree);
  }
  sqlite3_finalize(pStmt);
  return rc;
}

/*
** This function is only called from within a pre-update handler for a
................................................................................
** Formulate a statement to DELETE a row from database db. Assuming a table
** structure like this:
**
**     CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));
**
** The DELETE statement looks like this:
**
**     DELETE FROM x WHERE a = :1 AND c = :3 AND :5 OR (b IS :2 AND d IS :4)
**
** Variable :5 (nCol+1) is a boolean. It should be set to 0 if we require
** matching b and d values, or 1 otherwise. The second case comes up if the
** conflict handler is invoked with NOTFOUND and returns CHANGESET_REPLACE.
**
** If successful, SQLITE_OK is returned and SessionApplyCtx.pDelete is left
** pointing to the prepared version of the SQL statement.
................................................................................

  if( rc==SQLITE_OK ){
    rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pInsert, 0);
  }
  sqlite3_free(buf.aBuf);
  return rc;
}




































/*
** SQL statement pSelect is as generated by the sessionSelectRow() function.
** This function binds the primary key values from the change that changeset
** iterator pIter points to to the SELECT and attempts to seek to the table
** entry. If a row is found, the SELECT statement left pointing at the row 
** and SQLITE_ROW is returned. Otherwise, if no row is found and no error
** has occured, the statement is reset and SQLITE_OK is returned. If an
** error occurs, an SQLite error code is returned.
**
** If the iterator currently points to an INSERT record, bind values from the
** new.* record to the SELECT statement. Or, if it points to a DELETE, bind
** values from the old.* record. If the changeset iterator points to an
** UPDATE, bind values from the new.* record, but use old.* values in place
** of any undefined new.* values.
*/
static int sessionSeekToRow(
  sqlite3 *db,                    /* Database handle */
  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
  u8 *abPK,                       /* Primary key flags array */
  sqlite3_stmt *pSelect           /* SELECT statement from sessionSelectRow() */
){
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Used to iterate through table columns */
  int nCol;                       /* Number of columns in table */
  int op;                         /* Changset operation (SQLITE_UPDATE etc.) */
  const char *zDummy;             /* Unused */

  sqlite3changeset_op(pIter, &zDummy, &nCol, &op);


  for(i=0; rc==SQLITE_OK && i<nCol; i++){
    if( abPK[i] ){
      sqlite3_value *pVal = 0;
      if( op!=SQLITE_DELETE ){
        rc = sqlite3changeset_new(pIter, i, &pVal);
      }
      if( pVal==0 ){
        rc = sqlite3changeset_old(pIter, i, &pVal);
      }
      if( rc==SQLITE_OK ){
        rc = sqlite3_bind_value(pSelect, i+1, pVal);
      }
    }
  }


  if( rc==SQLITE_OK ){
    rc = sqlite3_step(pSelect);
    if( rc!=SQLITE_ROW ) rc = sqlite3_reset(pSelect);
  }

  return rc;
................................................................................
  assert( SQLITE_CHANGESET_CONFLICT+1==SQLITE_CHANGESET_CONSTRAINT );
  assert( SQLITE_CHANGESET_DATA+1==SQLITE_CHANGESET_NOTFOUND );

  /* Bind the new.* PRIMARY KEY values to the SELECT statement. */
  if( pbReplace ){
    rc = sessionSeekToRow(p->db, pIter, p->abPK, p->pSelect);
  }else{
    rc = SQLITE_DONE;
  }

  if( rc==SQLITE_ROW ){
    /* There exists another row with the new.* primary key. */
    pIter->pConflict = p->pSelect;
    res = xConflict(pCtx, eType, pIter);
    pIter->pConflict = 0;
    rc = sqlite3_reset(p->pSelect);
  }else{
    /* No other row with the new.* primary key. */
    rc = sqlite3_reset(p->pSelect);
    if( rc==SQLITE_OK ){
      res = xConflict(pCtx, eType+1, pIter);
      if( res==SQLITE_CHANGESET_REPLACE ) rc = SQLITE_MISUSE;
    }
  }
................................................................................
  assert( p->pDelete && p->pUpdate && p->pInsert && p->pSelect );
  assert( p->azCol && p->abPK );
  assert( !pbReplace || *pbReplace==0 );

  sqlite3changeset_op(pIter, &zDummy, &nCol, &op);

  if( op==SQLITE_DELETE ){
    int i;

    /* Bind values to the DELETE statement. */
    for(i=0; rc==SQLITE_OK && i<nCol; i++){
      sqlite3_value *pVal;
      rc = sqlite3changeset_old(pIter, i, &pVal);
      if( rc==SQLITE_OK ){
        rc = sqlite3_bind_value(p->pDelete, i+1, pVal);
      }
    }

    if( rc==SQLITE_OK && sqlite3_bind_parameter_count(p->pDelete)>nCol ){
      rc = sqlite3_bind_int(p->pDelete, nCol+1, pbRetry==0);
    }
    if( rc!=SQLITE_OK ) return rc;

    sqlite3_step(p->pDelete);
    rc = sqlite3_reset(p->pDelete);
................................................................................
      ** Otherwise, if there is no primary key match, it is a NOTFOUND. */

      rc = sessionConflictHandler(
          SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry
      );

    }else if( rc==SQLITE_CONSTRAINT ){
      /* This may be a CONSTRAINT or CONFLICT error. It is a CONFLICT if
      ** the only problem is a duplicate PRIMARY KEY, or a CONSTRAINT 
      ** otherwise. */
      int bPKChange = 0;

      /* Check if the PK has been modified. */
      rc = SQLITE_OK;
      for(i=0; i<nCol && rc==SQLITE_OK; i++){
        if( p->abPK[i] ){
          sqlite3_value *pNew;
          rc = sqlite3changeset_new(pIter, i, &pNew);
          if( rc==SQLITE_OK && pNew ){
            bPKChange = 1;
            break;
          }
        }
      }

      rc = sessionConflictHandler(SQLITE_CHANGESET_CONFLICT, 
          p, pIter, xConflict, pCtx, (bPKChange ? pbReplace : 0)
      );
    }

  }else{
    int i;
    assert( op==SQLITE_INSERT );
    for(i=0; rc==SQLITE_OK && i<nCol; i++){
      sqlite3_value *pVal;
      rc = sqlite3changeset_new(pIter, i, &pVal);
      if( rc==SQLITE_OK ){
        rc = sqlite3_bind_value(p->pInsert, i+1, pVal);
      }
    }

    if( rc!=SQLITE_OK ) return rc;

    sqlite3_step(p->pInsert);
    rc = sqlite3_reset(p->pInsert);
    if( rc==SQLITE_CONSTRAINT && xConflict ){
      rc = sessionConflictHandler(
          SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, pbReplace
      );
    }
  }

  return rc;
................................................................................
    rc = sessionApplyOneOp(pIter, &sApply, xConflict, pCtx, &bReplace, &bRetry);

    if( rc==SQLITE_OK && bRetry ){
      rc = sessionApplyOneOp(pIter, &sApply, xConflict, pCtx, &bReplace, 0);
    }

    if( bReplace ){

      rc = sqlite3_exec(db, "SAVEPOINT replace_op", 0, 0, 0);
      if( rc==SQLITE_OK ){
        int i;
        for(i=0; i<sApply.nCol; i++){
          if( sApply.abPK[i] ){
            sqlite3_value *pVal;
            rc = sqlite3changeset_new(pIter, i, &pVal);
            if( rc==SQLITE_OK && pVal==0 ){
              rc = sqlite3changeset_old(pIter, i, &pVal);
            }
            if( rc==SQLITE_OK ){
              rc = sqlite3_bind_value(sApply.pDelete, i+1, pVal);
            }
          }
        }
        sqlite3_bind_int(sApply.pDelete, sApply.nCol+1, 1);
      }
      if( rc==SQLITE_OK ){
        sqlite3_step(sApply.pDelete);
        rc = sqlite3_reset(sApply.pDelete);
      }
      if( rc==SQLITE_OK ){

  sqlite3_stmt *pStmt;
  int rc;
  int nByte;
  int nDbCol = 0;
  int nThis;
  int i;
  u8 *pAlloc;

  char **azCol = 0;
  u8 *abPK;

  assert( pazCol && pabPK );

  nThis = strlen(zThis);
  zPragma = sqlite3_mprintf("PRAGMA '%q'.table_info('%q')", zDb, zThis);
  if( !zPragma ) return SQLITE_NOMEM;

  rc = sqlite3_prepare_v2(db, zPragma, -1, &pStmt, 0);
  sqlite3_free(zPragma);
................................................................................
    nByte += nDbCol * (sizeof(const char *) + sizeof(u8) + 1);
    pAlloc = sqlite3_malloc(nByte);
    if( pAlloc==0 ){
      rc = SQLITE_NOMEM;
    }
  }
  if( rc==SQLITE_OK ){


    azCol = (char **)pAlloc;
    pAlloc = (u8 *)&azCol[nCol];


    abPK = (u8 *)pAlloc;
    pAlloc = &abPK[nCol];

    if( pzTab ){
      memcpy(pAlloc, zThis, nThis+1);
      *pzTab = (char *)pAlloc;
      pAlloc += nThis+1;
    }
  
    i = 0;
    while( SQLITE_ROW==sqlite3_step(pStmt) ){
      int nName = sqlite3_column_bytes(pStmt, 1);
      const unsigned char *zName = sqlite3_column_text(pStmt, 1);
      if( zName==0 ) break;

      memcpy(pAlloc, zName, nName+1);
      azCol[i] = (char *)pAlloc;
      pAlloc += nName+1;

      abPK[i] = sqlite3_column_int(pStmt, 5);
      i++;
    }
    rc = sqlite3_reset(pStmt);
  
  }

  /* If successful, populate the output variables. Otherwise, zero them and
  ** free any allocation made. An error code will be returned in this case.
  */
  if( rc==SQLITE_OK ){
    *pazCol = (const char **)azCol;
    *pabPK = abPK;
  }else{
    *pazCol = 0;
    *pabPK = 0;
    if( pzTab ) *pzTab = 0;
    sqlite3_free(azCol);
  }
  sqlite3_finalize(pStmt);
  return rc;
}

/*
** This function is only called from within a pre-update handler for a
................................................................................
** Formulate a statement to DELETE a row from database db. Assuming a table
** structure like this:
**
**     CREATE TABLE x(a, b, c, d, PRIMARY KEY(a, c));
**
** The DELETE statement looks like this:
**
**     DELETE FROM x WHERE a = :1 AND c = :3 AND (:5 OR b IS :2 AND d IS :4)
**
** Variable :5 (nCol+1) is a boolean. It should be set to 0 if we require
** matching b and d values, or 1 otherwise. The second case comes up if the
** conflict handler is invoked with NOTFOUND and returns CHANGESET_REPLACE.
**
** If successful, SQLITE_OK is returned and SessionApplyCtx.pDelete is left
** pointing to the prepared version of the SQL statement.
................................................................................

  if( rc==SQLITE_OK ){
    rc = sqlite3_prepare_v2(db, (char *)buf.aBuf, buf.nBuf, &p->pInsert, 0);
  }
  sqlite3_free(buf.aBuf);
  return rc;
}

/*
** Iterator pIter must point to an SQLITE_INSERT entry. This function 
** transfers new.* values from the current iterator entry to statement
** pStmt. The table being inserted into has nCol columns.
**
** New.* value $i 0 from the iterator is bound to variable ($i+1) of 
** statement pStmt. If parameter abPK is NULL, all values from 0 to (nCol-1)
** are transfered to the statement. Otherwise, if abPK is not NULL, it points
** to an array nCol elements in size. In this case only those values for 
** which abPK[$i] is true are read from the iterator and bound to the 
** statement.
**
** An SQLite error code is returned if an error occurs. Otherwise, SQLITE_OK.
*/
static int sessionBindValues(
  sqlite3_changeset_iter *pIter,  /* Iterator to read values from */
  int(*xIterValue)(sqlite3_changeset_iter *, int, sqlite3_value **),
  int nCol,                       /* Number of columns */
  u8 *abPK,                       /* If not NULL, bind only if true */
  sqlite3_stmt *pStmt             /* Bind values to this statement */
){
  int i;
  int rc = SQLITE_OK;
  for(i=0; rc==SQLITE_OK && i<nCol; i++){
    if( !abPK || abPK[i] ){
      sqlite3_value *pVal;
      rc = xIterValue(pIter, i, &pVal);
      if( rc==SQLITE_OK ){
        rc = sqlite3_bind_value(pStmt, i+1, pVal);
      }
    }
  }
  return rc;
}

/*
** SQL statement pSelect is as generated by the sessionSelectRow() function.
** This function binds the primary key values from the change that changeset
** iterator pIter points to to the SELECT and attempts to seek to the table
** entry. If a row is found, the SELECT statement left pointing at the row 
** and SQLITE_ROW is returned. Otherwise, if no row is found and no error
** has occured, the statement is reset and SQLITE_OK is returned. If an
** error occurs, an SQLite error code is returned.
**
** If the iterator currently points to an INSERT record, bind values from the
** new.* record to the SELECT statement. Or, if it points to a DELETE or

** UPDATE, bind values from the old.* record. 

*/
static int sessionSeekToRow(
  sqlite3 *db,                    /* Database handle */
  sqlite3_changeset_iter *pIter,  /* Changeset iterator */
  u8 *abPK,                       /* Primary key flags array */
  sqlite3_stmt *pSelect           /* SELECT statement from sessionSelectRow() */
){
  int rc = SQLITE_OK;             /* Return code */

  int nCol;                       /* Number of columns in table */
  int op;                         /* Changset operation (SQLITE_UPDATE etc.) */
  const char *zDummy;             /* Unused */

  sqlite3changeset_op(pIter, &zDummy, &nCol, &op);

  rc = sessionBindValues(pIter, 
      op==SQLITE_INSERT ? sqlite3changeset_new : sqlite3changeset_old,
      nCol, abPK, pSelect












  );

  if( rc==SQLITE_OK ){
    rc = sqlite3_step(pSelect);
    if( rc!=SQLITE_ROW ) rc = sqlite3_reset(pSelect);
  }

  return rc;
................................................................................
  assert( SQLITE_CHANGESET_CONFLICT+1==SQLITE_CHANGESET_CONSTRAINT );
  assert( SQLITE_CHANGESET_DATA+1==SQLITE_CHANGESET_NOTFOUND );

  /* Bind the new.* PRIMARY KEY values to the SELECT statement. */
  if( pbReplace ){
    rc = sessionSeekToRow(p->db, pIter, p->abPK, p->pSelect);
  }else{
    rc = SQLITE_OK;
  }

  if( rc==SQLITE_ROW ){
    /* There exists another row with the new.* primary key. */
    pIter->pConflict = p->pSelect;
    res = xConflict(pCtx, eType, pIter);
    pIter->pConflict = 0;
    rc = sqlite3_reset(p->pSelect);
  }else if( rc==SQLITE_OK ){
    /* No other row with the new.* primary key. */
    rc = sqlite3_reset(p->pSelect);
    if( rc==SQLITE_OK ){
      res = xConflict(pCtx, eType+1, pIter);
      if( res==SQLITE_CHANGESET_REPLACE ) rc = SQLITE_MISUSE;
    }
  }
................................................................................
  assert( p->pDelete && p->pUpdate && p->pInsert && p->pSelect );
  assert( p->azCol && p->abPK );
  assert( !pbReplace || *pbReplace==0 );

  sqlite3changeset_op(pIter, &zDummy, &nCol, &op);

  if( op==SQLITE_DELETE ){


    /* Bind values to the DELETE statement. */







    rc = sessionBindValues(pIter, sqlite3changeset_old, nCol, 0, p->pDelete);
    if( rc==SQLITE_OK && sqlite3_bind_parameter_count(p->pDelete)>nCol ){
      rc = sqlite3_bind_int(p->pDelete, nCol+1, pbRetry==0);
    }
    if( rc!=SQLITE_OK ) return rc;

    sqlite3_step(p->pDelete);
    rc = sqlite3_reset(p->pDelete);
................................................................................
      ** Otherwise, if there is no primary key match, it is a NOTFOUND. */

      rc = sessionConflictHandler(
          SQLITE_CHANGESET_DATA, p, pIter, xConflict, pCtx, pbRetry
      );

    }else if( rc==SQLITE_CONSTRAINT ){
      /* This is always a CONSTRAINT conflict. */

















      rc = sessionConflictHandler(
          SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, 0
      );
    }

  }else{

    assert( op==SQLITE_INSERT );







    rc = sessionBindValues(pIter, sqlite3changeset_new, nCol, 0, p->pInsert);
    if( rc!=SQLITE_OK ) return rc;

    sqlite3_step(p->pInsert);
    rc = sqlite3_reset(p->pInsert);
    if( rc==SQLITE_CONSTRAINT ){
      rc = sessionConflictHandler(
          SQLITE_CHANGESET_CONFLICT, p, pIter, xConflict, pCtx, pbReplace
      );
    }
  }

  return rc;
................................................................................
    rc = sessionApplyOneOp(pIter, &sApply, xConflict, pCtx, &bReplace, &bRetry);

    if( rc==SQLITE_OK && bRetry ){
      rc = sessionApplyOneOp(pIter, &sApply, xConflict, pCtx, &bReplace, 0);
    }

    if( bReplace ){
      assert( pIter->op==SQLITE_INSERT );
      rc = sqlite3_exec(db, "SAVEPOINT replace_op", 0, 0, 0);
      if( rc==SQLITE_OK ){

        rc = sessionBindValues(pIter, 


            sqlite3changeset_new, sApply.nCol, sApply.abPK, sApply.pDelete);








        sqlite3_bind_int(sApply.pDelete, sApply.nCol+1, 1);
      }
      if( rc==SQLITE_OK ){
        sqlite3_step(sApply.pDelete);
        rc = sqlite3_reset(sApply.pDelete);
      }
      if( rc==SQLITE_OK ){