proc do_common_sql {sql} {
  execsql $sql db
  execsql $sql db2
}
proc xConflict args { return "OMIT" }

proc do_then_apply_sql {sql} {

  sqlite3session S db main
  db eval {SELECT name FROM sqlite_master WHERE type = 'table'} {
    S attach $name
  }

  db eval $sql
  sqlite3changeset_apply db2 [S changeset] xConflict
  S delete
}
................................................................................
  }
  10 {
    BEGIN;
      DELETE FROM t1 WHERE 1;
    ROLLBACK;
  }
} {
if {$tn==9} breakpoint
  do_then_apply_sql $sql
  do_test $tn { compare_db db db2 } {}
}
























































































finish_test

proc do_common_sql {sql} {
  execsql $sql db
  execsql $sql db2
}
proc xConflict args { return "OMIT" }

proc do_then_apply_sql {sql {dbname main}} {

  sqlite3session S db $dbname
  db eval "SELECT name FROM $dbname.sqlite_master WHERE type = 'table'" {
    S attach $name
  }

  db eval $sql
  sqlite3changeset_apply db2 [S changeset] xConflict
  S delete
}
................................................................................
  }
  10 {
    BEGIN;
      DELETE FROM t1 WHERE 1;
    ROLLBACK;
  }
} {

  do_then_apply_sql $sql
  do_test 1.$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
# modified within the attached db.
#
test_reset
forcedelete test.db3
sqlite3 db3 test.db3
do_test 2.0 {
  execsql {
    ATTACH 'test.db3' AS 'aux';
    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
} {}

foreach {tn sql} {
  1 { INSERT INTO aux.t1 VALUES(1, 2) } 

  2 {
    INSERT INTO aux.t2 VALUES(1, NULL);
    INSERT INTO aux.t2 VALUES(2, NULL);
    INSERT INTO aux.t2 VALUES(3, NULL);
    DELETE FROM aux.t2 WHERE a = 2;
    INSERT INTO aux.t2 VALUES(4, NULL);
    UPDATE aux.t2 SET b=0 WHERE b=1;
  } 

  3 { INSERT INTO aux.t3 SELECT *, NULL FROM aux.t2 }

  4 {
    INSERT INTO aux.t3 SELECT a||a, b||b, NULL FROM aux.t3;
    DELETE FROM aux.t3 WHERE rowid%2;
  }

  5 { UPDATE aux.t3 SET c = a||b }

  6 { UPDATE aux.t1 SET a = 32 }

  7 { 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1; 
    DELETE FROM aux.t1 WHERE (rowid%3)==0;
  }

  8 {
    BEGIN;
      INSERT INTO aux.t1 SELECT randomblob(32), randomblob(32) FROM aux.t1;
    ROLLBACK;
  }
  9 {
    BEGIN;
      UPDATE aux.t1 SET b = 'xxx';
    ROLLBACK;
  }
  10 {
    BEGIN;
      DELETE FROM aux.t1 WHERE 1;
    ROLLBACK;
  }
} {
  do_then_apply_sql $sql aux
  do_test 2.$tn { compare_db db3 db2 } {}
}


catch {db3 close}

finish_test

    }
    sqlite3_free(buf2.aBuf);
  }
}

static int sessionSelectStmt(
  sqlite3 *db,                    /* Database handle */

  const char *zTab,               /* Table name */
  int nCol,
  const char **azCol,
  u8 *abPK,
  sqlite3_stmt **ppStmt
){
  int rc = SQLITE_OK;
  int i;
  const char *zSep = "";
  SessionBuffer buf = {0, 0, 0};

  sessionAppendStr(&buf, "SELECT * FROM ", &rc);


  sessionAppendIdent(&buf, zTab, &rc);
  sessionAppendStr(&buf, " WHERE ", &rc);
  for(i=0; i<nCol; i++){
    if( abPK[i] ){
      sessionAppendStr(&buf, zSep, &rc);
      sessionAppendIdent(&buf, azCol[i], &rc);
      sessionAppendStr(&buf, " = ?", &rc);
................................................................................
  ** this call will be a no-op.  */
  *pnChangeset = 0;
  *ppChangeset = 0;
  rc = pSession->rc;

  for(pTab=pSession->pTable; rc==SQLITE_OK && pTab; pTab=pTab->pNext){
    if( pTab->nEntry ){

      int nCol = pTab->nCol;      /* Local copy of member variable */
      u8 *abPK = pTab->abPK;      /* Local copy of member variable */
      int i;                      /* Used to iterate through hash buckets */
      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, (u8 *)pTab->zName, strlen(pTab->zName)+1, &rc);

      /* Build and compile a statement to execute: */
      if( rc==SQLITE_OK ){

        rc = sessionSelectStmt(db, pTab->zName, nCol, pTab->azCol, abPK, &pSel);
      }

      if( rc==SQLITE_OK && nCol!=sqlite3_column_count(pSel) ){
        rc = SQLITE_SCHEMA;
      }

      nNoop = buf.nBuf;
................................................................................
** pointing to the prepared version of the SQL statement.
*/
static int sessionSelectRow(
  sqlite3 *db,                    /* Database handle */
  const char *zTab,               /* Table name */
  SessionApplyCtx *p              /* Session changeset-apply context */
){

  return sessionSelectStmt(db, zTab, p->nCol, p->azCol, p->abPK, &p->pSelect);
}

/*
** Formulate and prepare an INSERT statement to add a record to table zTab.
** For example:
**
**     INSERT INTO main."zTab" VALUES(?1, ?2, ?3 ...);

    }
    sqlite3_free(buf2.aBuf);
  }
}

static int sessionSelectStmt(
  sqlite3 *db,                    /* Database handle */
  const char *zDb,                /* Database name */
  const char *zTab,               /* Table name */
  int nCol,
  const char **azCol,
  u8 *abPK,
  sqlite3_stmt **ppStmt
){
  int rc = SQLITE_OK;
  int i;
  const char *zSep = "";
  SessionBuffer buf = {0, 0, 0};

  sessionAppendStr(&buf, "SELECT * FROM ", &rc);
  sessionAppendIdent(&buf, zDb, &rc);
  sessionAppendStr(&buf, ".", &rc);
  sessionAppendIdent(&buf, zTab, &rc);
  sessionAppendStr(&buf, " WHERE ", &rc);
  for(i=0; i<nCol; i++){
    if( abPK[i] ){
      sessionAppendStr(&buf, zSep, &rc);
      sessionAppendIdent(&buf, azCol[i], &rc);
      sessionAppendStr(&buf, " = ?", &rc);
................................................................................
  ** this call will be a no-op.  */
  *pnChangeset = 0;
  *ppChangeset = 0;
  rc = pSession->rc;

  for(pTab=pSession->pTable; rc==SQLITE_OK && pTab; pTab=pTab->pNext){
    if( pTab->nEntry ){
      const char *zName = pTab->zName;
      int nCol = pTab->nCol;      /* Local copy of member variable */
      u8 *abPK = pTab->abPK;      /* Local copy of member variable */
      int i;                      /* Used to iterate through hash buckets */
      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, (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);
      }

      if( rc==SQLITE_OK && nCol!=sqlite3_column_count(pSel) ){
        rc = SQLITE_SCHEMA;
      }

      nNoop = buf.nBuf;
................................................................................
** pointing to the prepared version of the SQL statement.
*/
static int sessionSelectRow(
  sqlite3 *db,                    /* Database handle */
  const char *zTab,               /* Table name */
  SessionApplyCtx *p              /* Session changeset-apply context */
){
  return sessionSelectStmt(
      db, "main", zTab, p->nCol, p->azCol, p->abPK, &p->pSelect);
}

/*
** Formulate and prepare an INSERT statement to add a record to table zTab.
** For example:
**
**     INSERT INTO main."zTab" VALUES(?1, ?2, ?3 ...);