SQLite

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));
}

# 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} {
  1 { INSERT INTO t1 VALUES(1, 2) } 

  2 {
    INSERT INTO t2 VALUES(1, NULL);
    INSERT INTO t2 VALUES(2, NULL);
    INSERT INTO t2 VALUES(3, NULL);

    INSERT INTO t1 SELECT randomblob(32), randomblob(32) FROM t1; --  256
    INSERT INTO t1 SELECT randomblob(32), randomblob(32) FROM t1; --  512
    INSERT INTO t1 SELECT randomblob(32), randomblob(32) FROM t1; -- 1024
    INSERT INTO t1 SELECT randomblob(32), randomblob(32) FROM t1; -- 2048
    DELETE FROM t1 WHERE (rowid%3)==0;
  }

  8 {
    BEGIN;
      INSERT INTO t1 SELECT randomblob(32), randomblob(32) FROM t1;
    ROLLBACK;
  }
  9 {
    BEGIN;
      UPDATE t1 SET b = 'xxx';
    ROLLBACK;
  }
  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

  SessionChange *p,               /* Object containing old values */
  u8 *abPK,                       /* Boolean array - true for PK columns */
  int *pRc                        /* IN/OUT: Error code */
){
  if( *pRc==SQLITE_OK ){
    SessionBuffer buf2 = {0,0,0}; /* Buffer to accumulate new.* record in */
    int bNoop = 1;                /* Set to zero if any values are modified */
    int nRewind = pBuf->nBuf;     /* Set to zero if any values are modified */
    int i;                        /* Used to iterate through columns */
    u8 *pCsr = p->aRecord;        /* Used to iterate through old.* values */

    sessionAppendByte(pBuf, SQLITE_UPDATE, pRc);
    for(i=0; i<sqlite3_column_count(pStmt); i++){
      int bChanged = 0;
      int nAdvance;

        sessionAppendByte(&buf2, 0, pRc);
      }

      pCsr += nAdvance;
    }

    if( bNoop ){
      pBuf->nBuf = nRewind;
    }else{
      sessionAppendBlob(pBuf, buf2.aBuf, buf2.nBuf, pRc);

    }
    sqlite3_free(buf2.aBuf);
  }
}

static int sessionSelectStmt(
  sqlite3 *db,                    /* Database handle */
  const char *zTab,               /* Table name */
  int nCol,

  *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;
      for(i=0; i<pTab->nChange; i++){
        SessionChange *p;         /* Used to iterate through changes */

        for(p=pTab->apChange[i]; rc==SQLITE_OK && p; p=p->pNext){
          rc = sessionSelectBind(pSel, nCol, abPK, p->aRecord, p->nRecord);
          if( rc==SQLITE_OK ){
            if( sqlite3_step(pSel)==SQLITE_ROW ){
              int iCol;
              if( p->bInsert ){
                sessionAppendByte(&buf, SQLITE_INSERT, &rc);
                for(iCol=0; iCol<nCol; iCol++){
                  sessionAppendCol(&buf, pSel, iCol, &rc);
                }
              }else{
                sessionAppendUpdate(&buf, pSel, p, abPK, &rc);
              }

            }else if( !p->bInsert ){
              /* A DELETE change */
              sessionAppendByte(&buf, SQLITE_DELETE, &rc);
              sessionAppendBlob(&buf, p->aRecord, p->nRecord, &rc);

            }
            rc = sqlite3_reset(pSel);
          }
        }
      }

      sqlite3_finalize(pSel);

      if( buf.nBuf==nNoop ){
        buf.nBuf = nRewind;
      }
    }
  }

  if( rc==SQLITE_OK ){
    *pnChangeset = buf.nBuf;