SQLite

  OSTRACE(("FCNTL file=%p, op=%d, pArg=%p\n", pFile->h, op, pArg));
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE: {
      *(int*)pArg = pFile->locktype;
      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_LAST_ERRNO: {
      *(int*)pArg = (int)pFile->lastErrno;
      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
      return SQLITE_OK;
    }
    case SQLITE_FCNTL_CHUNK_SIZE: {
      pFile->szChunk = *(int *)pArg;
      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));

    }
    sqlite3VdbeAddOp2(v, OP_Integer, mxErr, 1);  /* reg[1] holds errors left */

    /* Do an integrity check on each database file */
    for(i=0; i<db->nDb; i++){
      HashElem *x;
      Hash *pTbls;
      int *aRoot;
      int cnt = 0;

      if( OMIT_TEMPDB && i==1 ) continue;
      if( iDb>=0 && i!=iDb ) continue;

      sqlite3CodeVerifySchema(pParse, i);
      addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1); /* Halt if out of errors */
      VdbeCoverage(v);
      sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
      sqlite3VdbeJumpHere(v, addr);

      /* Do an integrity check of the B-Tree
      **
      ** Begin by finding the root pages numbers
      ** for all tables and indices in the database.
      */
      assert( sqlite3SchemaMutexHeld(db, i, 0) );
      pTbls = &db->aDb[i].pSchema->tblHash;
      for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        if( HasRowid(pTab) ) cnt++;


        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ cnt++; }
      }
      aRoot = sqlite3DbMallocRawNN(db, sizeof(int)*(cnt+1));
      if( aRoot==0 ) break;
      for(cnt=0, x=sqliteHashFirst(pTbls); x; x=sqliteHashNext(x)){
        Table *pTab = sqliteHashData(x);
        Index *pIdx;
        if( HasRowid(pTab) ) aRoot[cnt++] = pTab->tnum;
        for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){


          aRoot[cnt++] = pIdx->tnum;
        }
      }
      aRoot[cnt] = 0;

      /* Make sure sufficient number of registers have been allocated */
      pParse->nMem = MAX( pParse->nMem, 14 );

      /* Do the b-tree integrity checks */
      sqlite3VdbeAddOp4(v, OP_IntegrityCk, 2, cnt, 1, (char*)aRoot,P4_INTARRAY);
      sqlite3VdbeChangeP5(v, (u8)i);
      addr = sqlite3VdbeAddOp1(v, OP_IsNull, 2); VdbeCoverage(v);
      sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0,
         sqlite3MPrintf(db, "*** in database %s ***\n", db->aDb[i].zName),
         P4_DYNAMIC);
      sqlite3VdbeAddOp3(v, OP_Move, 2, 4, 1);
      sqlite3VdbeAddOp3(v, OP_Concat, 4, 3, 2);

        SELECTTRACE(0x100,pParse,p,("After WHERE-clause push-down:\n"));
        sqlite3TreeViewSelect(0, p, 0);
      }
#endif
    }

    /* Generate code to implement the subquery
    **
    ** The subquery is implemented as a co-routine if all of these are true:
    **   (1)  The subquery is guaranteed to be the outer loop (so that it
    **        does not need to be computed more than once)
    **   (2)  The ALL keyword after SELECT is omitted.  (Applications are
    **        allowed to say "SELECT ALL" instead of just "SELECT" to disable
    **        the use of co-routines.)
    **   (3)  Co-routines are not disabled using sqlite3_test_control()
    **        with SQLITE_TESTCTRL_OPTIMIZATIONS.
    **
    ** TODO: Are there other reasons beside (1) to use a co-routine
    ** implementation?
    */
    if( i==0
     && (pTabList->nSrc==1
            || (pTabList->a[1].fg.jointype&(JT_LEFT|JT_CROSS))!=0)  /* (1) */
     && (p->selFlags & SF_All)==0                                   /* (2) */
     && OptimizationEnabled(db, SQLITE_SubqCoroutine)               /* (3) */
    ){
      /* Implement a co-routine that will return a single row of the result
      ** set on each invocation.
      */
      int addrTop = sqlite3VdbeCurrentAddr(v)+1;
      pItem->regReturn = ++pParse->nMem;
      sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);

  /*
  **     $db rekey KEY
  **
  ** Change the encryption key on the currently open database.
  */
  case DB_REKEY: {
#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_CODEC_FROM_TCL)
    int nKey;
    void *pKey;
#endif
    if( objc!=3 ){
      Tcl_WrongNumArgs(interp, 2, objv, "KEY");
      return TCL_ERROR;
    }
#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_CODEC_FROM_TCL)
    pKey = Tcl_GetByteArrayFromObj(objv[2], &nKey);
    rc = sqlite3_rekey(pDb->db, pKey, nKey);
    if( rc ){
      Tcl_AppendResult(interp, sqlite3_errstr(rc), (char*)0);
      rc = TCL_ERROR;
    }
#endif

  const char *zArg;
  char *zErrMsg;
  int i;
  const char *zFile;
  const char *zVfs = 0;
  int flags;
  Tcl_DString translatedFilename;
#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_CODEC_FROM_TCL)
  void *pKey = 0;
  int nKey = 0;
#endif
  int rc;

  /* In normal use, each TCL interpreter runs in a single thread.  So
  ** by default, we can turn of mutexing on SQLite database connections.

      return TCL_OK;
    }
    if( strcmp(zArg,"-sourceid")==0 ){
      Tcl_AppendResult(interp,sqlite3_sourceid(), (char*)0);
      return TCL_OK;
    }
    if( strcmp(zArg,"-has-codec")==0 ){
#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_CODEC_FROM_TCL)
      Tcl_AppendResult(interp,"1",(char*)0);
#else
      Tcl_AppendResult(interp,"0",(char*)0);
#endif
      return TCL_OK;
    }
  }
  for(i=3; i+1<objc; i+=2){
    zArg = Tcl_GetString(objv[i]);
    if( strcmp(zArg,"-key")==0 ){
#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_CODEC_FROM_TCL)
      pKey = Tcl_GetByteArrayFromObj(objv[i+1], &nKey);
#endif
    }else if( strcmp(zArg, "-vfs")==0 ){
      zVfs = Tcl_GetString(objv[i+1]);
    }else if( strcmp(zArg, "-readonly")==0 ){
      int b;
      if( Tcl_GetBooleanFromObj(interp, objv[i+1], &b) ) return TCL_ERROR;

      return TCL_ERROR;
    }
  }
  if( objc<3 || (objc&1)!=1 ){
    Tcl_WrongNumArgs(interp, 1, objv, 
      "HANDLE FILENAME ?-vfs VFSNAME? ?-readonly BOOLEAN? ?-create BOOLEAN?"
      " ?-nomutex BOOLEAN? ?-fullmutex BOOLEAN? ?-uri BOOLEAN?"
#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_CODEC_FROM_TCL)
      " ?-key CODECKEY?"
#endif
    );
    return TCL_ERROR;
  }
  zErrMsg = 0;
  p = (SqliteDb*)Tcl_Alloc( sizeof(*p) );

      zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(p->db));
      sqlite3_close(p->db);
      p->db = 0;
    }
  }else{
    zErrMsg = sqlite3_mprintf("%s", sqlite3_errstr(rc));
  }
#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_CODEC_FROM_TCL)
  if( p->db ){
    sqlite3_key(p->db, pKey, nKey);
  }
#endif
  if( p->db==0 ){
    Tcl_SetResult(interp, zErrMsg, TCL_VOLATILE);
    Tcl_Free((char*)p);

*/
static int test_key(
  void *NotUsed,
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int argc,              /* Number of arguments */
  char **argv            /* Text of each argument */
){
#if defined(SQLITE_HAS_CODEC) && !defined(SQLITE_OMIT_CODEC_FROM_TCL)
  sqlite3 *db;
  const char *zKey;
  int nKey;
  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " FILENAME\"", 0);
    return TCL_ERROR;

case OP_DropTrigger: {
  sqlite3UnlinkAndDeleteTrigger(db, pOp->p1, pOp->p4.z);
  break;
}


#ifndef SQLITE_OMIT_INTEGRITY_CHECK
/* Opcode: IntegrityCk P1 P2 P3 P4 P5
**
** Do an analysis of the currently open database.  Store in
** register P1 the text of an error message describing any problems.
** If no problems are found, store a NULL in register P1.
**
** The register P3 contains the maximum number of allowed errors.
** At most reg(P3) errors will be reported.
** In other words, the analysis stops as soon as reg(P1) errors are 
** seen.  Reg(P1) is updated with the number of errors remaining.
**
** The root page numbers of all tables in the database are integers
** stored in P4_INTARRAY argument.

**
** If P5 is not zero, the check is done on the auxiliary database
** file, not the main database file.
**
** This opcode is used to implement the integrity_check pragma.
*/
case OP_IntegrityCk: {
  int nRoot;      /* Number of tables to check.  (Number of root pages.) */
  int *aRoot;     /* Array of rootpage numbers for tables to be checked */

  int nErr;       /* Number of errors reported */
  char *z;        /* Text of the error report */
  Mem *pnErr;     /* Register keeping track of errors remaining */

  assert( p->bIsReader );
  nRoot = pOp->p2;
  aRoot = pOp->p4.ai;
  assert( nRoot>0 );

  assert( aRoot[nRoot]==0 );
  assert( pOp->p3>0 && pOp->p3<=(p->nMem-p->nCursor) );
  pnErr = &aMem[pOp->p3];
  assert( (pnErr->flags & MEM_Int)!=0 );
  assert( (pnErr->flags & (MEM_Str|MEM_Blob))==0 );
  pIn1 = &aMem[pOp->p1];




  assert( pOp->p5<db->nDb );
  assert( DbMaskTest(p->btreeMask, pOp->p5) );
  z = sqlite3BtreeIntegrityCheck(db->aDb[pOp->p5].pBt, aRoot, nRoot,
                                 (int)pnErr->u.i, &nErr);

  pnErr->u.i -= nErr;
  sqlite3VdbeMemSetNull(pIn1);
  if( nErr==0 ){
    assert( z==0 );
  }else if( z==0 ){
    goto no_mem;
  }else{

  int pc;                 /* The program counter */
  int rc;                 /* Value to return */
#ifdef SQLITE_DEBUG
  int rcApp;              /* errcode set by sqlite3_result_error_code() */
#endif
  u16 nResColumn;         /* Number of columns in one row of the result set */
  u8 errorAction;         /* Recovery action to do in case of an error */
  bft expired:1;          /* True if the VM needs to be recompiled */
  bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
  u8 minWriteFileFormat;  /* Minimum file format for writable database files */
  bft explain:2;          /* True if EXPLAIN present on SQL command */
  bft changeCntOn:1;      /* True to update the change-counter */

  bft runOnlyOnce:1;      /* Automatically expire on reset */
  bft usesStmtJournal:1;  /* True if uses a statement journal */
  bft readOnly:1;         /* True for statements that do not write */
  bft bIsReader:1;        /* True for statements that read */
  bft isPrepareV2:1;      /* True if prepared with prepare_v2() */

  int nChange;            /* Number of db changes made since last reset */
  yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
  yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
  int iStatement;         /* Statement number (or 0 if has not opened stmt) */
  u32 aCounter[5];        /* Counters used by sqlite3_stmt_status() */
#ifndef SQLITE_OMIT_TRACE
  i64 startTime;          /* Time when query started - used for profiling */

#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing UNION, INTERSECT and EXCEPT operators
# in SELECT statements.
#


set testdir [file dirname $argv0]
source $testdir/tester.tcl

# Most tests in this file depend on compound-select. But there are a couple
# right at the end that test DISTINCT, so we cannot omit the entire file.
#

   WHERE t0.a=t1.a AND t1.a=33 AND t0.b=456
  UNION
  SELECT DISTINCT t0.id, t0.a, t0.b
    FROM tx AS t0, tx AS t1
   WHERE t0.a=t1.a AND t1.a=33 AND t0.b=789
   ORDER BY 1;
} {1 33 456 2 33 789}

# Enhancement (2016-03-15):  Use a co-routine for subqueries if the
# subquery is guaranteed to be the outer-most query
#
do_execsql_test select4-16.1 {
  DROP TABLE IF EXISTS t1;
  CREATE TABLE t1(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,
  PRIMARY KEY(a,b DESC)) WITHOUT ROWID;

  WITH RECURSIVE c(x) AS (VALUES(1) UNION ALL SELECT x+1 FROM c WHERE x<100)
  INSERT INTO t1(a,b,c,d)
    SELECT x%10, x/10, x, printf('xyz%dabc',x) FROM c;

  SELECT t3.c FROM 
    (SELECT a,max(b) AS m FROM t1 WHERE a>=5 GROUP BY a) AS t2
    JOIN t1 AS t3
  WHERE t2.a=t3.a AND t2.m=t3.b
  ORDER BY t3.a;
} {95 96 97 98 99}
do_execsql_test select4-16.2 {
  SELECT t3.c FROM 
    (SELECT a,max(b) AS m FROM t1 WHERE a>=5 GROUP BY a) AS t2
    CROSS JOIN t1 AS t3
  WHERE t2.a=t3.a AND t2.m=t3.b
  ORDER BY t3.a;
} {95 96 97 98 99}
do_execsql_test select4-16.3 {
  SELECT t3.c FROM 
    (SELECT a,max(b) AS m FROM t1 WHERE a>=5 GROUP BY a) AS t2
    LEFT JOIN t1 AS t3
  WHERE t2.a=t3.a AND t2.m=t3.b
  ORDER BY t3.a;
} {95 96 97 98 99}




finish_test