SQLite

  sqlite3VdbeAddOp2(v, OP_Integer, 0, regZero);
  sqlite3VdbeAddOp2(v, OP_MustBeInt, reg, sqlite3VdbeCurrentAddr(v)+2);
  sqlite3VdbeAddOp3(v, OP_Ge, regZero, sqlite3VdbeCurrentAddr(v)+2, reg);
  sqlite3VdbeAddOp2(v, OP_Halt, SQLITE_ERROR, OE_Abort);
  sqlite3VdbeAppendP4(v, (void*)azErr[bEnd], P4_STATIC);
}

/*
** ROWS BETWEEN <expr> PRECEDING    AND <expr> FOLLOWING
**
**   ...
**     if( new partition ){
**       Gosub flush_partition
**     }
**     Insert (record in eph-table)
**   sqlite3WhereEnd()
**   Gosub flush_partition
**
** flush_partition:
**   OpenDup (csr -> csr2)
**   OpenDup (csr -> csr3)
**   regPrec = <expr1>            // PRECEDING expression
**   regFollow = <expr2>          // FOLLOWING expression
**   if( regPrec<0 || regFollow<0 ) throw exception!
**   Rewind (csr,csr2,csr3)       // if EOF goto flush_partition_done
**     Aggstep (csr3)
**     Next(csr3)                 // if EOF fall-through
**     if( (regFollow--)<=0 ){
**       AggFinal (xValue)
**       Gosub addrGosub
**       Next(csr)                // if EOF goto flush_partition_done
**       if( (regPrec--)<=0 ){
**         AggStep (csr2, xInverse)
**         Next(csr2)
**       }
**     }
** flush_partition_done:
**   Close (csr2)
**   Close (csr3)
**   ResetSorter (csr)
**   Return
**
** ROWS BETWEEN <expr> PRECEDING    AND CURRENT ROW
** ROWS BETWEEN CURRENT ROW         AND <expr> FOLLOWING
** ROWS BETWEEN <expr> PRECEDING    AND UNBOUNDED FOLLOWING
** ROWS BETWEEN UNBOUNDED PRECEDING AND <expr> FOLLOWING
**
**   These are similar to the above. For "CURRENT ROW", intialize the
**   register to 0. For "UNBOUNDED ..." to infinity.
**
*/
static void windowCodeRowExprStep(
  Parse *pParse, 
  Select *p,
  WhereInfo *pWInfo,
  int regGosub, 
  int addrGosub
){

  int csrFollow = pParse->nTab++;
  int regPrec;                    /* Value of <expr> PRECEDING */
  int regFollow;                  /* Value of <expr> FOLLOWING */
  int addrNext;
  int addrGoto;
  int addrIfPos1;
  int addrIfPos2;

  assert( pMWin->eStart==TK_PRECEDING 
       || pMWin->eStart==TK_CURRENT 
       || pMWin->eStart==TK_UNBOUNDED 
  );
  assert( pMWin->eEnd==TK_FOLLOWING 
       || pMWin->eEnd==TK_CURRENT 
       || pMWin->eEnd==TK_UNBOUNDED 
  );

  pParse->nMem += nSub + 2;

  /* Allocate register and label for the "flush_partition" sub-routine. */
  regFlushPart = ++pParse->nMem;
  addrFlushPart = sqlite3VdbeMakeLabel(v);
  addrDone = sqlite3VdbeMakeLabel(v);

  /* flush_partition: */
  sqlite3VdbeResolveLabel(v, addrFlushPart);
  sqlite3VdbeAddOp2(v, OP_Once, 0, sqlite3VdbeCurrentAddr(v)+3);
  sqlite3VdbeAddOp2(v, OP_OpenDup, csrPrec, pMWin->iEphCsr);
  sqlite3VdbeAddOp2(v, OP_OpenDup, csrFollow, pMWin->iEphCsr);

  /* If either regPrec or regFollow are not non-negative integers, throw 
  ** an exception.  */
  if( pMWin->pStart ){
    assert( pMWin->eStart==TK_PRECEDING );
    sqlite3ExprCode(pParse, pMWin->pStart, regPrec);
    windowCheckFrameValue(pParse, regPrec, 0);
  }
  if( pMWin->pEnd ){
    assert( pMWin->eEnd==TK_FOLLOWING );
    sqlite3ExprCode(pParse, pMWin->pEnd, regFollow);
    windowCheckFrameValue(pParse, regFollow, 1);
  }

  sqlite3VdbeAddOp2(v, OP_Null, 0, pMWin->regResult);
  sqlite3VdbeAddOp2(v, OP_Null, 0, pMWin->regAccum);






  sqlite3VdbeAddOp2(v, OP_Rewind, pMWin->iEphCsr, addrDone);
  sqlite3VdbeAddOp2(v, OP_Rewind, csrPrec, addrDone);
  sqlite3VdbeChangeP5(v, 1);
  sqlite3VdbeAddOp2(v, OP_Rewind, csrFollow, addrDone);
  sqlite3VdbeChangeP5(v, 1);

  /* Invoke AggStep function for each window function using the row that

    for(i=0; i<pWin->nArg; i++){
      sqlite3VdbeAddOp3(v, OP_Column, csrFollow, pWin->iArgCol+i, reg+i);
    }
    sqlite3VdbeAddOp3(v, OP_AggStep0, 0, reg, pWin->regAccum);
    sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);
    sqlite3VdbeChangeP5(v, (u8)pWin->nArg);
  }
  if( pMWin->eEnd==TK_UNBOUNDED ){
    sqlite3VdbeAddOp2(v, OP_Goto, 0, addrNext);
    sqlite3VdbeJumpHere(v, addrNext+1);
    addrNext = sqlite3VdbeCurrentAddr(v);
  }else{
    sqlite3VdbeJumpHere(v, addrNext+1);
  }

  if( pMWin->eEnd==TK_FOLLOWING ){
    addrIfPos1 = sqlite3VdbeAddOp3(v, OP_IfPos, regFollow, 0 , 1);
  }
  for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
    sqlite3VdbeAddOp3(v, 
        OP_AggFinal, pWin->regAccum, pWin->nArg, pWin->regResult
    );
    sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);
  }
  sqlite3VdbeAddOp2(v, OP_Gosub, regGosub, addrGosub);
  sqlite3VdbeAddOp2(v, OP_Next, pMWin->iEphCsr, sqlite3VdbeCurrentAddr(v)+2);
  sqlite3VdbeAddOp2(v, OP_Goto, 0, addrDone);

  if( pMWin->eStart==TK_CURRENT || pMWin->eStart==TK_PRECEDING ){
    if( pMWin->eStart==TK_PRECEDING ){
      addrIfPos2 = sqlite3VdbeAddOp3(v, OP_IfPos, regPrec, 0 , 1);
    }
    sqlite3VdbeAddOp2(v, OP_Next, csrPrec, sqlite3VdbeCurrentAddr(v)+1);
    for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
      int i;
      for(i=0; i<pWin->nArg; i++){
        sqlite3VdbeAddOp3(v, OP_Column, csrPrec, pWin->iArgCol+i, reg+i);
      }
      sqlite3VdbeAddOp3(v, OP_AggStep0, 1, reg, pWin->regAccum);
      sqlite3VdbeAppendP4(v, pWin->pFunc, P4_FUNCDEF);
      sqlite3VdbeChangeP5(v, (u8)pWin->nArg);
    }
    if( pMWin->eStart==TK_PRECEDING ){
      sqlite3VdbeJumpHere(v, addrIfPos2);
    }
  }
  if( pMWin->eEnd==TK_FOLLOWING ){
    sqlite3VdbeJumpHere(v, addrIfPos1);
  }
  sqlite3VdbeAddOp2(v, OP_Goto, 0, addrNext);

  /* flush_partition_done: */
  sqlite3VdbeResolveLabel(v, addrDone);
  sqlite3VdbeAddOp1(v, OP_ResetSorter, pMWin->iEphCsr);
  sqlite3VdbeAddOp1(v, OP_Return, regFlushPart);

**
** ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
** ROWS BETWEEN CURRENT ROW AND CURRENT ROW
** ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
**
**========================================================================
**










































** ROWS BETWEEN <expr> PRECEDING    AND <expr> PRECEDING
**
**   Replace the bit after "Rewind" in the above with:
**
**     if( (regFollow--)<=0 ){
**       AggStep (csr3)
**       Next (csr3)

  int regGosub, 
  int addrGosub,
  int *pbLoop
){
  Window *pMWin = p->pWin;

  if( pMWin->eType==TK_ROWS 
   && (pMWin->eStart==TK_PRECEDING || pMWin->eEnd==TK_FOLLOWING)
   && (pMWin->eStart!=TK_FOLLOWING || pMWin->eEnd==TK_PRECEDING)
  ){
    *pbLoop = 0;
    windowCodeRowExprStep(pParse, p, pWInfo, regGosub, addrGosub);
    return;
  }

  *pbLoop = 1;
  windowCodeDefaultStep(pParse, p, pWInfo, regGosub, addrGosub);
}

execsql_test 2.7 {
  SELECT a, sum(d) OVER (
    PARTITION BY b
    ORDER BY d 
    ROWS BETWEEN 0 PRECEDING AND 0 FOLLOWING
  ) FROM t1
}

execsql_test 2.8 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING
  ) FROM t1
}

execsql_test 2.9 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN UNBOUNDED PRECEDING AND 2 FOLLOWING
  ) FROM t1
}

execsql_test 2.10 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING
  ) FROM t1
}

execsql_test 2.11 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN 2 PRECEDING AND CURRENT ROW
  ) FROM t1
}

execsql_test 2.13 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN 2 PRECEDING AND UNBOUNDED FOLLOWING
  ) FROM t1
}


==========

puts $::fd finish_test
==========

execsql_test 3.1 {
  SELECT a, sum(d) OVER (
    PARTITION BY b ORDER BY d

  SELECT a, sum(d) OVER (
    PARTITION BY b
    ORDER BY d 
    ROWS BETWEEN 0 PRECEDING AND 0 FOLLOWING
  ) FROM t1
} {2 2   4 4   6 6   1 1   3 3   5 5}

do_execsql_test 2.8 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING
  ) FROM t1
} {1 6   2 9   3 12   4 15   5 11   6 6}

do_execsql_test 2.9 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN UNBOUNDED PRECEDING AND 2 FOLLOWING
  ) FROM t1
} {1 6   2 10   3 15   4 21   5 21   6 21}

do_execsql_test 2.10 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN CURRENT ROW AND 2 FOLLOWING
  ) FROM t1
} {1 6   2 9   3 12   4 15   5 11   6 6}

do_execsql_test 2.11 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN 2 PRECEDING AND CURRENT ROW
  ) FROM t1
} {1 1   2 3   3 6   4 9   5 12   6 15}

do_execsql_test 2.13 {
  SELECT a, sum(d) OVER (
    ORDER BY d 
    ROWS BETWEEN 2 PRECEDING AND UNBOUNDED FOLLOWING
  ) FROM t1
} {1 21   2 21   3 21   4 20   5 18   6 15}

#==========================================================================

finish_test
#==========================================================================

do_execsql_test 3.1 {
  SELECT a, sum(d) OVER (
    PARTITION BY b ORDER BY d
    RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
  ) FROM t1
} {2 12   4 10   6 6   1 9   3 8   5 5}

do_execsql_test 3.2 {
  SELECT a, sum(d) OVER (
    ORDER BY b
    RANGE BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
  ) FROM t1
} {2 21   4 21   6 21   1 9   3 9   5 9}

do_execsql_test 3.3 {
  SELECT a, sum(d) OVER (
    ORDER BY d
    ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
  ) FROM t1
} {1 21   2 21   3 21   4 21   5 21   6 21}















finish_test