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Fix handling of window frames containing negative number of rows. e.g. "ROWS x

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PRECEDING AND y PRECEDING" where (x<y).

FossilOrigin-Name: b6d9c7eda853420ae46a05bd432711e8bf9ebaa448c7d90ccfc0bcc338a87706
This commit is contained in:
dan
2018-06-11 18:16:51 +00:00
parent 72a9f0233b
commit 26522d1c45
7 changed files with 146 additions and 21 deletions
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27
src/window.c
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@@ -1,4 +1,5 @@
/*
** 2018 May 08
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
@@ -1258,13 +1259,26 @@ static void windowCodeRowExprStep(
/* If this is "ROWS <expr1> FOLLOWING AND ROWS <expr2> FOLLOWING", do:
**
** if( regEnd<regStart ){
** // The frame always consists of 0 rows
** regStart = regSize;
** }
** regEnd = regEnd - regStart;
*/
if( pMWin->pEnd && pMWin->pStart && pMWin->eStart==TK_FOLLOWING ){
assert( pMWin->eEnd==TK_FOLLOWING );
sqlite3VdbeAddOp3(v, OP_Ge, regStart, sqlite3VdbeCurrentAddr(v)+2, regEnd);
sqlite3VdbeAddOp2(v, OP_Copy, regSize, regStart);
sqlite3VdbeAddOp3(v, OP_Subtract, regStart, regEnd, regEnd);
}
if( pMWin->pEnd && pMWin->pStart && pMWin->eEnd==TK_PRECEDING ){
assert( pMWin->eStart==TK_PRECEDING );
sqlite3VdbeAddOp3(v, OP_Le, regStart, sqlite3VdbeCurrentAddr(v)+3, regEnd);
sqlite3VdbeAddOp2(v, OP_Copy, regSize, regStart);
sqlite3VdbeAddOp2(v, OP_Copy, regSize, regEnd);
}
/* Initialize the accumulator register for each window function to NULL */
regArg = windowInitAccum(pParse, pMWin);
@@ -1731,6 +1745,14 @@ void sqlite3WindowCodeStep(
Window *pMWin = p->pWin;
Window *pWin;
/*
** Call windowCodeRowExprStep() for all window modes *except*:
**
** RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
** RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING
** RANGE BETWEEN CURRENT ROW AND CURRENT ROW
** ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW
*/
if( (pMWin->eType==TK_ROWS
&& (pMWin->eStart!=TK_UNBOUNDED||pMWin->eEnd!=TK_CURRENT||!pMWin->pOrderBy))
|| (pMWin->eStart==TK_CURRENT&&pMWin->eEnd==TK_UNBOUNDED&&pMWin->pOrderBy)
@@ -1739,6 +1761,11 @@ void sqlite3WindowCodeStep(
return;
}
/*
** Call windowCodeCacheStep() if there is a window function that requires
** that the entire partition be cached in a temp table before any rows
** are returned.
*/
for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
FuncDef *pFunc = pWin->pFunc;
if( (pFunc->funcFlags & SQLITE_FUNC_WINDOW_SIZE)