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Add support for chaining of WINDOW definitions.

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FossilOrigin-Name: c155125fd5dddb438c09d40f5137c47d88defb7a6ede4261f09d7bdaad250d37
This commit is contained in:
dan
2019-02-16 17:27:51 +00:00
parent 9c7e44cddd
commit e7c9ca41b2
8 changed files with 1934 additions and 1346 deletions
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95
src/window.c
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@@ -512,6 +512,17 @@ void sqlite3WindowFunctions(void){
sqlite3InsertBuiltinFuncs(aWindowFuncs, ArraySize(aWindowFuncs));
}
static Window *windowFind(Parse *pParse, Window *pList, const char *zName){
Window *p;
for(p=pList; p; p=p->pNextWin){
if( sqlite3StrICmp(p->zName, zName)==0 ) break;
}
if( p==0 ){
sqlite3ErrorMsg(pParse, "no such window: %s", zName);
}
return p;
}
/*
** This function is called immediately after resolving the function name
** for a window function within a SELECT statement. Argument pList is a
@@ -536,14 +547,8 @@ void sqlite3WindowUpdate(
FuncDef *pFunc /* Window function definition */
){
if( pWin->zName && pWin->eType==0 ){
Window *p;
for(p=pList; p; p=p->pNextWin){
if( sqlite3StrICmp(p->zName, pWin->zName)==0 ) break;
}
if( p==0 ){
sqlite3ErrorMsg(pParse, "no such window: %s", pWin->zName);
return;
}
Window *p = windowFind(pParse, pList, pWin->zName);
if( p==0 ) return;
pWin->pPartition = sqlite3ExprListDup(pParse->db, p->pPartition, 0);
pWin->pOrderBy = sqlite3ExprListDup(pParse->db, p->pOrderBy, 0);
pWin->pStart = sqlite3ExprDup(pParse->db, p->pStart, 0);
@@ -551,6 +556,8 @@ void sqlite3WindowUpdate(
pWin->eStart = p->eStart;
pWin->eEnd = p->eEnd;
pWin->eType = p->eType;
}else{
sqlite3WindowChain(pParse, pWin, pList);
}
if( pFunc->funcFlags & SQLITE_FUNC_WINDOW ){
sqlite3 *db = pParse->db;
@@ -856,6 +863,7 @@ void sqlite3WindowDelete(sqlite3 *db, Window *p){
sqlite3ExprDelete(db, p->pEnd);
sqlite3ExprDelete(db, p->pStart);
sqlite3DbFree(db, p->zName);
sqlite3DbFree(db, p->zBase);
sqlite3DbFree(db, p);
}
}
@@ -899,9 +907,10 @@ Window *sqlite3WindowAlloc(
Expr *pEnd /* End window size if TK_FOLLOWING or PRECEDING */
){
Window *pWin = 0;
int bImplicitFrame = 0;
/* Parser assures the following: */
assert( eType==TK_RANGE || eType==TK_ROWS );
assert( eType==0 || eType==TK_RANGE || eType==TK_ROWS );
assert( eStart==TK_CURRENT || eStart==TK_PRECEDING
|| eStart==TK_UNBOUNDED || eStart==TK_FOLLOWING );
assert( eEnd==TK_CURRENT || eEnd==TK_FOLLOWING
@@ -909,6 +918,10 @@ Window *sqlite3WindowAlloc(
assert( (eStart==TK_PRECEDING || eStart==TK_FOLLOWING)==(pStart!=0) );
assert( (eEnd==TK_FOLLOWING || eEnd==TK_PRECEDING)==(pEnd!=0) );
if( eType==0 ){
bImplicitFrame = 1;
eType = TK_RANGE;
}
/* If a frame is declared "RANGE" (not "ROWS"), then it may not use
** either "<expr> PRECEDING" or "<expr> FOLLOWING".
@@ -944,6 +957,7 @@ Window *sqlite3WindowAlloc(
pWin->eType = eType;
pWin->eStart = eStart;
pWin->eEnd = eEnd;
pWin->bImplicitFrame = bImplicitFrame;
pWin->pEnd = sqlite3WindowOffsetExpr(pParse, pEnd);
pWin->pStart = sqlite3WindowOffsetExpr(pParse, pStart);
return pWin;
@@ -954,6 +968,69 @@ windowAllocErr:
return 0;
}
/*
** Attach PARTITION and ORDER BY clauses pPartition and pOrderBy to window
** pWin. Also, if parameter pBase is not NULL, set pWin->zBase to the
** equivalent nul-terminated string.
*/
Window *sqlite3WindowAssemble(
Parse *pParse,
Window *pWin,
ExprList *pPartition,
ExprList *pOrderBy,
Token *pBase
){
if( pWin ){
pWin->pPartition = pPartition;
pWin->pOrderBy = pOrderBy;
if( pBase ){
pWin->zBase = sqlite3DbStrNDup(pParse->db, pBase->z, pBase->n);
}
}else{
sqlite3ExprListDelete(pParse->db, pPartition);
sqlite3ExprListDelete(pParse->db, pOrderBy);
}
return pWin;
}
/*
** Window *pWin has just been created from a WINDOW clause. Tokne pBase
** is the base window. Earlier windows from the same WINDOW clause are
** stored in the linked list starting at pWin->pNextWin. This function
** either updates *pWin according to the base specification, or else
** leaves an error in pParse.
*/
void sqlite3WindowChain(Parse *pParse, Window *pWin, Window *pList){
if( pWin->zBase ){
sqlite3 *db = pParse->db;
Window *pExist = windowFind(pParse, pList, pWin->zBase);
if( pExist ){
const char *zErr = 0;
/* Check for errors */
if( pWin->pPartition ){
zErr = "PARTITION clause";
}else if( pExist->pOrderBy && pWin->pOrderBy ){
zErr = "ORDER BY clause";
}else if( pExist->bImplicitFrame==0 ){
zErr = "frame specification";
}
if( zErr ){
sqlite3ErrorMsg(pParse,
"cannot override %s of window: %s", zErr, pWin->zBase
);
}else{
pWin->pPartition = sqlite3ExprListDup(db, pExist->pPartition, 0);
if( pExist->pOrderBy ){
assert( pWin->pOrderBy==0 );
pWin->pOrderBy = sqlite3ExprListDup(db, pExist->pOrderBy, 0);
}
sqlite3DbFree(db, pWin->zBase);
pWin->zBase = 0;
}
}
}
}
/*
** Attach window object pWin to expression p.
*/