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GROUP BY and HAVING installed (CVS 58)

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FossilOrigin-Name: db88a0c2d4b5c5cd05e0172f061fc33763fe3829
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drh
2000-06-06 17:27:05 +00:00
parent 4794b98035
commit 2282792a4a
9 changed files with 565 additions and 234 deletions
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39
src/sqliteInt.h
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@@ -23,7 +23,7 @@
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.17 2000/06/06 13:54:15 drh Exp $
** @(#) $Id: sqliteInt.h,v 1.18 2000/06/06 17:27:05 drh Exp $
*/
#include "sqlite.h"
#include "dbbe.h"
@@ -88,6 +88,7 @@ typedef struct Token Token;
typedef struct IdList IdList;
typedef struct WhereInfo WhereInfo;
typedef struct Select Select;
typedef struct AggExpr AggExpr;
/*
** Each database is an instance of the following structure
@@ -161,7 +162,10 @@ struct Expr {
ExprList *pList; /* A list of expressions used as a function argument */
Token token; /* An operand token */
int iTable, iField; /* When op==TK_FIELD, then this node means the
** iField-th field of the iTable-th table */
** iField-th field of the iTable-th table. When
** op==TK_FUNCTION, iField holds the function id */
int iAgg; /* When op==TK_FIELD and pParse->useAgg==TRUE, pull
** value from these element of the aggregator */
Select *pSelect; /* When the expression is a sub-select */
};
@@ -234,6 +238,30 @@ struct Select {
#define SRT_Set 3 /* Store result in a table for use with "IN" */
#define SRT_Table 4 /* Store result in a regular table */
/*
** When a SELECT uses aggregate functions (like "count(*)" or "avg(f1)")
** we have to do some additional analysis of expressions. An instance
** of the following structure holds information about a single subexpression
** somewhere in the SELECT statement. An array of these structures holds
** all the information we need to generate code for aggregate
** expressions.
**
** Note that when analyzing a SELECT containing aggregates, both
** non-aggregate field variables and aggregate functions are stored
** in the AggExpr array of the Parser structure.
**
** The pExpr field points to an expression that is part of either the
** field list, the GROUP BY clause, the HAVING clause or the ORDER BY
** clause. The expression will be freed when those clauses are cleaned
** up. Do not try to delete the expression attached to AggExpr.pExpr.
**
** If AggExpr.pExpr==0, that means the expression is "count(*)".
*/
struct AggExpr {
int isAgg; /* if TRUE contains an aggregate function */
Expr *pExpr; /* The expression */
};
/*
** An SQL parser context
*/
@@ -253,6 +281,11 @@ struct Parse {
int nTab; /* Number of previously allocated cursors */
int nMem; /* Number of memory cells used so far */
int nSet; /* Number of sets used so far */
int nAgg; /* Number of aggregate expressions */
AggExpr *aAgg; /* An array of aggregate expressions */
int iAggCount; /* Index of the count(*) aggregate in aAgg[] */
int useAgg; /* If true, extract field values from the aggregator
** while generating expressions. Normally false */
};
/*
@@ -315,3 +348,5 @@ int sqliteExprCheck(Parse*, Expr*, int, int*);
int sqliteFuncId(Token*);
int sqliteExprResolveIds(Parse*, IdList*, Expr*);
void sqliteExprResolveInSelect(Parse*, Expr*);
int sqliteExprAnalyzeAggregates(Parse*, Expr*);
void sqlitePArseInfoReset(Parse*);