database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-10-30 07:05:46 +03:00
Code Activity

Infrastructure changes to handle name resolution differently. This is needed

Browse Source 
to fix various long-standing problems with column names in joins.  It will
also make the implementation of correlated subqueries easier. (CVS 2228)

FossilOrigin-Name: 4a7534396a72ccb300303df28798bb2c50293782
This commit is contained in:
drh
2005-01-17 22:08:19 +00:00
parent 3719d7f9c4
commit 626a879a25
11 changed files with 503 additions and 442 deletions
Download Patch File Download Diff File Expand all files Collapse all files

43
src/sqliteInt.h
View File

@@ -11,7 +11,7 @@
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.353 2005/01/13 02:14:25 danielk1977 Exp $
** @(#) $Id: sqliteInt.h,v 1.354 2005/01/17 22:08:19 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_
@@ -316,6 +316,7 @@ typedef struct KeyClass KeyClass;
typedef struct CollSeq CollSeq;
typedef struct KeyInfo KeyInfo;
typedef struct SqlCursor SqlCursor;
typedef struct NameContext NameContext;
typedef struct Fetch Fetch;
typedef struct CursorSubst CursorSubst;
@@ -814,6 +815,8 @@ struct Expr {
** The following are the meanings of bits in the Expr.flags field.
*/
#define EP_FromJoin 0x0001 /* Originated in ON or USING clause of a join */
#define EP_Agg 0x0002 /* Contains one or more aggregate functions */
#define EP_Resolved 0x0004 /* IDs have been resolved to COLUMNs */
/*
** These macros can be used to test, set, or clear bits in the
@@ -973,6 +976,8 @@ struct Select {
ExprList *pEList; /* The fields of the result */
u8 op; /* One of: TK_UNION TK_ALL TK_INTERSECT TK_EXCEPT */
u8 isDistinct; /* True if the DISTINCT keyword is present */
u8 isAgg; /* True if uses aggregate functions */
u8 namesResolved; /* True if processed by sqlite3ExprResolve() */
SrcList *pSrc; /* The FROM clause */
Expr *pWhere; /* The WHERE clause */
ExprList *pGroupBy; /* The GROUP BY clause */
@@ -1250,6 +1255,38 @@ typedef struct {
char **pzErrMsg; /* Error message stored here */
} InitData;
/*
** A NameContext defines a context in which to resolve table and column
** names. The context consists of a list of tables (the pSrcList) field and
** a list of named expression (pEList). The named expression list may
** be NULL. The pSrc corresponds to the FROM clause of a SELECT or
** to the table being operated on by INSERT, UPDATE, or DELETE. The
** pEList corresponds to the result set of a SELECT and is NULL for
** other statements.
**
** NameContexts can be nested. When resolving names, the inner-most
** context is searched first. If no match is found, the next outer
** context is checked. If there is still no match, the next context
** is checked. This process continues until either a match is found
** or all contexts are check. When a match is found, the nRef member of
** the context containing the match is incremented.
**
** Each subquery gets a new NameContext. The pNext field points to the
** NameContext in the parent query. Thus the process of scanning the
** NameContext list corresponds to searching through successively outer
** subqueries looking for a match.
*/
struct NameContext {
Parse *pParse; /* The parser */
SrcList *pSrcList; /* One or more tables used to resolve names */
ExprList *pEList; /* Optional list of named expressions */
int nRef; /* Number of names resolved by this context */
int nErr; /* Number of errors encountered while resolving names */
u8 allowAgg; /* Aggregate functions allowed here */
u8 hasAgg; /* Expression actually contains aggregate functions */
NameContext *pNext; /* Next outer name context. NULL for outermost */
};
/*
** Each SQL cursor (a cursor created by the DECLARE ... CURSOR syntax)
** is represented by an instance of the following structure.
@@ -1386,8 +1423,8 @@ char *sqlite3NameFromToken(Token*);
int sqlite3ExprCheck(Parse*, Expr*, int, int*);
int sqlite3ExprCompare(Expr*, Expr*);
int sqliteFuncId(Token*);
int sqlite3ExprResolveIds(Parse*, SrcList*, ExprList*, Expr*);
int sqlite3ExprResolveAndCheck(Parse*,SrcList*,ExprList*,Expr*,int,int*);
int sqlite3ExprResolveNames(Parse*, SrcList*, ExprList*, Expr*, int, int*, int);
int sqlite3ExprCodeSubquery(Parse*, Expr*);
int sqlite3ExprAnalyzeAggregates(Parse*, Expr*);
Vdbe *sqlite3GetVdbe(Parse*);
void sqlite3Randomness(int, void*);