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Bruce Momjian authoredBruce Momjian authored
parse_target.c 16.08 KiB
/*-------------------------------------------------------------------------
*
* parse_target.c
* handle target lists
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_target.c,v 1.4 1998/01/04 04:31:22 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "postgres.h"
#include "catalog/pg_type.h"
#include "nodes/makefuncs.h"
#include "nodes/primnodes.h"
#include "parser/parse_expr.h"
#include "parser/parse_node.h"
#include "parser/parse_relation.h"
#include "parser/parse_target.h"
#include "utils/builtins.h"
static List *expandAllTables(ParseState *pstate);
static char *figureColname(Node *expr, Node *resval);
static TargetEntry *make_targetlist_expr(ParseState *pstate,
char *colname,
Node *expr,
List *arrayRef);
/*
* transformTargetList -
* turns a list of ResTarget's into a list of TargetEntry's
*/
List *
transformTargetList(ParseState *pstate, List *targetlist)
{
List *p_target = NIL;
List *tail_p_target = NIL;
while (targetlist != NIL)
{
ResTarget *res = (ResTarget *) lfirst(targetlist);
TargetEntry *tent = makeNode(TargetEntry);
switch (nodeTag(res->val))
{
case T_Ident:
{
Node *expr;
Oid type_id;
int type_len;
char *identname;
char *resname;
identname = ((Ident *) res->val)->name;
handleTargetColname(pstate, &res->name, NULL, identname);
/*
* here we want to look for column names only, not relation
* names (even though they can be stored in Ident nodes, too)
*/
expr = transformIdent(pstate, (Node *) res->val, EXPR_COLUMN_FIRST);
type_id = exprType(expr);
type_len = typeLen(typeidType(type_id));
resname = (res->name) ? res->name : identname; tent->resdom = makeResdom((AttrNumber) pstate->p_last_resno++,
(Oid) type_id,
(Size) type_len,
resname,
(Index) 0,
(Oid) 0,
0);
tent->expr = expr;
break;
}
case T_ParamNo:
case T_FuncCall:
case T_A_Const:
case T_A_Expr:
{
Node *expr = transformExpr(pstate, (Node *) res->val, EXPR_COLUMN_FIRST);
handleTargetColname(pstate, &res->name, NULL, NULL);
/* note indirection has not been transformed */
if (pstate->p_is_insert && res->indirection != NIL)
{
/* this is an array assignment */
char *val;
char *str,
*save_str;
List *elt;
int i = 0,
ndims;
int lindx[MAXDIM],
uindx[MAXDIM];
int resdomno;
Relation rd;
Value *constval;
if (exprType(expr) != UNKNOWNOID ||
!IsA(expr, Const))
elog(WARN, "yyparse: string constant expected");
val = (char *) textout((struct varlena *)
((Const *) expr)->constvalue);
str = save_str = (char *) palloc(strlen(val) + MAXDIM * 25 + 2);
foreach(elt, res->indirection)
{
A_Indices *aind = (A_Indices *) lfirst(elt);
aind->uidx = transformExpr(pstate, aind->uidx, EXPR_COLUMN_FIRST);
if (!IsA(aind->uidx, Const))
elog(WARN,
"Array Index for Append should be a constant");
uindx[i] = ((Const *) aind->uidx)->constvalue;
if (aind->lidx != NULL)
{
aind->lidx = transformExpr(pstate, aind->lidx, EXPR_COLUMN_FIRST);
if (!IsA(aind->lidx, Const))
elog(WARN,
"Array Index for Append should be a constant");
lindx[i] = ((Const *) aind->lidx)->constvalue;
}
else
{
lindx[i] = 1;
}
if (lindx[i] > uindx[i])
elog(WARN, "yyparse: lower index cannot be greater than upper index");
sprintf(str, "[%d:%d]", lindx[i], uindx[i]);
str += strlen(str);
i++;
}
sprintf(str, "=%s", val); rd = pstate->p_target_relation;
Assert(rd != NULL);
resdomno = attnameAttNum(rd, res->name);
ndims = attnumAttNelems(rd, resdomno);
if (i != ndims)
elog(WARN, "yyparse: array dimensions do not match");
constval = makeNode(Value);
constval->type = T_String;
constval->val.str = save_str;
tent = make_targetlist_expr(pstate, res->name,
(Node *) make_const(constval),
NULL);
pfree(save_str);
}
else
{
char *colname = res->name;
/* this is not an array assignment */
if (colname == NULL)
{
/*
* if you're wondering why this is here, look
* at the yacc grammar for why a name can be
* missing. -ay
*/
colname = figureColname(expr, res->val);
}
if (res->indirection)
{
List *ilist = res->indirection;
while (ilist != NIL)
{
A_Indices *ind = lfirst(ilist);
ind->lidx = transformExpr(pstate, ind->lidx, EXPR_COLUMN_FIRST);
ind->uidx = transformExpr(pstate, ind->uidx, EXPR_COLUMN_FIRST);
ilist = lnext(ilist);
}
}
res->name = colname;
tent = make_targetlist_expr(pstate, res->name, expr,
res->indirection);
}
break;
}
case T_Attr:
{
Oid type_id;
int type_len;
Attr *att = (Attr *) res->val;
Node *result;
char *attrname;
char *resname;
Resdom *resnode;
List *attrs = att->attrs;
/*
* Target item is a single '*', expand all tables (eg.
* SELECT * FROM emp)
*/
if (att->relname != NULL && !strcmp(att->relname, "*"))
{
if (tail_p_target == NIL)
p_target = tail_p_target = expandAllTables(pstate);
else
lnext(tail_p_target) = expandAllTables(pstate);
while (lnext(tail_p_target) != NIL)
/* make sure we point to the last target entry */
tail_p_target = lnext(tail_p_target);
/*
* skip rest of while loop
*/
targetlist = lnext(targetlist);
continue;
}
/*
* Target item is relation.*, expand the table (eg.
* SELECT emp.*, dname FROM emp, dept)
*/
attrname = strVal(lfirst(att->attrs));
if (att->attrs != NIL && !strcmp(attrname, "*"))
{
/*
* tail_p_target is the target list we're building
* in the while loop. Make sure we fix it after
* appending more nodes.
*/
if (tail_p_target == NIL)
p_target = tail_p_target = expandAll(pstate, att->relname,
att->relname, &pstate->p_last_resno);
else
lnext(tail_p_target) =
expandAll(pstate, att->relname, att->relname,
&pstate->p_last_resno);
while (lnext(tail_p_target) != NIL)
/* make sure we point to the last target entry */
tail_p_target = lnext(tail_p_target);
/*
* skip the rest of the while loop
*/
targetlist = lnext(targetlist);
continue;
}
/*
* Target item is fully specified: ie.
* relation.attribute
*/
result = handleNestedDots(pstate, att, &pstate->p_last_resno,EXPR_COLUMN_FIRST);
handleTargetColname(pstate, &res->name, att->relname, attrname);
if (att->indirection != NIL)
{
List *ilist = att->indirection;
while (ilist != NIL)
{
A_Indices *ind = lfirst(ilist);
ind->lidx = transformExpr(pstate, ind->lidx, EXPR_COLUMN_FIRST);
ind->uidx = transformExpr(pstate, ind->uidx, EXPR_COLUMN_FIRST);
ilist = lnext(ilist);
}
result = (Node *) make_array_ref(result, att->indirection);
}
type_id = exprType(result);
type_len = typeLen(typeidType(type_id));
/* move to last entry */
while (lnext(attrs) != NIL)
attrs = lnext(attrs);
resname = (res->name) ? res->name : strVal(lfirst(attrs));
resnode = makeResdom((AttrNumber) pstate->p_last_resno++, (Oid) type_id,
(Size) type_len,
resname,
(Index) 0,
(Oid) 0,
0);
tent->resdom = resnode;
tent->expr = result;
break;
}
default:
/* internal error */
elog(WARN,
"internal error: do not know how to transform targetlist");
break;
}
if (p_target == NIL)
{
p_target = tail_p_target = lcons(tent, NIL);
}
else
{
lnext(tail_p_target) = lcons(tent, NIL);
tail_p_target = lnext(tail_p_target);
}
targetlist = lnext(targetlist);
}
return p_target;
}
/*
* make_targetlist_expr -
* make a TargetEntry from an expression
*
* arrayRef is a list of transformed A_Indices
*/
static TargetEntry *
make_targetlist_expr(ParseState *pstate,
char *colname,
Node *expr,
List *arrayRef)
{
Oid type_id,
attrtype;
int type_len,
attrlen;
int resdomno;
Relation rd;
bool attrisset;
TargetEntry *tent;
Resdom *resnode;
if (expr == NULL)
elog(WARN, "make_targetlist_expr: invalid use of NULL expression");
type_id = exprType(expr);
if (type_id == InvalidOid)
{
type_len = 0;
}
else
type_len = typeLen(typeidType(type_id));
/* I have no idea what the following does! */
/* It appears to process target columns that will be receiving results */
if (pstate->p_is_insert || pstate->p_is_update)
{
/*
* append or replace query -- append, replace work only on one
* relation, so multiple occurence of same resdomno is bogus
*/
rd = pstate->p_target_relation;
Assert(rd != NULL);
resdomno = attnameAttNum(rd, colname);
attrisset = attnameIsSet(rd, colname);
attrtype = attnumTypeId(rd, resdomno);
if ((arrayRef != NIL) && (lfirst(arrayRef) == NIL))
attrtype = GetArrayElementType(attrtype);
if (attrtype == BPCHAROID || attrtype == VARCHAROID)
{
attrlen = rd->rd_att->attrs[resdomno - 1]->attlen;
}
else
{
attrlen = typeLen(typeidType(attrtype));
}
#if 0
if (Input_is_string && Typecast_ok)
{
Datum val;
if (type_id == typeTypeId(type("unknown")))
{
val = (Datum) textout((struct varlena *)
((Const) lnext(expr))->constvalue);
}
else
{
val = ((Const) lnext(expr))->constvalue;
}
if (attrisset)
{
lnext(expr) = makeConst(attrtype,
attrlen,
val,
false,
true,
true, /* is set */
false);
}
else
{
lnext(expr) =
makeConst(attrtype,
attrlen,
(Datum) fmgr(typeidRetinfunc(attrtype),
val, typeidTypElem(attrtype), -1),
false,
true /* Maybe correct-- 80% chance */ ,
false, /* is not a set */
false);
}
}
else if ((Typecast_ok) && (attrtype != type_id))
{
lnext(expr) =
parser_typecast2(expr, typeidType(attrtype));
}
else if (attrtype != type_id)
{
if ((attrtype == INT2OID) && (type_id == INT4OID))
lfirst(expr) = lispInteger(INT2OID); /* handle CASHOID too */
else if ((attrtype == FLOAT4OID) && (type_id == FLOAT8OID))
lfirst(expr) = lispInteger(FLOAT4OID);
else
elog(WARN, "unequal type in tlist : %s \n", colname); }
Input_is_string = false;
Input_is_integer = false;
Typecast_ok = true;
#endif
if (attrtype != type_id)
{
if (IsA(expr, Const))
{
/* try to cast the constant */
if (arrayRef && !(((A_Indices *) lfirst(arrayRef))->lidx))
{
/* updating a single item */
Oid typelem = typeidTypElem(attrtype);
expr = (Node *) parser_typecast2(expr,
type_id,
typeidType(typelem),
attrlen);
}
else
expr = (Node *) parser_typecast2(expr,
type_id,
typeidType(attrtype),
attrlen);
}
else
{
/* currently, we can't handle casting of expressions */
elog(WARN, "parser: attribute '%s' is of type '%s' but expression is of type '%s'",
colname,
typeidTypeName(attrtype),
typeidTypeName(type_id));
}
}
if (arrayRef != NIL)
{
Expr *target_expr;
Attr *att = makeNode(Attr);
List *ar = arrayRef;
List *upperIndexpr = NIL;
List *lowerIndexpr = NIL;
att->relname = pstrdup(RelationGetRelationName(rd)->data);
att->attrs = lcons(makeString(colname), NIL);
target_expr = (Expr *) handleNestedDots(pstate, att,
&pstate->p_last_resno,
EXPR_COLUMN_FIRST);
while (ar != NIL)
{
A_Indices *ind = lfirst(ar);
if (lowerIndexpr || (!upperIndexpr && ind->lidx))
{
/*
* XXX assume all lowerIndexpr is non-null in this
* case
*/
lowerIndexpr = lappend(lowerIndexpr, ind->lidx);
}
upperIndexpr = lappend(upperIndexpr, ind->uidx);
ar = lnext(ar);
}
expr = (Node *) make_array_set(target_expr,
upperIndexpr, lowerIndexpr,
(Expr *) expr);
attrtype = attnumTypeId(rd, resdomno);
attrlen = typeLen(typeidType(attrtype));
}
}
else
{
resdomno = pstate->p_last_resno++;
attrtype = type_id;
attrlen = type_len;
}
tent = makeNode(TargetEntry);
resnode = makeResdom((AttrNumber) resdomno,
(Oid) attrtype,
(Size) attrlen,
colname,
(Index) 0,
(Oid) 0,
0);
tent->resdom = resnode;
tent->expr = expr;
return tent;
}
/*
* makeTargetNames -
* generate a list of column names if not supplied or
* test supplied column names to make sure they are in target table
* (used exclusively for inserts)
*/
List *
makeTargetNames(ParseState *pstate, List *cols)
{
List *tl = NULL;
/* Generate ResTarget if not supplied */
if (cols == NIL)
{
int numcol;
int i;
AttributeTupleForm *attr = pstate->p_target_relation->rd_att->attrs;
numcol = pstate->p_target_relation->rd_rel->relnatts;
for (i = 0; i < numcol; i++)
{
Ident *id = makeNode(Ident);
id->name = palloc(NAMEDATALEN);
StrNCpy(id->name, attr[i]->attname.data, NAMEDATALEN);
id->indirection = NIL;
id->isRel = false;
if (tl == NIL)
cols = tl = lcons(id, NIL);
else
{
lnext(tl) = lcons(id, NIL);
tl = lnext(tl);
}
}
}
else
{
foreach(tl, cols)
{
List *nxt; char *name = ((Ident *) lfirst(tl))->name;
/* elog on failure */
attnameAttNum(pstate->p_target_relation, name);
foreach(nxt, lnext(tl))
if (!strcmp(name, ((Ident *) lfirst(nxt))->name))
elog (WARN, "Attribute '%s' should be specified only once", name);
}
}
return cols;
}
/*
* expandAllTables -
* turns '*' (in the target list) into a list of attributes
* (of all relations in the range table)
*/
static List *
expandAllTables(ParseState *pstate)
{
List *target = NIL;
List *legit_rtable = NIL;
List *rt,
*rtable;
rtable = pstate->p_rtable;
if (pstate->p_is_rule)
{
/*
* skip first two entries, "*new*" and "*current*"
*/
rtable = lnext(lnext(pstate->p_rtable));
}
/* this should not happen */
if (rtable == NULL)
elog(WARN, "cannot expand: null p_rtable");
/*
* go through the range table and make a list of range table entries
* which we will expand.
*/
foreach(rt, rtable)
{
RangeTblEntry *rte = lfirst(rt);
/*
* we only expand those specify in the from clause. (This will
* also prevent us from using the wrong table in inserts: eg.
* tenk2 in "insert into tenk2 select * from tenk1;")
*/
if (!rte->inFromCl)
continue;
legit_rtable = lappend(legit_rtable, rte);
}
foreach(rt, legit_rtable)
{
RangeTblEntry *rte = lfirst(rt);
List *temp = target;
if (temp == NIL)
target = expandAll(pstate, rte->relname, rte->refname,
&pstate->p_last_resno);
else
{
while (temp != NIL && lnext(temp) != NIL)
temp = lnext(temp); lnext(temp) = expandAll(pstate, rte->relname, rte->refname,
&pstate->p_last_resno);
}
}
return target;
}
/*
* figureColname -
* if the name of the resulting column is not specified in the target
* list, we have to guess.
*
*/
static char *
figureColname(Node *expr, Node *resval)
{
switch (nodeTag(expr))
{
case T_Aggreg:
return (char *) /* XXX */
((Aggreg *) expr)->aggname;
case T_Expr:
if (((Expr *) expr)->opType == FUNC_EXPR)
{
if (nodeTag(resval) == T_FuncCall)
return ((FuncCall *) resval)->funcname;
}
break;
default:
break;
}
return "?column?";
}