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Add SQL92-compliant syntax for constraints.
Implement PRIMARY KEY and UNIQUE clauses using indices.
This commit is contained in:
Thomas G. Lockhart
@ -7,13 +7,14 @@
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*
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*
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* IDENTIFICATION
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* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.51 1997/11/26 01:11:03 momjian Exp $
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* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.52 1997/12/04 23:07:18 thomas Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#include <string.h>
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#include "postgres.h"
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@ -39,7 +40,9 @@ static Query *transformRuleStmt(ParseState *query, RuleStmt *stmt);
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static Query *transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt);
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static Query *transformUpdateStmt(ParseState *pstate, ReplaceStmt *stmt);
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static Query *transformCursorStmt(ParseState *pstate, CursorStmt *stmt);
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static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt);
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List *extras = NIL;
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/*
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* parse_analyze -
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@ -65,6 +68,17 @@ parse_analyze(List *pl)
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{
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pstate = make_parsestate();
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result->qtrees[i++] = transformStmt(pstate, lfirst(pl));
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if (extras != NIL)
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{
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result->len += length(extras);
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result->qtrees = (Query **) realloc(result->qtrees, result->len * sizeof(Query *));
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while (extras != NIL)
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{
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result->qtrees[i++] = transformStmt(pstate, lfirst(extras));
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extras = lnext(extras);
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}
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}
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extras = NIL;
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pl = lnext(pl);
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if (pstate->p_target_relation != NULL)
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heap_close(pstate->p_target_relation);
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@ -90,6 +104,10 @@ transformStmt(ParseState *pstate, Node *parseTree)
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* Non-optimizable statements
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*------------------------
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*/
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case T_CreateStmt:
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result = transformCreateStmt(pstate, (CreateStmt *) parseTree);
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break;
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case T_IndexStmt:
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result = transformIndexStmt(pstate, (IndexStmt *) parseTree);
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break;
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@ -309,6 +327,316 @@ transformInsertStmt(ParseState *pstate, AppendStmt *stmt)
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return (Query *) qry;
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}
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/* makeTableName()
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* Create a table name from a list of fields.
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*/
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static char *
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makeTableName(void *elem,...);
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static char *
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makeTableName(void *elem,...)
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{
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va_list args;
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char *name;
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char buf[NAMEDATALEN+1];
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strcpy(buf,"");
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va_start(args,elem);
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name = elem;
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while (name != NULL)
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{
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/* not enough room for next part? then return nothing */
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if ((strlen(buf)+strlen(name)) >= (sizeof(buf)-1))
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return (NULL);
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if (strlen(buf) > 0) strcat(buf,"_");
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strcat(buf,name);
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name = va_arg(args,void *);
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}
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va_end(args);
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name = palloc(strlen(buf)+1);
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strcpy(name,buf);
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return (name);
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} /* makeTableName() */
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/*
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* transformCreateStmt -
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* transforms the "create table" statement
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* SQL92 allows constraints to be scattered all over, so thumb through
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* the columns and collect all constraints into one place.
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* If there are any implied indices (e.g. UNIQUE or PRIMARY KEY)
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* then expand those into multiple IndexStmt blocks.
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* - thomas 1997-12-02
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*/
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static Query *
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transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
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{
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Query *q;
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List *elements;
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Node *element;
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List *columns;
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List *dlist;
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ColumnDef *column;
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List *constraints, *clist;
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Constraint *constraint;
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List *keys;
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Ident *key;
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List *ilist;
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IndexStmt *index;
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IndexElem *iparam;
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q = makeNode(Query);
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q->commandType = CMD_UTILITY;
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elements = stmt->tableElts;
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constraints = stmt->constraints;
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columns = NIL;
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dlist = NIL;
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while (elements != NIL)
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{
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element = lfirst(elements);
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switch (nodeTag(element))
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{
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case T_ColumnDef:
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column = (ColumnDef *) element;
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#if PARSEDEBUG
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printf("transformCreateStmt- found column %s\n",column->colname);
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#endif
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columns = lappend(columns,column);
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if (column->constraints != NIL)
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{
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#if PARSEDEBUG
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printf("transformCreateStmt- found constraint(s) on column %s\n",column->colname);
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#endif
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clist = column->constraints;
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while (clist != NIL)
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{
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constraint = lfirst(clist);
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switch (constraint->contype)
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{
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case CONSTR_NOTNULL:
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#if PARSEDEBUG
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printf("transformCreateStmt- found NOT NULL constraint on column %s\n",column->colname);
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#endif
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if (column->is_not_null)
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elog(WARN,"CREATE TABLE/NOT NULL already specified"
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" for %s.%s", stmt->relname, column->colname);
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column->is_not_null = TRUE;
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break;
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case CONSTR_DEFAULT:
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#if PARSEDEBUG
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printf("transformCreateStmt- found DEFAULT clause on column %s\n",column->colname);
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#endif
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if (column->defval != NULL)
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elog(WARN,"CREATE TABLE/DEFAULT multiple values specified"
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" for %s.%s", stmt->relname, column->colname);
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column->defval = constraint->def;
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break;
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case CONSTR_PRIMARY:
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#if PARSEDEBUG
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printf("transformCreateStmt- found PRIMARY KEY clause on column %s\n",column->colname);
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#endif
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if (constraint->name == NULL)
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constraint->name = makeTableName(stmt->relname, "pkey", NULL);
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if (constraint->keys == NIL)
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constraint->keys = lappend(constraint->keys, column);
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dlist = lappend(dlist, constraint);
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break;
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case CONSTR_UNIQUE:
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#if PARSEDEBUG
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printf("transformCreateStmt- found UNIQUE clause on column %s\n",column->colname);
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#endif
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if (constraint->name == NULL)
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constraint->name = makeTableName(stmt->relname, column->colname, "key", NULL);
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if (constraint->keys == NIL)
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constraint->keys = lappend(constraint->keys, column);
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dlist = lappend(dlist, constraint);
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break;
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case CONSTR_CHECK:
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#if PARSEDEBUG
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printf("transformCreateStmt- found CHECK clause on column %s\n",column->colname);
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#endif
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constraints = lappend(constraints, constraint);
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if (constraint->name == NULL)
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constraint->name = makeTableName(stmt->relname, ".", column->colname, NULL);
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break;
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default:
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elog(WARN,"parser: internal error; unrecognized constraint",NULL);
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break;
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}
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clist = lnext(clist);
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}
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}
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break;
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case T_Constraint:
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constraint = (Constraint *) element;
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#if PARSEDEBUG
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printf("transformCreateStmt- found constraint %s\n", ((constraint->name != NULL)? constraint->name: "(unknown)"));
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#endif
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switch (constraint->contype)
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{
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case CONSTR_PRIMARY:
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#if PARSEDEBUG
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printf("transformCreateStmt- found PRIMARY KEY clause\n");
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#endif
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if (constraint->name == NULL)
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constraint->name = makeTableName(stmt->relname, "pkey", NULL);
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dlist = lappend(dlist, constraint);
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break;
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case CONSTR_UNIQUE:
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#if PARSEDEBUG
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printf("transformCreateStmt- found UNIQUE clause\n");
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#endif
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#if FALSE
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if (constraint->name == NULL)
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constraint->name = makeTableName(stmt->relname, "key", NULL);
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#endif
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dlist = lappend(dlist, constraint);
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break;
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case CONSTR_CHECK:
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#if PARSEDEBUG
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printf("transformCreateStmt- found CHECK clause\n");
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#endif
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constraints = lappend(constraints, constraint);
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break;
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case CONSTR_NOTNULL:
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case CONSTR_DEFAULT:
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elog(WARN,"parser: internal error; illegal context for constraint",NULL);
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break;
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default:
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elog(WARN,"parser: internal error; unrecognized constraint",NULL);
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break;
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}
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break;
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default:
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elog(WARN,"parser: internal error; unrecognized node",NULL);
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}
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elements = lnext(elements);
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}
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stmt->tableElts = columns;
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stmt->constraints = constraints;
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/* Now run through the "deferred list" to complete the query transformation.
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* For PRIMARY KEYs, mark each column as NOT NULL and create an index.
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* For UNIQUE, create an index as for PRIMARY KEYS, but do not insist on NOT NULL.
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*
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* Note that this code does not currently look for all possible redundant cases
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* and either ignore or stop with warning. The create will fail later when
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* names for indices turn out to be redundant, or a user might just find
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* extra useless indices which might kill performance. - thomas 1997-12-04
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*/
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ilist = NIL;
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while (dlist != NIL)
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{
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constraint = lfirst(dlist);
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if (nodeTag(constraint) != T_Constraint)
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elog(WARN,"parser: internal error; unrecognized deferred node",NULL);
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if ((constraint->contype != CONSTR_PRIMARY)
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&& (constraint->contype != CONSTR_UNIQUE))
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elog(WARN,"parser: internal error; illegal deferred constraint",NULL);
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#if PARSEDEBUG
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printf("transformCreateStmt- found deferred constraint %s\n",
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((constraint->name != NULL)? constraint->name: "(unknown)"));
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#endif
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#if PARSEDEBUG
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printf("transformCreateStmt- found deferred %s clause\n",
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(constraint->contype == CONSTR_PRIMARY? "PRIMARY KEY": "UNIQUE"));
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#endif
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index = makeNode(IndexStmt);
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ilist = lappend(ilist, index);
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index->unique = TRUE;
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if (constraint->name != NULL)
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index->idxname = constraint->name;
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else if (constraint->contype == CONSTR_PRIMARY)
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index->idxname = makeTableName(stmt->relname, "pkey", NULL);
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else
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index->idxname = NULL;
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index->relname = stmt->relname;
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index->accessMethod = "btree";
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index->indexParams = NIL;
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index->withClause = NIL;
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index->whereClause = NULL;
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keys = constraint->keys;
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while (keys != NIL)
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{
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key = lfirst(keys);
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#if PARSEDEBUG
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printf("transformCreateStmt- check key %s for column match\n", key->name);
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#endif
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columns = stmt->tableElts;
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column = NULL;
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while (columns != NIL)
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{
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column = lfirst(columns);
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#if PARSEDEBUG
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printf("transformCreateStmt- check column %s for key match\n", column->colname);
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#endif
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if (strcasecmp(column->colname,key->name) == 0) break;
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else column = NULL;
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columns = lnext(columns);
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}
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if (column == NULL)
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elog(WARN,"parser: column '%s' in key does not exist",key->name);
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if (constraint->contype == CONSTR_PRIMARY)
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{
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#if PARSEDEBUG
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printf("transformCreateStmt- mark column %s as NOT NULL\n", column->colname);
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#endif
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column->is_not_null = TRUE;
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}
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iparam = makeNode(IndexElem);
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iparam->name = strcpy(palloc(strlen(column->colname)+1), column->colname);
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iparam->args = NIL;
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iparam->class = NULL;
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iparam->tname = NULL;
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index->indexParams = lappend(index->indexParams, iparam);
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if (index->idxname == NULL)
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index->idxname = makeTableName(stmt->relname, iparam->name, "key", NULL);
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keys = lnext(keys);
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}
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if (index->idxname == NULL)
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elog(WARN,"parser: unable to construct implicit index for table %s"
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"; name too long", stmt->relname);
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dlist = lnext(dlist);
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}
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q->utilityStmt = (Node *) stmt;
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extras = ilist;
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return q;
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} /* transformCreateStmt() */
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/*
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* transformIndexStmt -
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* transforms the qualification of the index statement
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