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Completed FOREIGN KEY syntax.
Added functionality for automatic trigger creation during CREATE TABLE. Added ON DELETE RESTRICT and some others. Jan
This commit is contained in:
Jan Wieck
@ -5,7 +5,7 @@
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*
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* Copyright (c) 1994, Regents of the University of California
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*
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* $Id: analyze.c,v 1.124 1999/11/15 02:00:09 tgl Exp $
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* $Id: analyze.c,v 1.125 1999/12/06 18:02:42 wieck Exp $
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*
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*-------------------------------------------------------------------------
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*/
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@ -13,6 +13,8 @@
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#include "postgres.h"
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#include "access/heapam.h"
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#include "catalog/catname.h"
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#include "catalog/pg_index.h"
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#include "catalog/pg_type.h"
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#include "nodes/makefuncs.h"
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#include "parse.h"
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@ -35,6 +37,7 @@ static Query *transformCursorStmt(ParseState *pstate, SelectStmt *stmt);
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static Query *transformCreateStmt(ParseState *pstate, CreateStmt *stmt);
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static void transformForUpdate(Query *qry, List *forUpdate);
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static void transformFkeyGetPrimaryKey(FkConstraint *fkconstraint);
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void CheckSelectForUpdate(Query *qry);
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/* kluge to return extra info from transformCreateStmt() */
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@ -556,28 +559,32 @@ CreateIndexName(char *table_name, char *column_name, char *label, List *indices)
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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,
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*clist;
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Constraint *constraint;
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List *keys;
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Ident *key;
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List *blist = NIL; /* "before list" of things to do before
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* creating the table */
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List *ilist = NIL; /* "index list" of things to do after
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* creating the table */
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IndexStmt *index,
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*pkey = NULL;
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IndexElem *iparam;
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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,
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*clist;
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Constraint *constraint;
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List *fkconstraints, /* List of FOREIGN KEY constraints to */
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*fkclist; /* add finally */
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FkConstraint *fkconstraint;
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List *keys;
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Ident *key;
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List *blist = NIL; /* "before list" of things to do before
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* creating the table */
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List *ilist = NIL; /* "index list" of things to do after
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* creating the table */
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IndexStmt *index,
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*pkey = NULL;
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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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fkconstraints = NIL;
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constraints = stmt->constraints;
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columns = NIL;
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dlist = NIL;
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@ -648,6 +655,28 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
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foreach(clist, column->constraints)
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{
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constraint = lfirst(clist);
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/* ----------
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* If this column constraint is a FOREIGN KEY
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* constraint, then we fill in the current attributes
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* name and throw it into the list of FK constraints
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* to be processed later.
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* ----------
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*/
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if (nodeTag(constraint) == T_FkConstraint)
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{
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Ident *id = makeNode(Ident);
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id->name = column->colname;
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id->indirection = NIL;
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id->isRel = false;
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fkconstraint = (FkConstraint *)constraint;
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fkconstraint->fk_attrs = lappend(NIL, id);
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fkconstraints = lappend(fkconstraints, constraint);
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continue;
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}
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switch (constraint->contype)
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{
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case CONSTR_NULL:
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@ -735,6 +764,15 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
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}
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break;
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case T_FkConstraint:
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/* ----------
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* Table level FOREIGN KEY constraints are already complete.
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* Just remember for later.
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* ----------
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*/
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fkconstraints = lappend(fkconstraints, element);
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break;
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default:
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elog(ERROR, "parser: unrecognized node (internal error)");
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}
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@ -888,9 +926,235 @@ transformCreateStmt(ParseState *pstate, CreateStmt *stmt)
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extras_before = blist;
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extras_after = ilist;
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/*
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* Now process the FOREIGN KEY constraints and add appropriate
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* queries to the extras_after statements list.
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*
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*/
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if (fkconstraints != NIL)
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{
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CreateTrigStmt *fk_trigger;
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List *fk_attr;
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List *pk_attr;
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Ident *id;
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elog(NOTICE, "CREATE TABLE will create implicit trigger(s) for FOREIGN KEY check(s)");
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foreach (fkclist, fkconstraints)
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{
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fkconstraint = (FkConstraint *)lfirst(fkclist);
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/*
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* If the constraint has no name, set it to <unnamed>
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*
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*/
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if (fkconstraint->constr_name == NULL)
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fkconstraint->constr_name = "<unnamed>";
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/*
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* If the attribute list for the referenced table was
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* omitted, lookup for the definition of the primary key
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*
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*/
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if (fkconstraint->fk_attrs != NIL && fkconstraint->pk_attrs == NIL)
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transformFkeyGetPrimaryKey(fkconstraint);
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/*
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* Build a CREATE CONSTRAINT TRIGGER statement for the CHECK
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* action.
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*
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*/
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fk_trigger = (CreateTrigStmt *)makeNode(CreateTrigStmt);
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fk_trigger->trigname = fkconstraint->constr_name;
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fk_trigger->relname = stmt->relname;
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fk_trigger->funcname = "RI_FKey_check_ins";
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fk_trigger->before = false;
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fk_trigger->row = true;
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fk_trigger->actions[0] = 'i';
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fk_trigger->actions[1] = 'u';
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fk_trigger->actions[2] = '\0';
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fk_trigger->lang = NULL;
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fk_trigger->text = NULL;
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fk_trigger->attr = NIL;
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fk_trigger->when = NULL;
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fk_trigger->isconstraint = true;
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fk_trigger->deferrable = fkconstraint->deferrable;
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fk_trigger->initdeferred = fkconstraint->initdeferred;
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fk_trigger->constrrelname = fkconstraint->pktable_name;
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fk_trigger->args = NIL;
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fk_trigger->args = lappend(fk_trigger->args,
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fkconstraint->constr_name);
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fk_trigger->args = lappend(fk_trigger->args,
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stmt->relname);
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fk_trigger->args = lappend(fk_trigger->args,
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fkconstraint->pktable_name);
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fk_trigger->args = lappend(fk_trigger->args,
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fkconstraint->match_type);
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fk_attr = fkconstraint->fk_attrs;
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pk_attr = fkconstraint->pk_attrs;
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if (length(fk_attr) != length(pk_attr))
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{
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elog(NOTICE, "Illegal FOREIGN KEY definition REFERENCES \"%s\"",
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fkconstraint->pktable_name);
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elog(ERROR, "number of key attributes in referenced table must be equal to foreign key");
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}
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while (fk_attr != NIL)
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{
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id = (Ident *)lfirst(fk_attr);
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fk_trigger->args = lappend(fk_trigger->args, id->name);
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id = (Ident *)lfirst(pk_attr);
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fk_trigger->args = lappend(fk_trigger->args, id->name);
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fk_attr = lnext(fk_attr);
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pk_attr = lnext(pk_attr);
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}
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extras_after = lappend(extras_after, (Node *)fk_trigger);
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if ((fkconstraint->actions & FKCONSTR_ON_DELETE_MASK) != 0)
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{
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/*
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* Build a CREATE CONSTRAINT TRIGGER statement for the
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* ON DELETE action fired on the PK table !!!
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*
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*/
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fk_trigger = (CreateTrigStmt *)makeNode(CreateTrigStmt);
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fk_trigger->trigname = fkconstraint->constr_name;
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fk_trigger->relname = fkconstraint->pktable_name;
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switch ((fkconstraint->actions & FKCONSTR_ON_DELETE_MASK)
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>> FKCONSTR_ON_DELETE_SHIFT)
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{
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case FKCONSTR_ON_KEY_RESTRICT:
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fk_trigger->funcname = "RI_FKey_restrict_del";
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break;
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case FKCONSTR_ON_KEY_CASCADE:
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fk_trigger->funcname = "RI_FKey_cascade_del";
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break;
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case FKCONSTR_ON_KEY_SETNULL:
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fk_trigger->funcname = "RI_FKey_setnull_del";
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break;
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case FKCONSTR_ON_KEY_SETDEFAULT:
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fk_trigger->funcname = "RI_FKey_setdefault_del";
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break;
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default:
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elog(ERROR, "Only one ON DELETE action can be specified for FOREIGN KEY constraint");
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break;
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}
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fk_trigger->before = false;
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fk_trigger->row = true;
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fk_trigger->actions[0] = 'd';
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fk_trigger->actions[1] = '\0';
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fk_trigger->lang = NULL;
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fk_trigger->text = NULL;
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fk_trigger->attr = NIL;
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fk_trigger->when = NULL;
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fk_trigger->isconstraint = true;
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fk_trigger->deferrable = fkconstraint->deferrable;
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fk_trigger->initdeferred = fkconstraint->initdeferred;
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fk_trigger->constrrelname = stmt->relname;
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fk_trigger->args = NIL;
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fk_trigger->args = lappend(fk_trigger->args,
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fkconstraint->constr_name);
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fk_trigger->args = lappend(fk_trigger->args,
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stmt->relname);
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fk_trigger->args = lappend(fk_trigger->args,
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fkconstraint->pktable_name);
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fk_trigger->args = lappend(fk_trigger->args,
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fkconstraint->match_type);
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fk_attr = fkconstraint->fk_attrs;
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pk_attr = fkconstraint->pk_attrs;
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while (fk_attr != NIL)
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{
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id = (Ident *)lfirst(fk_attr);
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fk_trigger->args = lappend(fk_trigger->args, id->name);
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id = (Ident *)lfirst(pk_attr);
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fk_trigger->args = lappend(fk_trigger->args, id->name);
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fk_attr = lnext(fk_attr);
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pk_attr = lnext(pk_attr);
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}
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extras_after = lappend(extras_after, (Node *)fk_trigger);
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}
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if ((fkconstraint->actions & FKCONSTR_ON_UPDATE_MASK) != 0)
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{
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/*
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* Build a CREATE CONSTRAINT TRIGGER statement for the
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* ON UPDATE action fired on the PK table !!!
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*
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*/
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fk_trigger = (CreateTrigStmt *)makeNode(CreateTrigStmt);
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fk_trigger->trigname = fkconstraint->constr_name;
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fk_trigger->relname = fkconstraint->pktable_name;
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switch ((fkconstraint->actions & FKCONSTR_ON_UPDATE_MASK)
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>> FKCONSTR_ON_UPDATE_SHIFT)
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{
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case FKCONSTR_ON_KEY_RESTRICT:
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fk_trigger->funcname = "RI_FKey_restrict_upd";
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break;
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case FKCONSTR_ON_KEY_CASCADE:
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fk_trigger->funcname = "RI_FKey_cascade_upd";
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break;
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case FKCONSTR_ON_KEY_SETNULL:
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fk_trigger->funcname = "RI_FKey_setnull_upd";
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break;
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case FKCONSTR_ON_KEY_SETDEFAULT:
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fk_trigger->funcname = "RI_FKey_setdefault_upd";
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break;
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default:
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elog(ERROR, "Only one ON UPDATE action can be specified for FOREIGN KEY constraint");
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break;
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}
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fk_trigger->before = false;
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fk_trigger->row = true;
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fk_trigger->actions[0] = 'u';
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fk_trigger->actions[1] = '\0';
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fk_trigger->lang = NULL;
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fk_trigger->text = NULL;
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fk_trigger->attr = NIL;
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fk_trigger->when = NULL;
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fk_trigger->isconstraint = true;
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fk_trigger->deferrable = fkconstraint->deferrable;
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fk_trigger->initdeferred = fkconstraint->initdeferred;
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fk_trigger->constrrelname = stmt->relname;
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fk_trigger->args = NIL;
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fk_trigger->args = lappend(fk_trigger->args,
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fkconstraint->constr_name);
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fk_trigger->args = lappend(fk_trigger->args,
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stmt->relname);
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fk_trigger->args = lappend(fk_trigger->args,
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fkconstraint->pktable_name);
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fk_trigger->args = lappend(fk_trigger->args,
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fkconstraint->match_type);
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fk_attr = fkconstraint->fk_attrs;
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pk_attr = fkconstraint->pk_attrs;
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while (fk_attr != NIL)
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{
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id = (Ident *)lfirst(fk_attr);
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fk_trigger->args = lappend(fk_trigger->args, id->name);
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id = (Ident *)lfirst(pk_attr);
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fk_trigger->args = lappend(fk_trigger->args, id->name);
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fk_attr = lnext(fk_attr);
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pk_attr = lnext(pk_attr);
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}
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extras_after = lappend(extras_after, (Node *)fk_trigger);
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}
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}
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}
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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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@ -1338,3 +1602,99 @@ transformForUpdate(Query *qry, List *forUpdate)
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qry->rowMark = rowMark;
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return;
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}
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/*
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* transformFkeyGetPrimaryKey -
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*
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* Try to find the primary key attributes of a referenced table if
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* the column list in the REFERENCES specification was omitted.
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*
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*/
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static void
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transformFkeyGetPrimaryKey(FkConstraint *fkconstraint)
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{
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Relation pkrel;
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Form_pg_attribute *pkrel_attrs;
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Relation indexRd;
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HeapScanDesc indexSd;
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ScanKeyData key;
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HeapTuple indexTup;
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Form_pg_index indexStruct = NULL;
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Ident *pkattr;
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int pkattno;
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int i;
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/* ----------
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* Open the referenced table and get the attributes list
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* ----------
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*/
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pkrel = heap_openr(fkconstraint->pktable_name, AccessShareLock);
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if (pkrel == NULL)
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elog(ERROR, "referenced table \"%s\" not found",
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fkconstraint->pktable_name);
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pkrel_attrs = pkrel->rd_att->attrs;
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/* ----------
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* Open pg_index and begin a scan for all indices defined on
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* the referenced table
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* ----------
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*/
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indexRd = heap_openr(IndexRelationName, AccessShareLock);
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ScanKeyEntryInitialize(&key, 0, Anum_pg_index_indrelid,
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F_OIDEQ,
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ObjectIdGetDatum(pkrel->rd_id));
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indexSd = heap_beginscan(indexRd, /* scan desc */
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false, /* scan backward flag */
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SnapshotNow, /* NOW snapshot */
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1, /* number scan keys */
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&key); /* scan keys */
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/* ----------
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* Fetch the index with indisprimary == true
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* ----------
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*/
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while (HeapTupleIsValid(indexTup = heap_getnext(indexSd, 0)))
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{
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indexStruct = (Form_pg_index) GETSTRUCT(indexTup);
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if (indexStruct->indisprimary)
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{
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break;
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}
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}
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/* ----------
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* Check that we found it
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* ----------
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*/
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if (!HeapTupleIsValid(indexTup))
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elog(ERROR, "PRIMARY KEY for referenced table \"%s\" not found",
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fkconstraint->pktable_name);
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/* ----------
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* Now build the list of PK attributes from the indkey definition
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* using the attribute names of the PK relation descriptor
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* ----------
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*/
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for (i = 0; i < 8 && indexStruct->indkey[i] != 0; i++)
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{
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pkattno = indexStruct->indkey[i];
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pkattr = (Ident *)makeNode(Ident);
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pkattr->name = nameout(&(pkrel_attrs[pkattno - 1]->attname));
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pkattr->indirection = NIL;
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pkattr->isRel = false;
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fkconstraint->pk_attrs = lappend(fkconstraint->pk_attrs, pkattr);
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}
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/* ----------
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* End index scan and close relations
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* ----------
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*/
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heap_endscan(indexSd);
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heap_close(indexRd, AccessShareLock);
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heap_close(pkrel, AccessShareLock);
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}
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