Add COMMENT ON CONSTRAINT facility (from Rod Taylor's pg_constraint patch).

Fix comment.c to not depend on parser token values, per discussion awhile
back.

diff --git a/src/backend/commands/comment.c b/src/backend/commands/comment.c
index b1ce1b2ce65b84323f31e0747b20bc946dc36d32..aede51e0c98641dda059861935898c0cf5c57fea 100644 (file)
--- a/src/backend/commands/comment.c
+++ b/src/backend/commands/comment.c
@@ -7,7 +7,7 @@
  * Copyright (c) 1996-2001, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/commands/comment.c,v 1.50 2002/07/12 18:43:15 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/commands/comment.c,v 1.51 2002/07/14 23:38:13 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,6 +19,7 @@
 #include "catalog/catname.h"
 #include "catalog/indexing.h"
 #include "catalog/namespace.h"
+#include "catalog/pg_constraint.h"
 #include "catalog/pg_database.h"
 #include "catalog/pg_description.h"
 #include "catalog/pg_namespace.h"
@@ -30,7 +31,6 @@
 #include "parser/parse_func.h"
 #include "parser/parse_oper.h"
 #include "parser/parse_type.h"
-#include "parser/parse.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
 #include "utils/fmgroids.h"
@@ -57,6 +57,7 @@ static void CommentAggregate(List *aggregate, List *arguments, char *comment);
 static void CommentProc(List *function, List *arguments, char *comment);
 static void CommentOperator(List *opername, List *arguments, char *comment);
 static void CommentTrigger(List *qualname, char *comment);
+static void CommentConstraint(List *qualname, char *comment);
 
 
 /*
@@ -70,39 +71,42 @@ CommentObject(CommentStmt *stmt)
 {
    switch (stmt->objtype)
    {
-       case INDEX:
-       case SEQUENCE:
-       case TABLE:
-       case VIEW:
+       case COMMENT_ON_INDEX:
+       case COMMENT_ON_SEQUENCE:
+       case COMMENT_ON_TABLE:
+       case COMMENT_ON_VIEW:
            CommentRelation(stmt->objtype, stmt->objname, stmt->comment);
            break;
-       case COLUMN:
+       case COMMENT_ON_COLUMN:
            CommentAttribute(stmt->objname, stmt->comment);
            break;
-       case DATABASE:
+       case COMMENT_ON_DATABASE:
            CommentDatabase(stmt->objname, stmt->comment);
            break;
-       case RULE:
+       case COMMENT_ON_RULE:
            CommentRule(stmt->objname, stmt->comment);
            break;
-       case TYPE_P:
+       case COMMENT_ON_TYPE:
            CommentType(stmt->objname, stmt->comment);
            break;
-       case AGGREGATE:
+       case COMMENT_ON_AGGREGATE:
            CommentAggregate(stmt->objname, stmt->objargs, stmt->comment);
            break;
-       case FUNCTION:
+       case COMMENT_ON_FUNCTION:
            CommentProc(stmt->objname, stmt->objargs, stmt->comment);
            break;
-       case OPERATOR:
+       case COMMENT_ON_OPERATOR:
            CommentOperator(stmt->objname, stmt->objargs, stmt->comment);
            break;
-       case TRIGGER:
+       case COMMENT_ON_TRIGGER:
            CommentTrigger(stmt->objname, stmt->comment);
            break;
-       case SCHEMA:
+       case COMMENT_ON_SCHEMA:
            CommentNamespace(stmt->objname, stmt->comment);
            break;
+       case COMMENT_ON_CONSTRAINT:
+           CommentConstraint(stmt->objname, stmt->comment);
+           break;
        default:
            elog(ERROR, "An attempt was made to comment on a unknown type: %d",
                 stmt->objtype);
@@ -309,26 +313,26 @@ CommentRelation(int objtype, List *relname, char *comment)
 
    switch (objtype)
    {
-       case INDEX:
+       case COMMENT_ON_INDEX:
            if (relation->rd_rel->relkind != RELKIND_INDEX)
                elog(ERROR, "relation \"%s\" is not an index",
                     RelationGetRelationName(relation));
            break;
-       case TABLE:
+       case COMMENT_ON_SEQUENCE:
+           if (relation->rd_rel->relkind != RELKIND_SEQUENCE)
+               elog(ERROR, "relation \"%s\" is not a sequence",
+                    RelationGetRelationName(relation));
+           break;
+       case COMMENT_ON_TABLE:
            if (relation->rd_rel->relkind != RELKIND_RELATION)
                elog(ERROR, "relation \"%s\" is not a table",
                     RelationGetRelationName(relation));
            break;
-       case VIEW:
+       case COMMENT_ON_VIEW:
            if (relation->rd_rel->relkind != RELKIND_VIEW)
                elog(ERROR, "relation \"%s\" is not a view",
                     RelationGetRelationName(relation));
            break;
-       case SEQUENCE:
-           if (relation->rd_rel->relkind != RELKIND_SEQUENCE)
-               elog(ERROR, "relation \"%s\" is not a sequence",
-                    RelationGetRelationName(relation));
-           break;
    }
 
    /* Create the comment using the relation's oid */
@@ -439,7 +443,7 @@ CommentDatabase(List *qualname, char *comment)
        elog(ERROR, "you are not permitted to comment on database \"%s\"",
             database);
 
-   /* Create the comments with the pg_database oid */
+   /* Create the comment with the pg_database oid */
 
    CreateComments(oid, RelOid_pg_database, 0, comment);
 
@@ -805,7 +809,7 @@ CommentTrigger(List *qualname, char *comment)
 
    systable_endscan(scan);
 
-   /* Create the comments with the pg_trigger oid */
+   /* Create the comment with the pg_trigger oid */
 
    CreateComments(oid, RelationGetRelid(pg_trigger), 0, comment);
 
@@ -814,3 +818,83 @@ CommentTrigger(List *qualname, char *comment)
    heap_close(pg_trigger, AccessShareLock);
    heap_close(relation, NoLock);
 }
+
+
+/*
+ * CommentConstraint --
+ *
+ * Enable commenting on constraints held within the pg_constraint
+ * table.  A qualified name is required as constraint names are
+ * unique per relation.
+ */
+static void
+CommentConstraint(List *qualname, char *comment)
+{
+   int         nnames;
+   List       *relName;
+   char       *conName;
+   RangeVar   *rel;
+   Relation    pg_constraint,
+               relation;
+   HeapTuple   tuple;
+   SysScanDesc scan;
+   ScanKeyData skey[1];
+   Oid         conOid = InvalidOid;
+
+   /* Separate relname and constraint name */
+   nnames = length(qualname);
+   if (nnames < 2)
+       elog(ERROR, "CommentConstraint: must specify relation and constraint");
+   relName = ltruncate(nnames-1, listCopy(qualname));
+   conName = strVal(nth(nnames-1, qualname));
+
+   /* Open the owning relation to ensure it won't go away meanwhile */
+   rel = makeRangeVarFromNameList(relName);
+   relation = heap_openrv(rel, AccessShareLock);
+
+   /* Check object security */
+
+   if (!pg_class_ownercheck(RelationGetRelid(relation), GetUserId()))
+       aclcheck_error(ACLCHECK_NOT_OWNER, RelationGetRelationName(relation));
+
+   /*
+    * Fetch the constraint tuple from pg_constraint.  There may be more than
+    * one match, because constraints are not required to have unique names;
+    * if so, error out.
+    */
+   pg_constraint = heap_openr(ConstraintRelationName, AccessShareLock);
+
+   ScanKeyEntryInitialize(&skey[0], 0x0,
+                          Anum_pg_constraint_conrelid, F_OIDEQ,
+                          ObjectIdGetDatum(RelationGetRelid(relation)));
+
+   scan = systable_beginscan(pg_constraint, ConstraintRelidIndex, true,
+                             SnapshotNow, 1, skey);
+
+   while (HeapTupleIsValid(tuple = systable_getnext(scan)))
+   {
+       Form_pg_constraint  con = (Form_pg_constraint) GETSTRUCT(tuple);
+
+       if (strcmp(NameStr(con->conname), conName) == 0)
+       {
+           if (OidIsValid(conOid))
+               elog(ERROR, "Relation \"%s\" has multiple constraints named \"%s\"",
+                    RelationGetRelationName(relation), conName);
+           conOid = tuple->t_data->t_oid;
+       }
+   }
+
+   systable_endscan(scan);
+
+   /* If no constraint exists for the relation specified, notify user */
+   if (!OidIsValid(conOid))
+       elog(ERROR, "constraint \"%s\" for relation \"%s\" does not exist",
+            conName, RelationGetRelationName(relation));
+
+   /* Create the comment with the pg_constraint oid */
+   CreateComments(conOid, RelationGetRelid(pg_constraint), 0, comment);
+
+   /* Done, but hold lock on relation */
+   heap_close(pg_constraint, AccessShareLock);
+   heap_close(relation, NoLock);
+}

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 17128a814e534411613e99244e9d411ad4334c4a..ef83d92a6d39b0cdd366e586eeab2bce58a48f77 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.339 2002/07/12 18:43:17 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.340 2002/07/14 23:38:13 tgl Exp $
  *
  * HISTORY
  *   AUTHOR            DATE            MAJOR EVENT
@@ -2364,7 +2364,7 @@ CommentStmt:
            IS comment_text
                {
                    CommentStmt *n = makeNode(CommentStmt);
-                   n->objtype = AGGREGATE;
+                   n->objtype = COMMENT_ON_AGGREGATE;
                    n->objname = $4;
                    n->objargs = makeList1($6);
                    n->comment = $9;
@@ -2373,7 +2373,7 @@ CommentStmt:
            | COMMENT ON FUNCTION func_name func_args IS comment_text
                {
                    CommentStmt *n = makeNode(CommentStmt);
-                   n->objtype = FUNCTION;
+                   n->objtype = COMMENT_ON_FUNCTION;
                    n->objname = $4;
                    n->objargs = $5;
                    n->comment = $7;
@@ -2383,16 +2383,16 @@ CommentStmt:
            IS comment_text
                {
                    CommentStmt *n = makeNode(CommentStmt);
-                   n->objtype = OPERATOR;
+                   n->objtype = COMMENT_ON_OPERATOR;
                    n->objname = $4;
                    n->objargs = $6;
                    n->comment = $9;
                    $$ = (Node *) n;
                }
-           | COMMENT ON TRIGGER name ON any_name IS comment_text
+           | COMMENT ON CONSTRAINT name ON any_name IS comment_text
                {
                    CommentStmt *n = makeNode(CommentStmt);
-                   n->objtype = TRIGGER;
+                   n->objtype = COMMENT_ON_CONSTRAINT;
                    n->objname = lappend($6, makeString($4));
                    n->objargs = NIL;
                    n->comment = $8;
@@ -2401,7 +2401,7 @@ CommentStmt:
            | COMMENT ON RULE name ON any_name IS comment_text
                {
                    CommentStmt *n = makeNode(CommentStmt);
-                   n->objtype = RULE;
+                   n->objtype = COMMENT_ON_RULE;
                    n->objname = lappend($6, makeString($4));
                    n->objargs = NIL;
                    n->comment = $8;
@@ -2411,29 +2411,38 @@ CommentStmt:
                {
                    /* Obsolete syntax supported for awhile for compatibility */
                    CommentStmt *n = makeNode(CommentStmt);
-                   n->objtype = RULE;
+                   n->objtype = COMMENT_ON_RULE;
                    n->objname = makeList1(makeString($4));
                    n->objargs = NIL;
                    n->comment = $6;
                    $$ = (Node *) n;
                }
+           | COMMENT ON TRIGGER name ON any_name IS comment_text
+               {
+                   CommentStmt *n = makeNode(CommentStmt);
+                   n->objtype = COMMENT_ON_TRIGGER;
+                   n->objname = lappend($6, makeString($4));
+                   n->objargs = NIL;
+                   n->comment = $8;
+                   $$ = (Node *) n;
+               }
        ;
 
 comment_type:
-           COLUMN                                  { $$ = COLUMN; }
-           | DATABASE                              { $$ = DATABASE; }
-           | SCHEMA                                { $$ = SCHEMA; }
-           | INDEX                                 { $$ = INDEX; }
-           | SEQUENCE                              { $$ = SEQUENCE; }
-           | TABLE                                 { $$ = TABLE; }
-           | DOMAIN_P                              { $$ = TYPE_P; }
-           | TYPE_P                                { $$ = TYPE_P; }
-           | VIEW                                  { $$ = VIEW; }
+           COLUMN                              { $$ = COMMENT_ON_COLUMN; }
+           | DATABASE                          { $$ = COMMENT_ON_DATABASE; }
+           | SCHEMA                            { $$ = COMMENT_ON_SCHEMA; }
+           | INDEX                             { $$ = COMMENT_ON_INDEX; }
+           | SEQUENCE                          { $$ = COMMENT_ON_SEQUENCE; }
+           | TABLE                             { $$ = COMMENT_ON_TABLE; }
+           | DOMAIN_P                          { $$ = COMMENT_ON_TYPE; }
+           | TYPE_P                            { $$ = COMMENT_ON_TYPE; }
+           | VIEW                              { $$ = COMMENT_ON_VIEW; }
        ;
 
 comment_text:
-           Sconst                                  { $$ = $1; }
-           | NULL_P                                { $$ = NULL; }
+           Sconst                              { $$ = $1; }
+           | NULL_P                            { $$ = NULL; }
        ;
 
 /*****************************************************************************

diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 2fec7f66fbd9defc694620bcce3df2c212d7f5b2..f0542990f2e5d1f9cc0e2c8777ec96f54dc5d31c 100644 (file)
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.185 2002/07/12 18:43:19 tgl Exp $
+ * $Id: parsenodes.h,v 1.186 2002/07/14 23:38:13 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1165,10 +1165,25 @@ typedef struct TruncateStmt
  *             Comment On Statement
  * ----------------------
  */
+#define COMMENT_ON_AGGREGATE   100
+#define COMMENT_ON_COLUMN      101
+#define COMMENT_ON_CONSTRAINT  102
+#define COMMENT_ON_DATABASE        103
+#define COMMENT_ON_FUNCTION        104
+#define COMMENT_ON_INDEX       105
+#define COMMENT_ON_OPERATOR        106
+#define COMMENT_ON_RULE            107
+#define COMMENT_ON_SCHEMA      108
+#define COMMENT_ON_SEQUENCE        109
+#define COMMENT_ON_TABLE       110
+#define COMMENT_ON_TRIGGER     111
+#define COMMENT_ON_TYPE            112
+#define COMMENT_ON_VIEW            113
+
 typedef struct CommentStmt
 {
    NodeTag     type;
-   int         objtype;        /* Object's type */
+   int         objtype;        /* Object's type, see codes above */
    List       *objname;        /* Qualified name of the object */
    List       *objargs;        /* Arguments if needed (eg, for functions) */
    char       *comment;        /* Comment to insert, or NULL to remove */