Teach pg_dump to dump comments attached to the columns of a composite type.

Taro Minowa (Higepon)

diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 900f8c2bde9825e0be6977f628d951bf45c83d7a..e05bd53d9ca7f10c8467d866bb32c7d4ee892114 100644 (file)
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -12,7 +12,7 @@
  *     by PostgreSQL
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.541 2009/07/20 20:53:40 momjian Exp $
+ *       $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.542 2009/07/23 22:59:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -134,6 +134,7 @@ static void dumpBaseType(Archive *fout, TypeInfo *tinfo);
 static void dumpEnumType(Archive *fout, TypeInfo *tinfo);
 static void dumpDomain(Archive *fout, TypeInfo *tinfo);
 static void dumpCompositeType(Archive *fout, TypeInfo *tinfo);
+static void dumpCompositeTypeColComments(Archive *fout, TypeInfo *tinfo);
 static void dumpShellType(Archive *fout, ShellTypeInfo *stinfo);
 static void dumpProcLang(Archive *fout, ProcLangInfo *plang);
 static void dumpFunc(Archive *fout, FuncInfo *finfo);
@@ -6755,6 +6756,119 @@ dumpCompositeType(Archive *fout, TypeInfo *tinfo)
        destroyPQExpBuffer(q);
        destroyPQExpBuffer(delq);
        destroyPQExpBuffer(query);
+
+       /* Dump any per-column comments */
+       dumpCompositeTypeColComments(fout, tinfo);
+}
+
+/*
+ * dumpCompositeTypeColComments
+ *       writes out to fout the queries to recreate comments on the columns of
+ *       a user-defined stand-alone composite type
+ */
+static void
+dumpCompositeTypeColComments(Archive *fout, TypeInfo *tinfo)
+{
+       CommentItem *comments;
+       int ncomments;
+       PGresult *res;
+       PQExpBuffer query;
+       PQExpBuffer target;
+       Oid pgClassOid;
+       int i;
+       int ntups;
+       int i_attname;
+       int i_attnum;
+
+       query = createPQExpBuffer();
+
+       /* We assume here that remoteVersion must be at least 70300 */
+       appendPQExpBuffer(query,
+                                         "SELECT c.tableoid, a.attname, a.attnum "
+                                         "FROM pg_catalog.pg_class c, pg_catalog.pg_attribute a "
+                                         "WHERE c.oid = '%u' AND c.oid = a.attrelid "
+                                         "  AND NOT a.attisdropped "
+                                         "ORDER BY a.attnum ",
+                                         tinfo->typrelid);
+
+       /* Fetch column attnames */
+       res = PQexec(g_conn, query->data);
+       check_sql_result(res, g_conn, query->data, PGRES_TUPLES_OK);
+
+       /* Expecting at least a single result */
+       ntups = PQntuples(res);
+       if (ntups < 1)
+       {
+               write_msg(NULL, "query returned no rows: %s\n", query->data);
+               exit_nicely();
+       }
+
+       pgClassOid = atooid(PQgetvalue(res, 0, PQfnumber(res, "tableoid")));
+
+       /* Search for comments associated with type's pg_class OID */
+       ncomments = findComments(fout,
+                                                        pgClassOid,
+                                                        tinfo->typrelid,
+                                                        &comments);
+
+       /* If no comments exist, we're done */
+       if (ncomments <= 0)
+       {
+               PQclear(res);
+               destroyPQExpBuffer(query);
+               return;
+       }
+
+       /* Build COMMENT ON statements */
+       target = createPQExpBuffer();
+
+       i_attnum = PQfnumber(res, "attnum");
+       i_attname = PQfnumber(res, "attname");
+       while (ncomments > 0)
+       {
+               const char *attname;
+
+               attname = NULL;
+               for (i = 0; i < ntups; i++)
+               {
+                       if (atoi(PQgetvalue(res, i, i_attnum)) == comments->objsubid)
+                       {
+                               attname = PQgetvalue(res, i, i_attname);
+                               break;
+                       }
+               }
+               if (attname)                    /* just in case we don't find it */
+               {
+                       const char *descr = comments->descr;
+
+                       resetPQExpBuffer(target);
+                       appendPQExpBuffer(target, "COLUMN %s.",
+                                                         fmtId(tinfo->dobj.name));
+                       appendPQExpBuffer(target, "%s",
+                                                         fmtId(attname));
+
+                       resetPQExpBuffer(query);
+                       appendPQExpBuffer(query, "COMMENT ON %s IS ", target->data);
+                       appendStringLiteralAH(query, descr, fout);
+                       appendPQExpBuffer(query, ";\n");
+
+                       ArchiveEntry(fout, nilCatalogId, createDumpId(),
+                                                target->data,
+                                                tinfo->dobj.namespace->dobj.name,
+                                                NULL, tinfo->rolname,
+                                                false, "COMMENT", SECTION_NONE,
+                                                query->data, "", NULL,
+                                                &(tinfo->dobj.dumpId), 1,
+                                                NULL, NULL);
+               }
+
+               comments++;
+               ncomments--;
+       }
+
+       PQclear(res);
+       destroyPQExpBuffer(query);
+       destroyPQExpBuffer(target);
 }
 
 /*