Display incoming as well as outgoing foreign-key constraints in psql's

\d output for a table.

Kenneth D'Souza, some changes by myself.

diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index 86b24b454946820e99f2f2101756bf27a226f01d..96c578aa70ec5647e62a82dd1b2cd02d3224416b 100644 (file)
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2008, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/describe.c,v 1.164 2008/01/01 19:45:56 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/describe.c,v 1.165 2008/03/30 17:50:11 tgl Exp $
  */
 #include "postgres_fe.h"
 #include "describe.h"
@@ -1106,12 +1106,14 @@ describeOneTableDetails(const char *schemaname,
                   *result3 = NULL,
                   *result4 = NULL,
                   *result5 = NULL,
-                  *result6 = NULL;
+                  *result6 = NULL,
+                  *result7 = NULL;
        int         check_count = 0,
                    index_count = 0,
                    foreignkey_count = 0,
                    rule_count = 0,
                    trigger_count = 0,
+                   referencedby_count = 0,
                    inherits_count = 0;
        int         count_footers = 0;
 
@@ -1228,24 +1230,47 @@ describeOneTableDetails(const char *schemaname,
                foreignkey_count = PQntuples(result5);
        }
 
+       /* count incoming foreign-key references (none if no triggers) */
+       if (tableinfo.triggers)
+       {
+           printfPQExpBuffer(&buf,
+                             "SELECT conname, conrelid::pg_catalog.regclass,\n"
+                             "  pg_catalog.pg_get_constraintdef(oid, true) as condef\n"
+                             "FROM pg_catalog.pg_constraint c\n"
+                             "WHERE c.confrelid = '%s' AND c.contype = 'f' ORDER BY 1",
+                             oid);
+           result6 = PSQLexec(buf.data, false);
+           if (!result6)
+           {
+               PQclear(result1);
+               PQclear(result2);
+               PQclear(result3);
+               PQclear(result4);
+               PQclear(result5);
+               goto error_return;
+           }
+           else
+               referencedby_count = PQntuples(result6);
+       }
+
        /* count inherited tables */
-       printfPQExpBuffer(&buf, "SELECT c.oid::regclass FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i WHERE c.oid=i.inhparent AND i.inhrelid = '%s' ORDER BY inhseqno ASC", oid);
+       printfPQExpBuffer(&buf, "SELECT c.oid::pg_catalog.regclass FROM pg_catalog.pg_class c, pg_catalog.pg_inherits i WHERE c.oid=i.inhparent AND i.inhrelid = '%s' ORDER BY inhseqno", oid);
 
-       result6 = PSQLexec(buf.data, false);
-       if (!result6)
-       {
+       result7 = PSQLexec(buf.data, false);
+       if (!result7)
+       {        
            PQclear(result1);
            PQclear(result2);
            PQclear(result3);
            PQclear(result4);
            PQclear(result5);
+           PQclear(result6);
            goto error_return;
        }
        else
-           inherits_count = PQntuples(result6);
+           inherits_count = PQntuples(result7);
 
-       footers = pg_malloc_zero((index_count + check_count + rule_count + trigger_count + foreignkey_count + inherits_count + 7 + 1)
-                                * sizeof(*footers));
+       footers = pg_malloc_zero((index_count + check_count + rule_count + trigger_count + foreignkey_count + referencedby_count + inherits_count + 8 + 1) * sizeof(*footers));
 
        /* print indexes */
        if (index_count > 0)
@@ -1333,6 +1358,22 @@ describeOneTableDetails(const char *schemaname,
            }
        }
 
+       /* print incoming foreign-key constraints */
+       if (referencedby_count > 0)
+       {
+           printfPQExpBuffer(&buf, _("Referenced by:"));
+           footers[count_footers++] = pg_strdup(buf.data);
+           for (i = 0; i < referencedby_count; i++)
+           {
+               printfPQExpBuffer(&buf, _("  \"%s\" IN %s %s"),
+                                 PQgetvalue(result6, i, 0),
+                                 PQgetvalue(result6, i, 1),
+                                 PQgetvalue(result6, i, 2));
+
+               footers[count_footers++] = pg_strdup(buf.data);
+           }
+       }
+
        /* print rules */
        if (rule_count > 0)
        {
@@ -1487,9 +1528,9 @@ describeOneTableDetails(const char *schemaname,
            const char *s = _("Inherits");
 
            if (i == 0)
-               printfPQExpBuffer(&buf, "%s: %s", s, PQgetvalue(result6, i, 0));
+               printfPQExpBuffer(&buf, "%s: %s", s, PQgetvalue(result7, i, 0));
            else
-               printfPQExpBuffer(&buf, "%*s  %s", (int) strlen(s), "", PQgetvalue(result6, i, 0));
+               printfPQExpBuffer(&buf, "%*s  %s", (int) strlen(s), "", PQgetvalue(result7, i, 0));
            if (i < inherits_count - 1)
                appendPQExpBuffer(&buf, ",");
 
@@ -1516,6 +1557,7 @@ describeOneTableDetails(const char *schemaname,
        PQclear(result4);
        PQclear(result5);
        PQclear(result6);
+       PQclear(result7);
    }
 
    printTable(title.data, headers,