Teach psql to display comments on languages and casts.

The output of \dL (list languages) is fairly narrow, so we just always
display the comment.  \dC (list casts) can get fairly wide, so we only
display comments if the new \dC+ option is specified.

Josh Kupershmidt

1 files changed, 39 insertions, 16 deletions

diff --git a/src/bin/psql/describe.c b/src/bin/psql/describe.c
index b50c5d647f6..e46568654e5 100644
--- a/src/bin/psql/describe.c
+++ b/src/bin/psql/describe.c
@@ -2647,8 +2647,10 @@ listLanguages(const char *pattern, bool verbose, bool showSystem)
 						  gettext_noop("Owner"));
 
 	appendPQExpBuffer(&buf,
-					  "       l.lanpltrusted AS \"%s\"",
-					  gettext_noop("Trusted"));
+					  "       l.lanpltrusted AS \"%s\",\n"
+					  "       d.description AS \"%s\"",
+					  gettext_noop("Trusted"),
+					  gettext_noop("Description"));
 
 	if (verbose)
 	{
@@ -2666,13 +2668,18 @@ listLanguages(const char *pattern, bool verbose, bool showSystem)
 	}
 
 	appendPQExpBuffer(&buf,
-					  "\nFROM pg_catalog.pg_language l\n");
+					  "\nFROM pg_catalog.pg_language l\n"
+					  "LEFT JOIN pg_catalog.pg_description d\n"
+					  "  ON d.classoid = l.tableoid AND d.objoid = l.oid\n"
+					  "  AND d.objsubid = 0\n");
 
-	processSQLNamePattern(pset.db, &buf, pattern, false, false,
-						  NULL, "l.lanname", NULL, NULL);
+	if (pattern)
+		processSQLNamePattern(pset.db, &buf, pattern, false, false,
+							  NULL, "l.lanname", NULL, NULL);
 
 	if (!showSystem && !pattern)
-		appendPQExpBuffer(&buf, "WHERE lanplcallfoid != 0\n");
+		appendPQExpBuffer(&buf, "WHERE l.lanplcallfoid != 0\n");
+
 
 	appendPQExpBuffer(&buf, "ORDER BY 1;");
 
@@ -2820,7 +2827,7 @@ listConversions(const char *pattern, bool showSystem)
  * Describes casts.
  */
 bool
-listCasts(const char *pattern)
+listCasts(const char *pattern, bool verbose)
 {
 	PQExpBufferData buf;
 	PGresult   *res;
@@ -2844,7 +2851,21 @@ listCasts(const char *pattern)
 					  "       CASE WHEN c.castcontext = 'e' THEN '%s'\n"
 					  "            WHEN c.castcontext = 'a' THEN '%s'\n"
 					  "            ELSE '%s'\n"
-					  "       END as \"%s\"\n"
+					  "       END as \"%s\"",
+					  gettext_noop("Source type"),
+					  gettext_noop("Target type"),
+					  gettext_noop("Function"),
+					  gettext_noop("no"),
+					  gettext_noop("in assignment"),
+					  gettext_noop("yes"),
+					  gettext_noop("Implicit?"));
+
+	if (verbose)
+		appendPQExpBuffer(&buf,
+						  ",\n       d.description AS \"%s\"\n",
+						  gettext_noop("Description"));
+
+	appendPQExpBuffer(&buf,
 				 "FROM pg_catalog.pg_cast c LEFT JOIN pg_catalog.pg_proc p\n"
 					  "     ON c.castfunc = p.oid\n"
 					  "     LEFT JOIN pg_catalog.pg_type ts\n"
@@ -2854,13 +2875,15 @@ listCasts(const char *pattern)
 					  "     LEFT JOIN pg_catalog.pg_type tt\n"
 					  "     ON c.casttarget = tt.oid\n"
 					  "     LEFT JOIN pg_catalog.pg_namespace nt\n"
-					  "     ON nt.oid = tt.typnamespace\n"
-					  "WHERE (true",
-					  gettext_noop("Source type"),
-					  gettext_noop("Target type"),
-					  gettext_noop("Function"),
-	  gettext_noop("no"), gettext_noop("in assignment"), gettext_noop("yes"),
-					  gettext_noop("Implicit?"));
+					  "     ON nt.oid = tt.typnamespace\n");
+
+	if (verbose)
+		appendPQExpBuffer(&buf,
+						  "     LEFT JOIN pg_catalog.pg_description d\n"
+						  "     ON d.classoid = c.tableoid AND d.objoid = "
+						  "c.oid AND d.objsubid = 0\n");
+
+	appendPQExpBuffer(&buf, "WHERE ( (true");
 
 	/*
 	 * Match name pattern against either internal or external name of either
@@ -2878,7 +2901,7 @@ listCasts(const char *pattern)
 						  "pg_catalog.format_type(tt.oid, NULL)",
 						  "pg_catalog.pg_type_is_visible(tt.oid)");
 
-	appendPQExpBuffer(&buf, ")\nORDER BY 1, 2;");
+	appendPQExpBuffer(&buf, ") )\nORDER BY 1, 2;");
 
 	res = PSQLexec(buf.data, false);
 	termPQExpBuffer(&buf);