Add tab completion for ALTER TABLE xxx ALTER CONTRAINT ... ENFORCED/INHERIT

Author: reshke

src/bin/psql/tab-complete.in.c

@@ -2893,6 +2893,16 @@ match_previous_words(int pattern_id,
 		set_completion_reference(prev3_wd);
 		COMPLETE_WITH_SCHEMA_QUERY(Query_for_constraint_of_table);
 	}
+	/* if we have ALTER TABLE <sth> ALTER|DROP|RENAME CONSTRAINT <constraint>, provide [NOT] ENFORCED or [NO] INHERIT  */
+	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER|DROP|RENAME", "CONSTRAINT", MatchAny))
+	{
+		COMPLETE_WITH("ENFORCED", "NOT ENFORCED", "NO INHERIT", "INHERIT");
+	}
+	/* if we have ALTER TABLE <sth> ALTER|DROP|RENAME CONSTRAINT <constraint> NO, provide INHERIT  */
+	else if (Matches("ALTER", "TABLE", MatchAny, "ALTER|DROP|RENAME", "CONSTRAINT", MatchAny, "NO"))
+	{
+		COMPLETE_WITH("INHERIT");
+	}
 	/* ALTER TABLE <sth> VALIDATE CONSTRAINT <non-validated constraint> */
 	else if (Matches("ALTER", "TABLE", MatchAny, "VALIDATE", "CONSTRAINT"))
 	{