Ticket #20888: 20888-draft.diff

django/db/backends/postgresql/introspection.py

@@ -207 +207 @@
                         WHEN idx.indexprs IS NOT NULL THEN
                             pg_get_indexdef(idx.indexrelid)
                     END AS exprdef,
-                    CASE
-                        WHEN am.amcanorder THEN
-                            CASE (option & 1)
-                                WHEN 1 THEN 'DESC' ELSE 'ASC'
-                            END
+                    CASE am.amname WHEN 'btree' THEN
+                        CASE i.indoption[(i.keys).n - 1] & 1
+                            WHEN 1 THEN 'DESC' ELSE 'ASC'
+                        END
+                        ELSE NULL
                     END as ordering
                 FROM (
                     SELECT
@@ -222 +222 @@
                 LEFT JOIN pg_class c2 ON idx.indexrelid = c2.oid
                 LEFT JOIN pg_am am ON c2.relam = am.oid
                 LEFT JOIN pg_attribute attr ON attr.attrelid = c.oid AND attr.attnum = idx.key
+                LEFT JOIN (SELECT i.indexrelid, i.indrelid, i.indoption,
+                     i.indisunique, i.indisclustered, i.indpred,
+                     i.indexprs,
+                     information_schema._pg_expandarray(i.indkey) AS keys
+                   FROM pg_catalog.pg_index i) i ON (c2.oid = i.indrelid)
                 WHERE c.relname = %s
             ) s2
             GROUP BY indexname, indisunique, indisprimary, amname, exprdef;