Ticket #18082: 18082.diff

django/db/backends/oracle/introspection.py

@@ -72 +72 @@
     FROM   user_constraints, USER_CONS_COLUMNS ca, USER_CONS_COLUMNS cb,
            user_tab_cols ta, user_tab_cols tb
     WHERE  user_constraints.table_name = %s AND
-           ta.table_name = %s AND
+           ta.table_name = user_constraints.table_name AND
            ta.column_name = ca.column_name AND
-           ca.table_name = %s AND
+           ca.table_name = ta.table_name AND
            user_constraints.constraint_name = ca.constraint_name AND
            user_constraints.r_constraint_name = cb.constraint_name AND
            cb.table_name = tb.table_name AND
            cb.column_name = tb.column_name AND
-           ca.position = cb.position""", [table_name, table_name, table_name])
+           ca.position = cb.position""", [table_name])
 
         relations = {}
         for row in cursor.fetchall():
@@ -93 +93 @@
             {'primary_key': boolean representing whether it's the primary key,
              'unique': boolean representing whether it's a unique index}
         """
-        # This query retrieves each index on the given table, including the
-        # first associated field name
-        # "We were in the nick of time; you were in great peril!"
+        # A column can be a part of multiple indexes. Our introspection
+        # logic ends at "if it is part of any unique index then it is unique".
+        # This can naturally be wrong - maybe it is part of a multicolumn
+        # unique index.
+        #
+        # The below SQL uses GROUP BY plus MAX to check if the index is part
+        # of any UNIQUE index.
         sql = """\
-SELECT LOWER(all_tab_cols.column_name) AS column_name,
-       CASE user_constraints.constraint_type
-           WHEN 'P' THEN 1 ELSE 0
-       END AS is_primary_key,
-       CASE user_indexes.uniqueness
-           WHEN 'UNIQUE' THEN 1 ELSE 0
-       END AS is_unique
-FROM   all_tab_cols, user_cons_columns, user_constraints, user_ind_columns, user_indexes
-WHERE  all_tab_cols.column_name = user_cons_columns.column_name (+)
-  AND  all_tab_cols.table_name = user_cons_columns.table_name (+)
-  AND  user_cons_columns.constraint_name = user_constraints.constraint_name (+)
-  AND  user_constraints.constraint_type (+) = 'P'
-  AND  user_ind_columns.column_name (+) = all_tab_cols.column_name
-  AND  user_ind_columns.table_name (+) = all_tab_cols.table_name
-  AND  user_indexes.uniqueness (+) = 'UNIQUE'
-  AND  user_indexes.index_name (+) = user_ind_columns.index_name
-  AND  all_tab_cols.table_name = UPPER(%s)
+SELECT column_name, MAX(is_primary_key) as is_primary_key,
+       MAX(is_unique) as is_unique
+  FROM (
+    SELECT LOWER(user_ind_columns.column_name) AS column_name,
+           CASE user_constraints.constraint_type
+               WHEN 'P' THEN 1 ELSE 0
+           END AS is_primary_key,
+           CASE user_indexes.uniqueness
+               WHEN 'UNIQUE' THEN 1 ELSE 0
+           END AS is_unique
+    FROM   user_constraints, user_ind_columns, user_indexes
+    WHERE  user_constraints.constraint_type (+) = 'P'
+      AND  user_constraints.index_name (+) = user_ind_columns.index_name
+      AND  user_indexes.uniqueness (+) = 'UNIQUE'
+      AND  user_indexes.index_name (+) = user_ind_columns.index_name
+      AND  user_ind_columns.table_name = UPPER(%s)
+      AND  user_ind_columns.column_position = 1
+     )
+ GROUP BY column_name
 """
         cursor.execute(sql, [table_name])
         indexes = {}
         for row in cursor.fetchall():
-            indexes[row[0]] = {'primary_key': row[1], 'unique': row[2]}
+            indexes[row[0]] = {'primary_key': bool(row[1]),
+                               'unique': bool(row[2])}
         return indexes