Issue #993: Fixed login failure when extern_uid changes

1 files changed, 14 insertions, 0 deletions

diff --git a/db/migrate/20150817163600_deduplicate_user_identities.rb b/db/migrate/20150817163600_deduplicate_user_identities.rb
new file mode 100644
index 00000000000..fab669c2905
--- /dev/null
+++ b/db/migrate/20150817163600_deduplicate_user_identities.rb
@@ -0,0 +1,14 @@
+class DeduplicateUserIdentities < ActiveRecord::Migration
+  def change
+    execute 'DROP TABLE IF EXISTS tt_migration_DeduplicateUserIdentities;'
+    execute 'CREATE TEMPORARY TABLE tt_migration_DeduplicateUserIdentities AS SELECT id,provider,user_id FROM identities;'
+    execute 'DELETE FROM identities WHERE id NOT IN ( SELECT MIN(id) FROM tt_migration_DeduplicateUserIdentities GROUP BY user_id, provider);'
+    execute 'DROP TABLE IF EXISTS tt_migration_DeduplicateUserIdentities;'
+  end
+
+  def down
+    # This is an irreversible migration;
+    # If someone is trying to rollback for other reasons, we should not throw an Exception.
+    # raise ActiveRecord::IrreversibleMigration
+  end
+end