Support DDL transactions

integration_test/migrations_test.exs

@@ -0,0 +1,126 @@
+defmodule Ecto.Integration.MigrationsTest do
+  use ExUnit.Case, async: true
+
+  alias Ecto.Integration.PoolRepo
+  import ExUnit.CaptureLog
+
+  @moduletag :capture_log
+  @base_migration 3_000_000
+
+  defmodule NormalMigration do
+    use Ecto.Migration
+
+    def change do
+      create_if_not_exists table(:log_mode_table)
+
+      alter table(:log_mode_table) do
+        add :name, :text
+      end
+    end
+  end
+
+  defmodule RollbackMigration do
+    use Ecto.Migration
+
+    def change do
+      create_if_not_exists table(:log_mode_table)
+
+      alter table(:log_mode_table) do
+        remove :not_exists, :text
+      end
+    end
+  end
+
+  describe "Migrator" do
+    @create_table_sql ~s(CREATE TABLE IF NOT EXISTS "log_mode_table")
+    @create_table_log "create table if not exists log_mode_table"
+    @add_column_sql ~S(ALTER TABLE "log_mode_table" ADD COLUMN "name" TEXT)
+    @alter_table_log "alter table log_mode_table"
+    @drop_column_sql ~S(ALTER TABLE "log_mode_table" DROP COLUMN "name")
+    @drop_table_sql ~s(DROP TABLE IF EXISTS "log_mode_table")
+    @drop_table_log "drop table if exists log_mode_table"
+    @version_insert ~s(INSERT INTO "schema_migrations")
+    @version_delete ~s(DELETE FROM "schema_migrations")
+
+    test "logs transaction commands" do
+      num = @base_migration + System.unique_integer([:positive])
+      up_log =
+        capture_log(fn ->
+          Ecto.Migrator.up(PoolRepo, num, NormalMigration, log_migrator_sql: :info, log_migrations_sql: :info, log: :info)
+        end)
+
+      assert up_log =~ "begin []"
+      assert up_log =~ @create_table_sql
+      assert up_log =~ @create_table_log
+      assert up_log =~ @add_column_sql
+      assert up_log =~ @alter_table_log
+      assert up_log =~ @version_insert
+      assert up_log =~ "commit []"
+
+      # two columns in the table
+      assert %{num_rows: 2} = PoolRepo.query!("PRAGMA table_info(log_mode_table)", [])
+
+      down_log =
+        capture_log(fn ->
+          Ecto.Migrator.down(PoolRepo, num, NormalMigration, log_migrator_sql: :info, log_migrations_sql: :info, log: :info)
+        end)
+
+      assert down_log =~ "begin []"
+      assert down_log =~ @drop_column_sql
+      assert down_log =~ @drop_table_sql
+      assert down_log =~ @drop_table_log
+      assert down_log =~ @version_delete
+      assert down_log =~ "commit []"
+    end
+
+    test "does not log sql when log is default" do
+      num = @base_migration + System.unique_integer([:positive])
+      up_log =
+        capture_log(fn ->
+          Ecto.Migrator.up(PoolRepo, num, NormalMigration, log: :info)
+        end)
+
+      refute up_log =~ "begin []"
+      refute up_log =~ @create_table_sql
+      assert up_log =~ @create_table_log
+      refute up_log =~ @add_column_sql
+      assert up_log =~ @alter_table_log
+      refute up_log =~ @version_insert
+      refute up_log =~ "commit []"
+
+      down_log =
+        capture_log(fn ->
+          Ecto.Migrator.down(PoolRepo, num, NormalMigration, log: :info)
+        end)
+
+      refute down_log =~ "begin []"
+      refute down_log =~ @drop_column_sql
+      refute down_log =~ @drop_table_sql
+      assert down_log =~ @drop_table_log
+      refute down_log =~ @version_delete
+      refute down_log =~ "commit []"
+    end
+
+    test "rolling back undoes previous migrations" do
+      num = @base_migration + System.unique_integer([:positive])
+      up_log =
+        capture_log(fn ->
+          try do
+            Ecto.Migrator.up(PoolRepo, num, RollbackMigration, log_migrator_sql: :info, log_migrations_sql: :info, log: :info)
+          rescue
+            _ -> :ok
+          end
+        end)
+
+      assert up_log =~ "begin []"
+      assert up_log =~ @create_table_sql
+      assert up_log =~ @create_table_log
+      assert up_log =~ "rollback []"
+      refute up_log =~ @version_insert
+      refute up_log =~ "commit []"
+
+      # table was not created due to rollback
+      assert %{num_rows: 0} = PoolRepo.query!("PRAGMA table_info(log_mode_table)", [])
+    end
+  end
+end

lib/ecto/adapters/sqlite3.ex

@@ -233,7 +233,7 @@ defmodule Ecto.Adapters.SQLite3 do
   end
 
   @impl Ecto.Adapter.Migration
-  def supports_ddl_transaction?, do: false
+  def supports_ddl_transaction?, do: true
 
   @impl Ecto.Adapter.Migration
   def lock_for_migrations(_meta, _options, fun) do