Merge pull request #33280 from nkondratyev/fix/mysql-time-default-values

Fix default value for mysql time types with specified precision

activerecord/CHANGELOG.md

+*   Fix default value for mysql time types with specified precision.
+
+    *Nikolay Kondratyev*
+
 *   Fix `touch` option to behave consistently with `Persistence#touch` method.
 
     *Ryuta Kamizono*

activerecord/lib/active_record/connection_adapters/mysql/schema_statements.rb

@@ -80,8 +80,8 @@ def create_table_definition(*args)
 
           def new_column_from_field(table_name, field)
             type_metadata = fetch_type_metadata(field[:Type], field[:Extra])
-            if type_metadata.type == :datetime && /\ACURRENT_TIMESTAMP(?:\(\))?\z/i.match?(field[:Default])
-              default, default_function = nil, "CURRENT_TIMESTAMP"
+            if type_metadata.type == :datetime && /\ACURRENT_TIMESTAMP(?:\([0-6]?\))?\z/i.match?(field[:Default])
+              default, default_function = nil, field[:Default]
             else
               default, default_function = field[:Default], nil
             end

activerecord/test/cases/defaults_test.rb

@@ -106,21 +106,31 @@ class PostgresqlDefaultExpressionTest < ActiveRecord::TestCase
   class MysqlDefaultExpressionTest < ActiveRecord::TestCase
     include SchemaDumpingHelper
 
-    if ActiveRecord::Base.connection.version >= "5.6.0"
+    if subsecond_precision_supported?
       test "schema dump datetime includes default expression" do
         output = dump_table_schema("datetime_defaults")
-        assert_match %r/t\.datetime\s+"modified_datetime",\s+default: -> { "CURRENT_TIMESTAMP" }/, output
+        assert_match %r/t\.datetime\s+"modified_datetime",\s+default: -> { "CURRENT_TIMESTAMP(?:\(\))?" }/i, output
       end
-    end
 
-    test "schema dump timestamp includes default expression" do
-      output = dump_table_schema("timestamp_defaults")
-      assert_match %r/t\.timestamp\s+"modified_timestamp",\s+default: -> { "CURRENT_TIMESTAMP" }/, output
-    end
+      test "schema dump datetime includes precise default expression" do
+        output = dump_table_schema("datetime_defaults")
+        assert_match %r/t\.datetime\s+"precise_datetime",.+default: -> { "CURRENT_TIMESTAMP\(6\)" }/i, output
+      end
 
-    test "schema dump timestamp without default expression" do
-      output = dump_table_schema("timestamp_defaults")
-      assert_match %r/t\.timestamp\s+"nullable_timestamp"$/, output
+      test "schema dump timestamp includes default expression" do
+        output = dump_table_schema("timestamp_defaults")
+        assert_match %r/t\.timestamp\s+"modified_timestamp",\s+default: -> { "CURRENT_TIMESTAMP(?:\(\))?" }/i, output
+      end
+
+      test "schema dump timestamp includes precise default expression" do
+        output = dump_table_schema("timestamp_defaults")
+        assert_match %r/t\.timestamp\s+"precise_timestamp",.+default: -> { "CURRENT_TIMESTAMP\(6\)" }/i, output
+      end
+
+      test "schema dump timestamp without default expression" do
+        output = dump_table_schema("timestamp_defaults")
+        assert_match %r/t\.timestamp\s+"nullable_timestamp"$/, output
+      end
     end
   end
 

activerecord/test/schema/mysql2_specific_schema.rb

@@ -2,15 +2,17 @@
 
 ActiveRecord::Schema.define do
 
-  if ActiveRecord::Base.connection.version >= "5.6.0"
+  if subsecond_precision_supported?
     create_table :datetime_defaults, force: true do |t|
       t.datetime :modified_datetime, default: -> { "CURRENT_TIMESTAMP" }
+      t.datetime :precise_datetime, precision: 6, default: -> { "CURRENT_TIMESTAMP(6)" }
     end
-  end
 
-  create_table :timestamp_defaults, force: true do |t|
-    t.timestamp :nullable_timestamp
-    t.timestamp :modified_timestamp, default: -> { "CURRENT_TIMESTAMP" }
+    create_table :timestamp_defaults, force: true do |t|
+      t.timestamp :nullable_timestamp
+      t.timestamp :modified_timestamp, default: -> { "CURRENT_TIMESTAMP" }
+      t.timestamp :precise_timestamp, precision: 6, default: -> { "CURRENT_TIMESTAMP(6)" }
+    end
   end
 
   create_table :binary_fields, force: true do |t|