diff --git a/activerecord/test/cases/adapters/mysql/datetime_test.rb b/activerecord/test/cases/adapters/mysql/datetime_test.rb
deleted file mode 100644
index ae00f4e131..0000000000
--- a/activerecord/test/cases/adapters/mysql/datetime_test.rb
+++ /dev/null
@@ -1,87 +0,0 @@
-require 'cases/helper'
-
-if mysql_56?
-  class DateTimeTest < ActiveRecord::TestCase
-    self.use_transactional_fixtures = false
-
-    class Foo < ActiveRecord::Base; end
-
-    def test_default_datetime_precision
-      ActiveRecord::Base.connection.create_table(:foos, force: true)
-      ActiveRecord::Base.connection.add_column :foos, :created_at, :datetime
-      ActiveRecord::Base.connection.add_column :foos, :updated_at, :datetime
-      assert_nil activerecord_column_option('foos', 'created_at', 'precision')
-    end
-
-    def test_datetime_data_type_with_precision
-      ActiveRecord::Base.connection.create_table(:foos, force: true)
-      ActiveRecord::Base.connection.add_column :foos, :created_at, :datetime, precision: 1
-      ActiveRecord::Base.connection.add_column :foos, :updated_at, :datetime, precision: 5
-      assert_equal 1, activerecord_column_option('foos', 'created_at', 'precision')
-      assert_equal 5, activerecord_column_option('foos', 'updated_at', 'precision')
-    end
-
-    def test_timestamps_helper_with_custom_precision
-      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-        t.timestamps null: true, precision: 4
-      end
-      assert_equal 4, activerecord_column_option('foos', 'created_at', 'precision')
-      assert_equal 4, activerecord_column_option('foos', 'updated_at', 'precision')
-    end
-
-    def test_passing_precision_to_datetime_does_not_set_limit
-      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-        t.timestamps null: true, precision: 4
-      end
-      assert_nil activerecord_column_option('foos', 'created_at', 'limit')
-      assert_nil activerecord_column_option('foos', 'updated_at', 'limit')
-    end
-
-    def test_invalid_datetime_precision_raises_error
-      assert_raises ActiveRecord::ActiveRecordError do
-        ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-          t.timestamps null: true, precision: 7
-        end
-      end
-    end
-
-    def test_mysql_agrees_with_activerecord_about_precision
-      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-        t.timestamps null: true, precision: 4
-      end
-      assert_equal 4, mysql_datetime_precision('foos', 'created_at')
-      assert_equal 4, mysql_datetime_precision('foos', 'updated_at')
-    end
-
-    def test_formatting_datetime_according_to_precision
-      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-        t.datetime :created_at, precision: 0
-        t.datetime :updated_at, precision: 4
-      end
-      date = ::Time.utc(2014, 8, 17, 12, 30, 0, 999999)
-      Foo.create!(created_at: date, updated_at: date)
-      assert foo = Foo.find_by(created_at: date)
-      assert_equal date.to_s, foo.created_at.to_s
-      assert_equal date.to_s, foo.updated_at.to_s
-      assert_equal 000000, foo.created_at.usec
-      assert_equal 999900, foo.updated_at.usec
-    end
-
-    private
-
-    def mysql_datetime_precision(table_name, column_name)
-      results = ActiveRecord::Base.connection.exec_query("SELECT column_name, datetime_precision FROM information_schema.columns WHERE table_name = '#{table_name}'")
-      result = results.find do |result_hash|
-        result_hash["column_name"] == column_name
-      end
-      result && result["datetime_precision"]
-    end
-
-    def activerecord_column_option(tablename, column_name, option)
-      result = ActiveRecord::Base.connection.columns(tablename).find do |column|
-        column.name == column_name
-      end
-      result && result.send(option)
-    end
-  end
-end
diff --git a/activerecord/test/cases/adapters/mysql2/datetime_test.rb b/activerecord/test/cases/adapters/mysql2/datetime_test.rb
deleted file mode 100644
index 7a37247d6a..0000000000
--- a/activerecord/test/cases/adapters/mysql2/datetime_test.rb
+++ /dev/null
@@ -1,84 +0,0 @@
-require 'cases/helper'
-
-if mysql_56?
-  class DateTimeTest < ActiveRecord::TestCase
-    self.use_transactional_fixtures = false
-
-    teardown do
-      ActiveRecord::Base.connection.drop_table(:foos, if_exists: true)
-    end
-
-    class Foo < ActiveRecord::Base; end
-
-    def test_datetime_data_type_with_precision
-      ActiveRecord::Base.connection.create_table(:foos, force: true)
-      ActiveRecord::Base.connection.add_column :foos, :created_at, :datetime, precision: 1
-      ActiveRecord::Base.connection.add_column :foos, :updated_at, :datetime, precision: 5
-      assert_equal 1, activerecord_column_option('foos', 'created_at', 'precision')
-      assert_equal 5, activerecord_column_option('foos', 'updated_at', 'precision')
-    end
-
-    def test_timestamps_helper_with_custom_precision
-      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-        t.timestamps null: true, precision: 4
-      end
-      assert_equal 4, activerecord_column_option('foos', 'created_at', 'precision')
-      assert_equal 4, activerecord_column_option('foos', 'updated_at', 'precision')
-    end
-
-    def test_passing_precision_to_datetime_does_not_set_limit
-      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-        t.timestamps null: true, precision: 4
-      end
-      assert_nil activerecord_column_option('foos', 'created_at', 'limit')
-      assert_nil activerecord_column_option('foos', 'updated_at', 'limit')
-    end
-
-    def test_invalid_datetime_precision_raises_error
-      assert_raises ActiveRecord::ActiveRecordError do
-        ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-          t.timestamps null: true, precision: 7
-        end
-      end
-    end
-
-    def test_mysql_agrees_with_activerecord_about_precision
-      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-        t.timestamps null: true, precision: 4
-      end
-      assert_equal 4, mysql_datetime_precision('foos', 'created_at')
-      assert_equal 4, mysql_datetime_precision('foos', 'updated_at')
-    end
-
-    def test_formatting_datetime_according_to_precision
-      ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-        t.datetime :created_at, precision: 0
-        t.datetime :updated_at, precision: 4
-      end
-      date = ::Time.utc(2014, 8, 17, 12, 30, 0, 999999)
-      Foo.create!(created_at: date, updated_at: date)
-      assert foo = Foo.find_by(created_at: date)
-      assert_equal date.to_s, foo.created_at.to_s
-      assert_equal date.to_s, foo.updated_at.to_s
-      assert_equal 000000, foo.created_at.usec
-      assert_equal 999900, foo.updated_at.usec
-    end
-
-    private
-
-    def mysql_datetime_precision(table_name, column_name)
-      results = ActiveRecord::Base.connection.exec_query("SELECT column_name, datetime_precision FROM information_schema.columns WHERE table_name = '#{table_name}'")
-      result = results.find do |result_hash|
-        result_hash["column_name"] == column_name
-      end
-      result && result["datetime_precision"]
-    end
-
-    def activerecord_column_option(tablename, column_name, option)
-      result = ActiveRecord::Base.connection.columns(tablename).find do |column|
-        column.name == column_name
-      end
-      result && result.send(option)
-    end
-  end
-end
diff --git a/activerecord/test/cases/adapters/postgresql/timestamp_test.rb b/activerecord/test/cases/adapters/postgresql/timestamp_test.rb
index 3091ee136f..da14063e20 100644
--- a/activerecord/test/cases/adapters/postgresql/timestamp_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/timestamp_test.rb
@@ -1,5 +1,4 @@
 require 'cases/helper'
-require 'support/schema_dumping_helper'
 require 'models/developer'
 require 'models/topic'
 
@@ -89,102 +88,3 @@ class TimestampTest < ActiveRecord::TestCase
     assert_equal date, Developer.find_by_name("yahagi").updated_at
   end
 end
-
-class TimestampPrecisionTest < ActiveRecord::TestCase
-  include SchemaDumpingHelper
-  self.use_transactional_fixtures = false
-
-  class Foo < ActiveRecord::Base; end
-
-  teardown do
-    ActiveRecord::Base.connection.drop_table(:foos, if_exists: true)
-  end
-
-  def test_default_datetime_precision
-    ActiveRecord::Base.connection.create_table(:foos)
-    ActiveRecord::Base.connection.add_column :foos, :created_at, :datetime
-    ActiveRecord::Base.connection.add_column :foos, :updated_at, :datetime
-    assert_nil activerecord_column_option('foos', 'created_at', 'precision')
-  end
-
-  def test_timestamp_data_type_with_precision
-    ActiveRecord::Base.connection.create_table(:foos)
-    ActiveRecord::Base.connection.add_column :foos, :created_at, :datetime, :precision => 0
-    ActiveRecord::Base.connection.add_column :foos, :updated_at, :datetime, :precision => 5
-    assert_equal 0, activerecord_column_option('foos', 'created_at', 'precision')
-    assert_equal 5, activerecord_column_option('foos', 'updated_at', 'precision')
-  end
-
-  def test_timestamps_helper_with_custom_precision
-    ActiveRecord::Base.connection.create_table(:foos) do |t|
-      t.timestamps :null => true, :precision => 4
-    end
-    assert_equal 4, activerecord_column_option('foos', 'created_at', 'precision')
-    assert_equal 4, activerecord_column_option('foos', 'updated_at', 'precision')
-  end
-
-  def test_passing_precision_to_timestamp_does_not_set_limit
-    ActiveRecord::Base.connection.create_table(:foos) do |t|
-      t.timestamps :null => true, :precision => 4
-    end
-    assert_nil activerecord_column_option("foos", "created_at", "limit")
-    assert_nil activerecord_column_option("foos", "updated_at", "limit")
-  end
-
-  def test_invalid_timestamp_precision_raises_error
-    assert_raises ActiveRecord::ActiveRecordError do
-      ActiveRecord::Base.connection.create_table(:foos) do |t|
-        t.timestamps :null => true, :precision => 7
-      end
-    end
-  end
-
-  def test_postgres_agrees_with_activerecord_about_precision
-    ActiveRecord::Base.connection.create_table(:foos) do |t|
-      t.timestamps :null => true, :precision => 4
-    end
-    assert_equal '4', pg_datetime_precision('foos', 'created_at')
-    assert_equal '4', pg_datetime_precision('foos', 'updated_at')
-  end
-
-  def test_formatting_timestamp_according_to_precision
-    ActiveRecord::Base.connection.create_table(:foos, force: true) do |t|
-      t.datetime :created_at, precision: 0
-      t.datetime :updated_at, precision: 4
-    end
-    date = ::Time.utc(2014, 8, 17, 12, 30, 0, 999999)
-    Foo.create!(created_at: date, updated_at: date)
-    assert foo = Foo.find_by(created_at: date)
-    assert_equal 1, Foo.where(updated_at: date).count
-    assert_equal date.to_s, foo.created_at.to_s
-    assert_equal date.to_s, foo.updated_at.to_s
-    assert_equal 000000, foo.created_at.usec
-    assert_equal 999900, foo.updated_at.usec
-  end
-
-  def test_datetime_precision_with_zero_should_be_dumped
-    ActiveRecord::Base.connection.create_table(:foos) do |t|
-      t.timestamps precision: 0
-    end
-    output = dump_table_schema("foos")
-    assert_match %r{t\.datetime\s+"created_at",\s+precision: 0,\s+null: false$}, output
-    assert_match %r{t\.datetime\s+"updated_at",\s+precision: 0,\s+null: false$}, output
-  end
-
-  private
-
-  def pg_datetime_precision(table_name, column_name)
-    results = ActiveRecord::Base.connection.execute("SELECT column_name, datetime_precision FROM information_schema.columns WHERE table_name ='#{table_name}'")
-    result = results.find do |result_hash|
-      result_hash["column_name"] == column_name
-    end
-    result && result["datetime_precision"]
-  end
-
-  def activerecord_column_option(tablename, column_name, option)
-    result = ActiveRecord::Base.connection.columns(tablename).find do |column|
-      column.name == column_name
-    end
-    result && result.send(option)
-  end
-end
diff --git a/activerecord/test/cases/date_time_precision_test.rb b/activerecord/test/cases/date_time_precision_test.rb
new file mode 100644
index 0000000000..720f10a9d3
--- /dev/null
+++ b/activerecord/test/cases/date_time_precision_test.rb
@@ -0,0 +1,102 @@
+require 'cases/helper'
+require 'support/schema_dumping_helper'
+
+if ActiveRecord::Base.connection.supports_datetime_with_precision?
+class DateTimePrecisionTest < ActiveRecord::TestCase
+  include SchemaDumpingHelper
+  self.use_transactional_fixtures = false
+
+  class Foo < ActiveRecord::Base; end
+
+  setup do
+    @connection = ActiveRecord::Base.connection
+  end
+
+  teardown do
+    @connection.drop_table :foos, if_exists: true
+  end
+
+  def test_datetime_data_type_with_precision
+    @connection.create_table(:foos, force: true)
+    @connection.add_column :foos, :created_at, :datetime, precision: 0
+    @connection.add_column :foos, :updated_at, :datetime, precision: 5
+    assert_equal 0, activerecord_column_option('foos', 'created_at', 'precision')
+    assert_equal 5, activerecord_column_option('foos', 'updated_at', 'precision')
+  end
+
+  def test_timestamps_helper_with_custom_precision
+    @connection.create_table(:foos, force: true) do |t|
+      t.timestamps precision: 4
+    end
+    assert_equal 4, activerecord_column_option('foos', 'created_at', 'precision')
+    assert_equal 4, activerecord_column_option('foos', 'updated_at', 'precision')
+  end
+
+  def test_passing_precision_to_datetime_does_not_set_limit
+    @connection.create_table(:foos, force: true) do |t|
+      t.timestamps precision: 4
+    end
+    assert_nil activerecord_column_option('foos', 'created_at', 'limit')
+    assert_nil activerecord_column_option('foos', 'updated_at', 'limit')
+  end
+
+  def test_invalid_datetime_precision_raises_error
+    assert_raises ActiveRecord::ActiveRecordError do
+      @connection.create_table(:foos, force: true) do |t|
+        t.timestamps precision: 7
+      end
+    end
+  end
+
+  def test_database_agrees_with_activerecord_about_precision
+    @connection.create_table(:foos, force: true) do |t|
+      t.timestamps precision: 4
+    end
+    assert_equal 4, database_datetime_precision('foos', 'created_at')
+    assert_equal 4, database_datetime_precision('foos', 'updated_at')
+  end
+
+  def test_formatting_datetime_according_to_precision
+    @connection.create_table(:foos, force: true) do |t|
+      t.datetime :created_at, precision: 0
+      t.datetime :updated_at, precision: 4
+    end
+    date = ::Time.utc(2014, 8, 17, 12, 30, 0, 999999)
+    Foo.create!(created_at: date, updated_at: date)
+    assert foo = Foo.find_by(created_at: date)
+    assert_equal 1, Foo.where(updated_at: date).count
+    assert_equal date.to_s, foo.created_at.to_s
+    assert_equal date.to_s, foo.updated_at.to_s
+    assert_equal 000000, foo.created_at.usec
+    assert_equal 999900, foo.updated_at.usec
+  end
+
+  if current_adapter?(:PostgreSQLAdapter)
+    def test_datetime_precision_with_zero_should_be_dumped
+      @connection.create_table(:foos) do |t|
+        t.timestamps precision: 0
+      end
+      output = dump_table_schema("foos")
+      assert_match %r{t\.datetime\s+"created_at",\s+precision: 0,\s+null: false$}, output
+      assert_match %r{t\.datetime\s+"updated_at",\s+precision: 0,\s+null: false$}, output
+    end
+  end
+
+  private
+
+  def database_datetime_precision(table_name, column_name)
+    results = @connection.exec_query("SELECT column_name, datetime_precision FROM information_schema.columns WHERE table_name = '#{table_name}'")
+    result = results.find do |result_hash|
+      result_hash["column_name"] == column_name
+    end
+    result && result["datetime_precision"].to_i
+  end
+
+  def activerecord_column_option(tablename, column_name, option)
+    result = @connection.columns(tablename).find do |column|
+      column.name == column_name
+    end
+    result && result.send(option)
+  end
+end
+end