Ensure that microsecond precision is only used for version of mysql that support it. Fixes #19711

3 files changed, 37 insertions, 1 deletions

diff --git a/activerecord/test/cases/adapters/mysql/quoting_test.rb b/activerecord/test/cases/adapters/mysql/quoting_test.rb
index a296cf9d31..ca476947fc 100644
--- a/activerecord/test/cases/adapters/mysql/quoting_test.rb
+++ b/activerecord/test/cases/adapters/mysql/quoting_test.rb
@@ -12,4 +12,18 @@ class MysqlQuotingTest < ActiveRecord::MysqlTestCase
   def test_type_cast_false
     assert_equal 0, @conn.type_cast(false)
   end
+
+  def test_quoted_date_precision_for_gte_564
+    @conn.stubs(:full_version).returns('5.6.4')
+    @conn.remove_instance_variable(:@version)
+    t = Time.now.change(usec: 1)
+    assert_match(/\.000001\z/, @conn.quoted_date(t))
+  end
+
+  def test_quoted_date_precision_for_lt_564
+    @conn.stubs(:full_version).returns('5.6.3')
+    @conn.remove_instance_variable(:@version)
+    t = Time.now.change(usec: 1)
+    refute_match(/\.000001\z/, @conn.quoted_date(t))
+  end
 end
diff --git a/activerecord/test/cases/adapters/mysql2/quoting_test.rb b/activerecord/test/cases/adapters/mysql2/quoting_test.rb
new file mode 100644
index 0000000000..a49cbba4b4
--- /dev/null
+++ b/activerecord/test/cases/adapters/mysql2/quoting_test.rb
@@ -0,0 +1,21 @@
+require "cases/helper"
+
+class Mysql2QuotingTest < ActiveRecord::Mysql2TestCase
+  setup do
+    @connection = ActiveRecord::Base.connection
+  end
+
+  test 'quoted date precision for gte 5.6.4' do
+    @connection.stubs(:full_version).returns('5.6.4')
+    @connection.remove_instance_variable(:@version)
+    t = Time.now.change(usec: 1)
+    assert_match(/\.000001\z/, @connection.quoted_date(t))
+  end
+
+  test 'quoted date precision for lt 5.6.4' do
+    @connection.stubs(:full_version).returns('5.6.3')
+    @connection.remove_instance_variable(:@version)
+    t = Time.now.change(usec: 1)
+    refute_match(/\.000001\z/, @connection.quoted_date(t))
+  end
+end
diff --git a/activerecord/test/cases/helper.rb b/activerecord/test/cases/helper.rb
index 12c793c408..d9d0f929db 100644
--- a/activerecord/test/cases/helper.rb
+++ b/activerecord/test/cases/helper.rb
@@ -47,7 +47,8 @@ end
 
 def mysql_56?
   current_adapter?(:MysqlAdapter, :Mysql2Adapter) &&
-    ActiveRecord::Base.connection.send(:version).join(".") >= "5.6.0"
+    ActiveRecord::Base.connection.send(:version) >= '5.6.0' &&
+    ActiveRecord::Base.connection.send(:version) < '5.7.0'
 end
 
 def mysql_enforcing_gtid_consistency?