Cache full MySQL version in schema cache

  * The database version is cached in all the adapters, but this didn't include
    the full MySQL version. Anything that uses the full MySQL version would need
    to query the database to get that data even if they're using the schema
    cache.
  * Now the full MySQL version will be cached in the schema cache via the
    Version object.

4 files changed, 25 insertions, 6 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
index 200184c2f9..bf0bb84c93 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -170,8 +170,11 @@ module ActiveRecord
       class Version
         include Comparable
 
-        def initialize(version_string)
+        attr_reader :full_version_string
+
+        def initialize(version_string, full_version_string = nil)
           @version = version_string.split(".").map(&:to_i)
+          @full_version_string = full_version_string
         end
 
         def <=>(version_string)
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
index ca8bbc14da..75bc94c49c 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb
@@ -51,12 +51,20 @@ module ActiveRecord
           end
       end
 
+      class Version < AbstractAdapter::Version # :nodoc:
+        def initialize(version_string, full_version_string)
+          super
+        end
+      end
+
       def initialize(connection, logger, connection_options, config)
         super(connection, logger, config)
       end
 
       def get_database_version #:nodoc:
-        Version.new(version_string)
+        full_version_string = get_full_version
+        version_string = version_string(full_version_string)
+        Version.new(version_string, full_version_string)
       end
 
       def mariadb? # :nodoc:
@@ -801,8 +809,8 @@ module ActiveRecord
           MismatchedForeignKey.new(options)
         end
 
-        def version_string
-          full_version.match(/^(?:5\.5\.5-)?(\d+\.\d+\.\d+)/)[1]
+        def version_string(full_version_string) # :nodoc:
+          full_version_string.match(/^(?:5\.5\.5-)?(\d+\.\d+\.\d+)/)[1]
         end
 
         class MysqlString < Type::String # :nodoc:
diff --git a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
index 0dc880c731..2ff411a058 100644
--- a/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb
@@ -125,8 +125,12 @@ module ActiveRecord
           super
         end
 
-        def full_version
-          @full_version ||= @connection.server_info[:version]
+        def full_version # :nodoc:
+          schema_cache.database_version.full_version_string
+        end
+
+        def get_full_version # :nodoc:
+          @connection.server_info[:version]
         end
     end
   end
diff --git a/activerecord/test/cases/connection_adapters/schema_cache_test.rb b/activerecord/test/cases/connection_adapters/schema_cache_test.rb
index 89a9c30f9b..28e232b88f 100644
--- a/activerecord/test/cases/connection_adapters/schema_cache_test.rb
+++ b/activerecord/test/cases/connection_adapters/schema_cache_test.rb
@@ -95,6 +95,10 @@ module ActiveRecord
 
         assert_no_queries do
           assert_equal @database_version.to_s, @cache.database_version.to_s
+
+          if current_adapter?(:Mysql2Adapter)
+            assert_not_nil @cache.database_version.full_version_string
+          end
         end
       end