1 files changed, 125 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb b/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb
new file mode 100644
index 0000000000..13c9b6cbd9
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb
@@ -0,0 +1,125 @@
+module ActiveRecord
+  module ConnectionAdapters
+    module MySQL
+      module DatabaseStatements
+        # Returns an ActiveRecord::Result instance.
+        def select_all(arel, name = nil, binds = [], preparable: nil)
+          result = if ExplainRegistry.collect? && prepared_statements
+            unprepared_statement { super }
+          else
+            super
+          end
+          @connection.next_result while @connection.more_results?
+          result
+        end
+
+        # Returns a record hash with the column names as keys and column values
+        # as values.
+        def select_one(arel, name = nil, binds = [])
+          arel, binds = binds_from_relation(arel, binds)
+          @connection.query_options.merge!(as: :hash)
+          select_result(to_sql(arel, binds), name, binds) do |result|
+            @connection.next_result while @connection.more_results?
+            result.first
+          end
+        ensure
+          @connection.query_options.merge!(as: :array)
+        end
+
+        # Returns an array of arrays containing the field values.
+        # Order is the same as that returned by +columns+.
+        def select_rows(sql, name = nil, binds = [])
+          select_result(sql, name, binds) do |result|
+            @connection.next_result while @connection.more_results?
+            result.to_a
+          end
+        end
+
+        # Executes the SQL statement in the context of this connection.
+        def execute(sql, name = nil)
+          if @connection
+            # make sure we carry over any changes to ActiveRecord::Base.default_timezone that have been
+            # made since we established the connection
+            @connection.query_options[:database_timezone] = ActiveRecord::Base.default_timezone
+          end
+
+          super
+        end
+
+        def exec_query(sql, name = 'SQL', binds = [], prepare: false)
+          if without_prepared_statement?(binds)
+            execute_and_free(sql, name) do |result|
+              ActiveRecord::Result.new(result.fields, result.to_a) if result
+            end
+          else
+            exec_stmt_and_free(sql, name, binds, cache_stmt: prepare) do |_, result|
+              ActiveRecord::Result.new(result.fields, result.to_a) if result
+            end
+          end
+        end
+
+        def exec_delete(sql, name, binds)
+          if without_prepared_statement?(binds)
+            execute_and_free(sql, name) { @connection.affected_rows }
+          else
+            exec_stmt_and_free(sql, name, binds) { |stmt| stmt.affected_rows }
+          end
+        end
+        alias :exec_update :exec_delete
+
+        protected
+
+        def last_inserted_id(result)
+          @connection.last_id
+        end
+
+        private
+
+        def select_result(sql, name = nil, binds = [])
+          if without_prepared_statement?(binds)
+            execute_and_free(sql, name) { |result| yield result }
+          else
+            exec_stmt_and_free(sql, name, binds, cache_stmt: true) { |_, result| yield result }
+          end
+        end
+
+        def exec_stmt_and_free(sql, name, binds, cache_stmt: false)
+          if @connection
+            # make sure we carry over any changes to ActiveRecord::Base.default_timezone that have been
+            # made since we established the connection
+            @connection.query_options[:database_timezone] = ActiveRecord::Base.default_timezone
+          end
+
+          type_casted_binds = binds.map { |attr| type_cast(attr.value_for_database) }
+
+          log(sql, name, binds) do
+            if cache_stmt
+              cache = @statements[sql] ||= {
+                stmt: @connection.prepare(sql)
+              }
+              stmt = cache[:stmt]
+            else
+              stmt = @connection.prepare(sql)
+            end
+
+            begin
+              result = stmt.execute(*type_casted_binds)
+            rescue Mysql2::Error => e
+              if cache_stmt
+                @statements.delete(sql)
+              else
+                stmt.close
+              end
+              raise e
+            end
+
+            ret = yield stmt, result
+            result.free if result
+            stmt.close unless cache_stmt
+            ret
+          end
+        end
+      end
+    end
+  end
+end