如何使用带有行号的mysql分区按类型返回项

CREATE TABLE my_table (
  id INT AUTO_INCREMENT,
  type VARCHAR(50),
  data VARCHAR(100),
  PRIMARY KEY (id, type)
)
PARTITION BY LIST COLUMNS (type) (
  PARTITION p1 VALUES IN ('type1'),
  PARTITION p2 VALUES IN ('type2'),
  PARTITION p3 VALUES IN ('type3')
);

INSERT INTO my_table (type, data) VALUES ('type1', 'data1');
INSERT INTO my_table (type, data) VALUES ('type2', 'data2');
INSERT INTO my_table (type, data) VALUES ('type3', 'data3');

SELECT 
  @row_number:=CASE
    WHEN @type = type THEN @row_number + 1
    ELSE 1
  END AS row_number,
  @type:=type AS type,
  data
FROM
  (SELECT @row_number:=0, @type:='') AS t,
  my_table
ORDER BY type, id;