小编yos*_*shi的帖子

执行WITH ROLLUP多字段分组时，MySQL 会为每个组返回一个汇总行，以及总体摘要：

CREATE TABLE test (name VARCHAR(50), number TINYINT);
INSERT INTO test VALUES
    ('foo', 1), ('foo', 1), ('foo', 2), ('foo', 3), ('foo', 3),
    ('bar', 1), ('bar', 2), ('bar', 2), ('bar', 2), ('bar', 3),
    ('baz', 1), ('baz', 2), ('bar', 2);
SELECT name, number, COUNT(1) FROM test GROUP BY name, number WITH ROLLUP;

+------+--------+----------+
| name | number | count(1) |
+------+--------+----------+
| bar  |      1 |        1 |
| bar  |      2 |        3 |
| bar  | …