行转列例子

create table test.t_20210429
(
app    String,
cnt Nullable(UInt32),
per Nullable(UInt32)
)
ENGINE=MergeTree()
order by app;

insert into test.t_20210429 values(‘a‘,100,200),(‘a‘,50,123),(‘b‘,1,1);
-------------------------------------------------------------------------------------------------------------
SELECT
    c1,c2
FROM 
(
    SELECT groupArray([cnt, per])[1] AS arr_1,[‘cc1‘, ‘cc2‘] AS arr_2
    FROM 
    (
        SELECT sum(cnt) AS cnt,sum(per) AS per
        FROM test.t_20210429
        WHERE app = ‘a‘
        GROUP BY app
    ) AS A
) AS B
ARRAY JOIN
    arr_1 AS c1,
    arr_2 AS c2
 ;