PostgreSQL动态地将行转置为列

Question

嗨我试图使我的查询的结果动态对齐每列1行，请帮助我，如果这是可能的

例如，这是我的表

id , names , comm    , contrib
1    samp1   randtext     9
2    samp1   randtext     2
3    samp1   randtext     3 
5    samp2   randtext     4 
6    samp2   randtext     1   

然后我试图得到的结果是

names  comm1    comm2    comm3    contrib1  contrib2  contrib3 
samp1  randtext,randtext,randtext    9      , 2       , 3
samp2  randtext,randtext,            4      , 1       ,  

谢谢你的帮助。

Answer 1

我们可以使用ROW_NUMBER和pivot查询的组合：

WITH cte AS (
    SELECT *, ROW_NUMBER() OVER (PARTITION BY names ORDER BY id) rn
    FROM your_table
)

SELECT
    names,
    MAX(CASE WHEN rn = 1 THEN comm END) comm1,
    MAX(CASE WHEN rn = 2 THEN comm END) comm2,
    MAX(CASE WHEN rn = 3 THEN comm END) comm3,
    MAX(CASE WHEN rn = 1 THEN contrib END) contrib1,
    MAX(CASE WHEN rn = 2 THEN contrib END) contrib2,
    MAX(CASE WHEN rn = 3 THEN contrib END) contrib3
FROM cte
GROUP BY
    names
ORDER BY
    names;