mysqli union以正确的列名获取数据

g6baxovj 于 2021-06-19 发布在 Mysql

关注(0)|答案(2)|浏览(344)

我想用union从数据库中获取数据，我将link定义为newslink，pic定义为articlepic，但它在newslink列下显示articlepic数据，如何解决这个问题？

SELECT * FROM
((SELECT date, link as newslink FROM news ORDER BY id DESC)
UNION
(SELECT date, pic as articlepic FROM article ORDER BY id DESC)) as x
ORDER BY date DESC LIMIT 6

样本数据
我想在articlepic列下获取articlepic数据，在newslink列下获取newslink数据

mysql union

来源：https://stackoverflow.com/questions/52386776/mysqli-union-get-data-in-correct-column-name

2条答案

按热度按时间

vc9ivgsu1#

在查询中使用union时，无法获取列的其他名称

SELECT * FROM
    (
        (
        SELECT
            DATE,
            link AS newslink,
            '-'  As articlepic         
        FROM news ORDER BY id DESC
    ) UNION (
    SELECT
        DATE,
        '-'  As newslink,         
        pic AS articlepic
    FROM article ORDER BY id DESC
)
    ) AS X
ORDER BY DATE DESC LIMIT 6

赞(0）回复(0）举报 2021-06-20

lymgl2op2#

如果在不同的列中输入值，则必须在select中为不对应的列添加null值

SELECT * FROM
 ((SELECT date, link as newslink, null as articlepic 
  FROM news ORDER BY id DESC)
UNION
 (SELECT date, null, pic 
   FROM article ORDER BY id DESC)) as x
ORDER BY date DESC LIMIT 6

赞(0）回复(0）举报 2021-06-20

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mysqli union以正确的列名获取数据

2条答案

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