这是我的表在查询之前的样子。
cid | purl | purl_full
----------------------------
2050 | dingo | http://dingo.domain.com
2050 | wombat | http://wombat.domain.com
2050 | platypus | http://platypus.domain.com
2050 | koala | http://koala.domain.com
2050 | dingo1 | http://dingo1.domain.com
2050 | wombat1 | http://wombat1.domain.com
2050 | platypus1 | http://platypus1.domain.com
2050 | koala1 | http://koala1.domain.com
2050 | dingo | tempurl
2050 | wombat | tempurl
2050 | platypus | tempurl
2050 | koala | tempurl
这就是查询后的样子。
cid | purl | purl_full
----------------------------
2050 | dingo | http://dingo.domain.com
2050 | wombat | http://wombat.domain.com
2050 | platypus | http://platypus.domain.com
2050 | koala | http://koala.domain.com
2050 | dingo1 | http://dingo1.domain.com
2050 | wombat1 | http://wombat1.domain.com
2050 | platypus1 | http://platypus1.domain.com
2050 | koala1 | http://koala1.domain.com
2050 | dingo2 | http://dingo2.domain.com
2050 | wombat2 | http://wombat2.domain.com
2050 | platypus2 | http://platypus2.domain.com
2050 | koala2 | http://koala2.domain.com
这就是查询后的结果。
cid | purl | purl_full
----------------------------
2050 | dingo | http://dingo.domain.com
2050 | wombat | http://wombat.domain.com
2050 | platypus | http://platypus.domain.com
2050 | koala | http://koala.domain.com
2050 | dingo1 | http://dingo1.domain.com
2050 | wombat1 | http://wombat1.domain.com
2050 | platypus1 | http://platypus1.domain.com
2050 | koala1 | http://koala1.domain.com
2050 | dingo2 |
2050 | wombat2 |
2050 | platypus2 |
2050 | koala2 |
这是我正在使用的查询。
UPDATE localhost_campaigns.list_data SET
purl = (CASE
WHEN (purl = 'dingo' AND purl_full = 'tempurl' AND cid = 2050) THEN 'dingo2'
WHEN (purl = 'wombat' AND purl_full = 'tempurl' AND cid = 2050) THEN 'wombat2'
WHEN (purl = 'platypus' AND purl_full = 'tempurl' AND cid = 2050) THEN 'platypus2'
WHEN (purl = 'koala' AND purl_full = 'tempurl' AND cid = 2050) THEN 'koala2'
END),
purl_full = (CASE
WHEN (purl = 'dingo' AND purl_full = 'tempurl' AND cid = 2050) THEN 'http://dingo2.domain.com'
WHEN (purl = 'wombat' AND purl_full = 'tempurl' AND cid = 2050) THEN 'http://wombat2.domain.com'
WHEN (purl = 'platypus' AND purl_full = 'tempurl' AND cid = 2050) THEN 'http://platypus2.domain.com'
WHEN (purl = 'koala' AND purl_full = 'tempurl' AND cid = 2050) THEN 'http://koala2.domain.com'
END)
WHERE (purl IN ('dingo', 'wombat', 'platypus', 'koala') AND purl_full = 'tempurl' AND cid = 2050);
因此它会更新一个字段,但不会更新另一个字段。由于某种原因,它只是空白了第二个字段。
这更糟糕:
UPDATE localhost_campaigns.list_data SET
purl = CASE
WHEN (purl = 'dingo' AND purl_full = 'tempurl' AND cid = 2050) THEN 'dingo2'
WHEN (purl = 'wombat' AND purl_full = 'tempurl' AND cid = 2050) THEN 'wombat2'
WHEN (purl = 'platypus' AND purl_full = 'tempurl' AND cid = 2050) THEN 'platypus2'
WHEN (purl = 'koala' AND purl_full = 'tempurl' AND cid = 2050) THEN 'koala2'
END,
purl_full = CASE
WHEN (purl = 'dingo' AND purl_full = 'tempurl' AND cid = 2050) THEN 'http://dingo2.domain.com'
WHEN (purl = 'wombat' AND purl_full = 'tempurl' AND cid = 2050) THEN 'http://wombat2.domain.com'
WHEN (purl = 'platypus' AND purl_full = 'tempurl' AND cid = 2050) THEN 'http://platypus2.domain.com'
WHEN (purl = 'koala' AND purl_full = 'tempurl' AND cid = 2050) THEN 'http://koala2.domain.com'
END;
也尝试过这个,但没有成功(使 purl 成为唯一的名称)(同样,它只更新 purl,但不更新 purl_full,或者更确切地说,它更新它但使其为空):
UPDATE localhost_campaigns.list_data
SET purl = CASE purl
WHEN 'temp_dingo' THEN 'dingo'
WHEN 'temp_wombat' THEN 'wombat'
WHEN 'temp_platypus' THEN 'platypus'
WHEN 'temp_koala' THEN 'koala'
END,
purl_full = CASE purl
WHEN 'temp_dingo' THEN 'http://dingo.domain.com'
WHEN 'temp_wombat' THEN 'http://wombat.domain.com'
WHEN 'temp_platypus' THEN 'http://platypus.domain.com'
WHEN 'temp_koala' THEN 'http://koala.domain.com'
END
WHERE (purl IN ('temp_dingo', 'temp_wombat', 'temp_platypus', 'temp_koala') AND cid = 2050);
顺便问一下,它是如何进行更新的?它是否先执行第 1 列的所有操作,然后再执行第 2 列的所有操作,还是同时执行两列操作,然后转到下一条记录并同时执行两列操作?
最佳答案
这就是最终的工作结果。我需要将第二个 SET CASE 中的 purl 名称更改为要更改的名称,而不是原始名称。这样就回答了这个附带问题:一次执行一列还是一次执行一行。
UPDATE localhost_campaigns.list_data
SET purl = CASE purl
WHEN 'temp_dingo' THEN 'dingo'
WHEN 'temp_wombat' THEN 'wombat'
WHEN 'temp_platypus' THEN 'platypus'
WHEN 'temp_koala' THEN 'koala'
END,
purl_full = CASE purl
WHEN 'dingo' THEN 'http://dingo.domain.com'
WHEN 'wombat' THEN 'http://wombat.domain.com'
WHEN 'platypus' THEN 'http://platypus.domain.com'
WHEN 'koala' THEN 'http://koala.domain.com'
END
WHERE (purl IN ('temp_dingo', 'temp_wombat', 'temp_platypus', 'temp_koala') AND cid = 2050);
关于mysql - 如何使用单个 mysql 查询批量更新具有多个条件或条件的多个字段或列,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37141062/