MySQL 在 where 子句中选择查询
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MySQL select query in where clause
提问by Dinuka Thilanga
Can u correct this query? it is show some syntax error.
你能更正这个查询吗？它显示一些语法错误。
SELECT *
WHERE `id` IN (SELECT DISTINCT unit_trust_managing_company_id
FROM ut_funds
ORDER BY `company_name`)
There SELECT DISTINCT unit_trust_managing_company_id FROM ut_funds ORDER BYcompany_name` query is working properly.
有SELECT DISTINCT unit_trust_managing_company_id FROM ut_funds ORDER BYcompany_name` 查询工作正常。
回答by Gordon Linoff
You need a fromclause before the where:
from在 之前需要一个子句where：
SELECT *
FROM <some table here>
WHERE `id` IN (SELECT unit_trust_managing_company_id FROM ut_funds)
Also, the distinctand order byare not needed for the instatement.
此外，该语句不需要distinct和。order byin
回答by Cuse70
In most (all?) cases you can rewrite the query without using the query in the where clause AND get much better performance. Try something like:
在大多数（所有？）情况下，您可以在不使用 where 子句中的查询的情况下重写查询，并获得更好的性能。尝试类似：
SELECT DISTINCT t.*
FROM some_table t, ut_funds u
WHERE t.id=u.unit_trust_managing_company_id
