Question

有人可以帮我这个，我有2张桌子

financeaccountcurrencymapping和ownedaccount。

我想选择那些其领域为legalEntity_id的financeaccountcurrencymapping。

这是我到目前为止所拥有的。

SELECT 
FROM financeaccountcurrencymapping 
WHERE ownedAccount_id EXISTS IN (
                SELECT id 
                FROM ownedaccount 
                WHERE legalEntity_id = ??);

表格中的字段为：

'financeaccountcurrencymapping'

id
moneyCurrency
accountForCash_id
ownedAccount_id

'ownedaccount'

ID
名称
legalEntity_id
assetOrLiability
assetType
depositoryType
liabilityType
multipleCurrency
货币
描述

Answer 1

在这种情况下你不会使用EXISTS。单独使用就可以了。

SELECT 
FROM financeaccountcurrencymapping 
WHERE ownedAccount_id IN (SELECT id FROM ownedaccount WHERE legalEntity_id = ??);

Answer 2

SELECT legalEntity_id
FROM financeaccountcurrencymapping 
WHERE ownedAccount_id IN (
                SELECT id 
                FROM ownedaccount 
                WHERE legalEntity_id = ??);

Answer 3

你原来的查询非常接近。您只需删除EXISTS，就像这样：

SELECT *
FROM financeaccountcurrencymapping 
WHERE ownedAccount_id IN (
                SELECT id 
                FROM ownedaccount 
                WHERE legalEntity_id = ??);

或者，您可以使用JOIN编写此查询以获得相同的有效结果。

SELECT f.*
FROM financeaccountcurrencymapping AS f 
INNER JOIN ownedaccount AS o ON (f.id = o.ownedAccount_id) 
WHERE o.legalEntity_id = ??;

Answer 4

如果你真的想使用EXISTS或想看一个如何使用EXISTS的例子，我认为以下内容可行。我个人可能会改用IN。

SELECT 
FROM financeaccountcurrencymapping as f
WHERE EXISTS (SELECT id 
              FROM ownedaccount 
              WHERE f.ownedAccount_id = id AND legalEntity_id = ??);

EXISTS IN查询怎么样？

4 个答案: