sql - 选择语句抛出 "ORA-00907: missing right parenthesis"

Question

我对 Oracle 有点陌生，似乎无法运行下面的查询。

SELECT user_key AS oldKey,
       (SELECT 
            user_key
        FROM
            user_mapping AS u
        WHERE lower(u.username) = u.lower_username
          AND lower(u.username) = lower(um.username)
        ) AS newKey,
       um.username,
       um.lower_username
  FROM user_mapping AS um
  WHERE user_key IN (SELECT user_key
                      FROM user_mapping
                      WHERE (lower(username) != lower_username))
                         OR (lower_username is null)

它抛出“ORA-00907:缺少右括号”错误，但我没有看到任何语法错误，当我针对 MySQL 数据库运行查询时，查询工作正常。

正在检查与缺少括号相关的其他一些问题，但主要是关于未明确说明主键或将某些内容指定为非空，但我认为这似乎也不是这里的问题。

如果我在上面的任何地方遗漏或错误，请告诉我。

谢谢。

Answer 1

您在第 14 行有一个额外的 ) 而您在末尾(即第 15 行之后)缺少了一个 )。

我已经解决了这两个问题。尝试以下操作

SELECT user_key AS oldKey,
       (SELECT 
            user_key
        FROM
            user_mapping AS u
        WHERE lower(u.username) = u.lower_username
          AND lower(u.username) = lower(um.username)
        ) AS newKey,
       um.username,
       um.lower_username
  FROM user_mapping AS um
  WHERE user_key IN ( SELECT user_key
                      FROM user_mapping
                      WHERE (lower(username) != lower_username)
                         OR (lower_username is null)
                    )