MySQL-大小写条件错误

Question

我在 MySQL 中遇到以下 Case 语句的问题:

CASE  
    WHEN 
    ((SUBSTRING_INDEX('Provider - Remote Client - North', '-', -2) = ('Provider - Remote Client - North')) then SUBSTRING_INDEX('Provider - Remote Client - North', '-', -1)
    ELSE SUBSTRING_INDEX('Provider - Remote Client - North', '-', -2)
END CASE

我收到“意外”错误有人可以建议吗？!？谢谢

Answer 1

WHEN 中有一个括号，并且 END 之后有一个额外的 CASE:

CASE  
    WHEN 
      SUBSTRING_INDEX('Provider - Remote Client - North', '-', -2) = 'Provider - Remote Client - North'
    THEN SUBSTRING_INDEX('Provider - Remote Client - North', '-', -1)
    ELSE SUBSTRING_INDEX('Provider - Remote Client - North', '-', -2)
END