SQL中isnull函數的用法

原創 yanpingsz 2020-05-31 20:26

語法：

   isnull(check_expression,replacement_expression)

 

參數check_expression與replacement_expression類型需相同

 

返回值：

   若check_expression爲null，則返回replacement_expression

   若check_expression不爲null，則返回check_expression

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