SQL中isnull函数的用法

原創 yanpingsz 2020-05-31 20:26

语法：

   isnull(check_expression,replacement_expression)

 

参数check_expression与replacement_expression类型需相同

 

返回值：

   若check_expression为null，则返回replacement_expression

   若check_expression不为null，则返回check_expression

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