-- 步骤1: 定义两个参数SELECTNULLIF(Column1,Column2)ASResultFROMMyTableWHEREColumn1ISNOTNULLANDColumn2ISNOTNULL;-- 防止类型错误的高级命令高级命令```sqlSELECTNULLIF(CAST(Column1ASVARCHAR(50)),CAST(Column2ASVARCHAR(50)))ASResultFROMMyTable; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. #...
sql server nullif 函数 sql null用法 目标:辨别并使用Null值 反模式:将Null值作为普通的值,反之亦然 1、在表达式中使用Null: Null值与空字符串是不一样的,Null值参与任何的加、减、乘、除等其他运算,结果都是Null; Null值与False也不同。And、Or和Not三个bool操作如果设计Null,结果很迷惑。 2、搜索运行为...
NULLIF 用于检查两个表达式,语法: NULLIF(expression, expression) 如果两个 expression 相等,则返回 NULL,该 NULL 为第一个 expression 的数据类型 如果两个 expression 不相等,则返回第一个 expression Sql Server中两个判断是否为空的函数NULLIF和ISNULL的说明如下: NULLIF:需要两个参数,如果两个指定的表达式等价,...
NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL. We recommend that you not use time-dependent functions, such as RAND(), within a NULLIF function. This could cause the function to be evaluated twice and to return...
在sql server中做除法处理的时候,我们经常需要处理除数为零的情况,因为如果遇到这种情况的时候,sqlserver会抛出遇到以零作除数错误的异常,我们总不希望把这个异常显示给用户吧。 做个会报这个错误的示例,如以下sql代码: declare @a int; declare @b int; ...
NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL. We recommend that you not use time-dependent functions, such as RAND(), within a NULLIF function. This could cause the function to be evaluated twice and to return...
SQL Server Management Studio 方法/步骤 1 1、ISNULL函数，判断参数是否为NULL函数格式：ISNULL(Expression1，Expression2)给定两个参数，如果Expression1是NULL，那么返回Expression2，否则返回Expression1。等价于：CASE WHEN Expression1 IS NULL THEN Expression2 ELSE Expression1 END。2 2、ISNULL函数，实际应用常用...
sql-server-ver16 Release notes Business continuity Database design Development Internals & Architecture Installation Migrate & load data Manage, monitor, & tune Query data Reporting & Analytics Security Tools Tutorials SQL Server on Linux SQL on Azure ...
NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL. We recommend that you not use time-dependent functions, such as RAND(), within a NULLIF function. This could cause the function to be evaluated twice and to return...
NULLIF is equivalent to a searched CASE expression in which the two expressions are equal and the resulting expression is NULL. We recommend that you not use time-dependent functions, such as RAND(), within a NULLIF function. This could cause the function to be evaluated twice and to return...