Sql 简明教程

SQL - Logical Functions

SQL logical functions 主要用于检查(或测试)某些条件的真假。逻辑函数对对象和表达式执行逻辑运算或比较,并返回一个布尔值:

SQL logical functions are used primarily for checking (or testing) the truth of some conditions. A logical function performs a logical operation or comparison on objects and expressions and returns a boolean value −

Sr.No.

Function & Description

1

CHOSE()Returns a item from the list at the specified index value.

2

IIF()Returns a one of two values, depending on the boolean-expression.

3

NULLIF()Returns NULL if both expressions are equal.