将大写字符数据转换为小写字符数据后返回字符表达式。

语法

LOWER ( character_expression )

参数

character_expression

是字符或二进制数据表达式。character_expression 可以是常量、变量或列。character_expression 必须是可以隐性转换为 varchar 的数据类型。否则，使用 CAST 显式转换 character_expression。

返回类型

varchar

示例

下例在选择价格位于 $11 和 $20 间的书名时，使用 LOWER 函数、UPPER 函数并把 UPPER 函数嵌套在 LOWER 函数内。

USE pubs
GO
SELECT LOWER(SUBSTRING(title, 1, 20)) AS Lower, 
   UPPER(SUBSTRING(title, 1, 20)) AS Upper, 
   LOWER(UPPER(SUBSTRING(title, 1, 20))) As LowerUpper
FROM titles
WHERE price between 11.00 and 20.00
GO

下面是结果集：

Lower                   Upper                   LowerUpper           
--------------------    --------------------    -------------------- 
the busy executive's    THE BUSY EXECUTIVE'S    the busy executive's 
cooking with compute    COOKING WITH COMPUTE    cooking with compute 
straight talk about     STRAIGHT TALK ABOUT     straight talk about  
silicon valley gastr    SILICON VALLEY GASTR    silicon valley gastr 
secrets of silicon v    SECRETS OF SILICON V    secrets of silicon v 
prolonged data depri    PROLONGED DATA DEPRI    prolonged data depri 
fifty years in bucki    FIFTY YEARS IN BUCKI    fifty years in bucki 
sushi, anyone?          SUSHI, ANYONE?          sushi, anyone?       

(8 row(s) affected)