1.去空格函数
参考:https://jingyan.baidu.com/article/9c69d48f91da1313c8024e4e.html
1.1去除左边空格LTRIM()
select '('+' happy '+')' as '左边有四空格字符串','('+LTRIM(' happy ')+')' as '去除左边空格';
select '('+' happy '+')' as '左边有一空格字符串','('+LTRIM(' happy ')+')' as '去除左边空格';
1.2去除右边空格RTRIM()
select '('+' happy '+')' as '右边有一空格字符串','('+RTRIM(' happy ')+')' as '去除右边空格';
select '('+' happy '+')' as '右边有四空格字符串','('+RTRIM(' happy ')+')' as '去除右边空格';
2.判断是否为空isnull()
isnull(value1,value2)
1、value1与value2的数据类型必须一致。
2、如果value1的值不为null,结果返回value1。
3、如果value1为null,结果返回vaule2的值。vaule2是你设定的值。
示例
declare @name nvarchar(50)
select isnull(@name,'空')as name
set @name='晓敏'
select isnull(@name,'空')as name
2.2也可以判断字符串的长度
--也可以判断字符串的长度
declare @name nvarchar(50)
set @name='1'
select len(@name) as 'name的长度'
set @name='12'
select len(@name) as 'name的长度'
set @name='123'
select len(@name) as 'name的长度'
set @name='CPLVFX'
select len(@name) as 'name的长度'
set @name='橙'
select len(@name) as 'name的长度'