sql like语句通配符百分号、下划线与escape用法

在sql查询中，像*和?，sql的like语句中，使用%和_来表明任意多个字符和一个字符 

# %表明任意多个字符  

select * from user where username like '%huxiao';  
select * from user where username like 'huxiao%';  
select * from user where username like '%huxiao%';  
  
# %表明一个字符  
select * from user where username like '_'; 
select * from user where username like '______'; 
select * from user where username like 'huxia_';
select * from user where username like 'h_xiao';  
  
# 要查%或者_，的话？使用escape，转义字符 后面的%或_就不做为通配符了，注意前面没有转义字符的%和_仍然起通配符做用  
select username from gg_user where username like '%xiao/_%' escape '/';  
select username from gg_user where username like '%xiao/%%' escape '/';