mysql指定字符位置截取字符串（多行重復信息進行合並）

select number ,SUBSTRING_INDEX(GROUP_CONCAT(name ORDER BY name desc ),',',1),
SUBSTRING_INDEX(GROUP_CONCAT(idcard ORDER BY name desc ),',',1),
SUBSTRING_INDEX(GROUP_CONCAT(branch ORDER BY name desc ),',',1),
SUBSTRING_INDEX(GROUP_CONCAT(department ORDER BY name desc ),',',1),
SUBSTRING_INDEX(GROUP_CONCAT(direct_superior ORDER BY name desc ),',',1),
SUBSTRING_INDEX(GROUP_CONCAT(position ORDER BY name desc ),',',1),
SUBSTRING_INDEX(GROUP_CONCAT(location ORDER BY name desc ),',',1),
GROUP_CONCAT(datasources ORDER BY name desc )
from employee_information GROUP BY number

 

 

使用SUBSTRING_INDEX()函數
substring_index(str,delim,count)

str:要處理的字符串

delim:分隔符

count:分隔符計數 

例子
取出上述表中數組的第一個元素

-- SUBSTRING_INDEX(str,'"',2)取出從左往右第二個引號左邊的字符串str
-- SUBSTRING_INDEX(str1,'"',-1)取出從右往左數第一個引號右邊的字符串str_1