我有下表朋友
id | first_name | last_name | gender | age | mobile
1 | bobby | roe | male | 21 | 541-5780
如何将多列(first_name和last_name)值连接到一个列中以获得以下结果？
full_name
bobby roe
我写了以下查询,但它不起作用
declare @full_name varchar(max)
select @full_name = COALESCE(@full_name + ', ', '') + first_name, last_name
from friend
select @full_name