试试这个

select no,username,role1 +','+role2+','+role3 as ROLE from UserData

如果您需要将数值数据类型与varchar数据类型组合，那么您需要使用此

in case you need to combine a numeric data type with varchar datatype then you need to use this

select no,username,cast(no as varchar)+','+role1 +','+role2+','+role3 as ROLE from UserData