如ss是varchar类型的话
sql Server:
like '%'+@ss+'%' (SQL Server中所有用户定义的变量都以“@”开头)
oracle:
like '%'||ss||'%'
declare
@ss varchar(20);
begin
set @ss='tom';
select * from student where name like '%'+@ss'%';
end;
select * from student where name like '%'||ss||'%';