SELECT pname
FROM products 
WHERE pname like (@key + '%') 
union all
   SELECT typename
FROM products 
WHERE typename like (@key + '%') 
union all
   SELECT stylename 
FROM products 
WHERE stylename like (@key + '%')

------解决方案--------------------
把SQL语句改一下，另外后台在查询字段前也加个%
SQL code

SELECT pname FROM products WHERE pname like ('%'+@key + '%') union all 
SELECT typename FROM products where typename like ('%'+@key + '%') union all 
SELECT stylename FROM products where stylename like ('%'+@key + '%')

------解决方案--------------------

SQL code

select * from(
SELECT pname as name,clickcount 
FROM products 
WHERE pname like (@key + '%') 
union 
SELECT typename,clickcount 
FROM products 
WHERE typename like (@key + '%') 
union 
SELECT stylename,clickcount  
FROM products 
WHERE stylename like (@key + '%')
) t order by name,clickcount