SQL语句两种方式实现关联查询

    SELECT p.id,p.name,p.parent_id,p.path,p.level,p.created,p.updated,
   c.id AS c_id,c.name AS c_name,c.parent_id AS c_parent_id,c.path AS c_path,
   c.level AS c_level,c.created AS c_created,c.updated AS c_updated
    FROM
(SELECt * FROM rights WHERe parent_id=0) AS p
   LEFT JOIN
      rights AS c
    ON p.id =c.parent_id

   
   
      
         
      
            
         
         
         
         
         
         
         
      

   


   
   
      select *from rights where  parent_id = 0
   

   
      
      
   

   
      select * from rights where parent_id = #{id}