LEFT JOIN主子表关联查询方法记录

公司前辈让我写一个主子表关联的查询，我完全没有这样的经验，他帮我写了mapper.xml里面的sql语句，记录一下防止以后忘记。

        SELECT *
        FROM
        t_order_wt tr
        
            
                LEFT JOIN t_order_wt_item trw on (tr.company_id = trw.company_id AND tr.order_no = trw.order_no)
                LEFT JOIN t_plan_item tpi on (tpi.parent_company_id = trw.company_id AND tpi.order_no = trw.order_no)
                LEFT JOIN t_plan tp on (tp.company_id = tpi.company_id AND tp.plan_no = tpi.plan_no)
                WHERE tr.company_id = #{companyId}
                AND tp.plan_status >='DDZT55'
                AND tp.plan_status < 'DDZT80'
            
            
                LEFT JOIN t_order_wt_item trw on (tr.company_id = trw.company_id AND tr.order_no = trw.order_no)
                WHERE tr.pick_no = #{pickNo}
            
        
    

和标签组合用来判断具体该执行哪些sql语句