Two tables left link grouping sum query sql statement

select * from  
 
(select member_id,member_name from tb_member  where store_id =1)  a
 
left join
 
(SELECT buyer_id,count(*) order_num,sum(order_amount) order_amount FROM tb_orders wher store_id = 1 GROUP BY buyer_id) b 

on a.member_id=b.buyer_id

Left link queries can link the query result set from a sql statement, the result of a combination of different sets of sql statement can be together.