【左连接】坑点

SELECT
  a.*,
   count(c.warehouse_id) stockNum
from
  warehouse111 a
  LEFT JOIN user b ON a.admin_id=b.user_id
  LEFT JOIN stock c ON a.id=c.warehouse_id
  where a.enable_flag=0 and c.enable_flag=0 
group by
  a.id

上面的SQL有问题，左连接变成和内连接一样了，必须跟下面的一样

SELECT
  a.*,
   count(c.warehouse_id) stockNum
from
  warehouse111 a
  LEFT JOIN user b ON a.admin_id=b.user_id
  LEFT JOIN stock c ON a.id=c.warehouse_id and c.enable_flag=0 
  where a.enable_flag=0
group by
  a.id