加入查看表格转换答案

【问题标题】：join to view table convert加入查看表格转换
【发布时间】：2019-06-07 13:31:02
【问题描述】：

我想将左连接转换为view table。

Following is my SQL

 SELECT d.account_no, COALESCE(d.deposits, 0) - COALESCE(w.withdrawals, 0) 
   AS balance
  FROM (SELECT account_no, SUM(deposit_amount) AS deposits
   FROM deposits
  GROUP BY account_no) d
  LEFT JOIN (SELECT account_no, SUM(withdraw_amount) AS withdrawals
       FROM withdraws
       GROUP BY account_no) w ON w.account_no = d.account_no

我想创建view 表。

我怎样才能做到这一点？有人可以帮忙吗？

【问题讨论】：

您是在问如何创建视图吗？ dev.mysql.com/doc/refman/8.0/en/create-view.html
合并两张表然后有条件地汇总存款和取款可能会更好。
我想隐蔽left join查看表格
视图语法很简单你有什么问题？（您不能将视图创建为 select 语句的一部分）
如何创建视图表。我想要同样的结果

标签： php mysql sql laravel-5 mysqli

【解决方案1】：

创建视图（一次）并在左连接中使用

CREATE  VIEW my_view AS 
SELECT account_no, SUM(withdraw_amount) AS withdrawals
       FROM withdraws
       GROUP BY account_no
;


SELECT d.account_no, COALESCE(d.deposits, 0) - COALESCE(w.withdrawals, 0) 
 AS balance
FROM (SELECT account_no, SUM(deposit_amount) AS deposits
 FROM deposits
GROUP BY account_no) d
LEFT JOIN my_view  w ON w.account_no = d.account_no

【讨论】：

第一个错误：CREATE my_view VIEW AS SELECT account_no, SUM(withdraw_amount) AS 取款 FROM 取款 GROUP BY account_no
第二个错误：#1064 - 您的 SQL 语法有错误；检查与您的 MariaDB 服务器版本相对应的手册，以在第 1 行的“my_view VIEW AS SELECT account_no, SUM(withdraw_amount) AS 提款”附近使用正确的语法