MySQL查询多对多关系。

本文介绍了MySQL查询多对多关系。的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有三张桌子 user_branch中的分支基本上是位置，据说是A，B，C user_acct_type中的帐户类型是帐户类型可能是D，E，F，G，H

user_branch -------- -------------------------- Sr-no |用户名|分公司| ---------------------------------- 1 |用户1 | A | 2 |用户1 | B | 3 |用户2 | A | 4 |用户2 | C | --------------------------------- | user_acct_type --------------------------------- - Sr-no |用户名| Acct_type | ----------------------------------- 1 |用户1 | D | 2 |用户1 | E | 3 |用户2 | F | 4 |用户2 | G | ----------------------------------- | cust_code --------------------------------- ------------------------------------------ Sr-no |客户名称|客户代码|分公司|帐户类型| ---------------------------------------------- ----------------------------- 1 |客户1 | 1234 | A | D | 2 |客户2 | 1235 | C | F | 3 |客户3 | 1236 | B | G | 4 |客户4 | 1237 | A | H | ---------------------------------------------- ---------------------------- |

基本上我的要求是用户1应该只能搜索那些分支是A或B的客户名称（如表user_branch中所指定的），同时只搜索帐户类型为D或E的客户名称（在user_acct_type中指定。我无法对任何查询进行qrite，以便在单个查询中满足所有条件。任何帮助表示赞赏。谢谢 编辑我尝试了查询

选择 c.Cust_Name as 客户 来自 custcode c 内部 join user_branch b on c.branch = b。分支 内部 加入 user_acctype a c.Cust_typeofaccount = a.acctype order by c.Cust_Name

现在我的问题是如何根据用户会话过滤掉结果？

解决方案

SELECT a .Sr-no`，.Customer Name`，a .Customer Code` FROM `cust_code` a，`user_acct_type` b，`user_branch `c WHERE b。 `Acct_type` = a .Acct_type` AND c .Branch` = a .Branch` AND b .Username` = c .Username` AND c .Username` = ' 用户1'

I have three tables Branch in user_branch is basically locations supposedly A,B,C Account type in user_acct_type is account type may be D,E,F,G,H

user_branch ---------------------------------- Sr-no | Username | Branch | ---------------------------------- 1 | User 1 | A | 2 | User 1 | B | 3 | User 2 | A | 4 | User 2 | C | ---------------------------------| user_acct_type ----------------------------------- Sr-no | Username | Acct_type | ----------------------------------- 1 | User 1 | D | 2 | User 1 | E | 3 | User 2 | F | 4 | User 2 | G | -----------------------------------| cust_code --------------------------------------------------------------------------- Sr-no | Customer Name | Customer Code | Branch | Account Type | --------------------------------------------------------------------------- 1 | Customer 1 | 1234 | A | D | 2 | Customer 2 | 1235 | C | F | 3 | Customer 3 | 1236 | B | G | 4 | Customer 4 | 1237 | A | H | --------------------------------------------------------------------------|

Basically my requirement is that User 1 should be able to search for only those customers names whose branch is A or B(as specified in the table user_branch) and at the same time only those customer names whose account type is D or E(as specified in user_acct_type). I am not able to qrite any query such that all the conditions are satisfied in a single query. Any help is appreciated. Thanks Edit I tried the query

select c.Cust_Name as Customer from custcode c inner join user_branch b on c.branch = b.branch inner join user_acctype a on c.Cust_typeofaccount = a.acctype order by c.Cust_Name

Now my question is how do I filter out the results based on user session?

解决方案

SELECT a.`Sr-no`, a.`Customer Name`, a.`Customer Code` FROM `cust_code` a, `user_acct_type` b, `user_branch` c WHERE b. `Acct_type`=a.`Acct_type ` AND c.`Branch`=a.`Branch` AND b.`Username`=c.`Username` AND c.`Username`='User 1'