一对多关联多表查询：如何拆分显示收发方客户姓名列

要分别展示发件人和收件人的姓名，你需要两次关联client表，给每次关联的表设置不同别名，对应不同的连接条件即可：

SELECT 
    sender_client.Name_client AS sender_name,
    recipient_client.Name_client AS recipient_name,
    -- 可按需添加shipment、employee的其他字段
    shipment.*,
    employee.*
FROM package
JOIN shipment ON package.Shipment_ = shipment.ShipmentID
JOIN client AS sender_client ON sender_client.AccountNumber = package.sender
JOIN client AS recipient_client ON recipient_client.AccountNumber = package.recipient
JOIN employee ON employee.employeeID = shipment.manager;

关键说明： #

• 原查询用OR关联client表会导致单条package数据生成两条重复结果，且无法区分收发方姓名列；两次独立关联能在同一行同时展示双方信息
• 通过别名sender_client和recipient_client区分两次关联的client表，分别匹配package的sender和recipient字段

内容的提问来源于stack exchange，提问作者Vegeta_sama