Question

有谁能告诉我为什么会收到此错误？

SELECT C.ClientID, C.ClientCode, C.FullName, E.FullName AS EmployeeName

FROM ClientID C, EmployeeInfo E, tmntClientTreatmentInfo T, CliniciansClients CC

JOIN CliniciansClients
ON CliniciansClients.ClientID = ClientID.ClientID
JOIN ClientID
ON ClientID.ClientID = CliniciansClients.ClientID
JOIN EmployeeInfo
ON EmployeeInfo.EmployeeID = CliniciansClients.EmployeeID
JOIN tmntClientTreatmentInfo
ON tmntClientTreatmentInfo.ClientID = ClientID.ClientID

多部分标识符＆＃34; ClientID.ClientID＆＃34;无法受约束。 //第6行

Answer 1

Tony，有很多方法可以选择连接和许多不同类型的连接。但我建议你从做一些基本的事情开始，确保它有效，然后如果它不具备性能或带回重复数据，则开始优化连接或处理规范化/非规范化。过了一会儿，你就会掌握它。在那之前，我在Docker中快速设置了一个postgres实例，创建了你引用的表，这个查询应该可以工作：

SELECT C.ClientID, C.ClientCode, C.FullName, E.FullName AS EmployeeName

FROM ClientID C

JOIN CliniciansClients AS CC
ON CC.ClientID = C.ClientID
JOIN EmployeeInfo AS E
ON E.EmployeeID = CC.EmployeeID
JOIN tmntClientTreatmentInfo as leonardo
ON leonardo.ClientID = C.ClientID

SQL - 无法绑定多部分标识符

1 个答案: