Question

我正在尝试更正此查询，我需要首先加入表格capcase，然后加入名为capstatus second的表格。从capcase状态和capcaseservicesprovidedstatus有不同的表格，其中可以看到外键，我需要加入正确的表。我想知道是否可能需要使用除“内连接”之外的连接来完成此任务或确认我的查询错误，因为最后两行是我认为存在的问题。如有任何帮助，请提前感谢。

SELECT family.Id as Family_ID,  person.firstName + ' ' + person.lastName as Name, capcaseServicesProvided.idperson as Person_ID,capcaseservicesProvided.idCase as Case_ID, capcaseServicesProvided.Id as Service_ID,capStatus.Status as Case_Status, capServices.Service, capStatusService.ServiceStatus as Service_Status, 
capcaseServicesProvided.Qty, capServicesUnit.Unit, capcaseServicesProvided.Date as Service_Date, capCase.DateApplied as Case_Date

FROM capcaseServicesProvided

INNER JOIN person on capcaseServicesProvided.idperson = person.Id
INNER JOIN capServices on capcaseServicesProvided.idService = capServices.Id
INNER JOIN capServicesUnit on capcaseServicesProvided.Unit = capServicesUnit.Id
INNER JOIN capStatusService on capcaseServicesProvided.Status = capStatusService.Id
INNER JOIN family on person.idFamily = family.Id
INNER JOIN capStatus on capcaseServicesProvided.Status= capStatus.Id
INNER JOIN capCase on capCaseServicesProvided.Date = capCase.DateApplied;

Answer 1

我想建议一种方法，而不是尝试一种特定的解决方案。请注意，我们对您的表格或其设计一无所知，因此要求我们理解要么需要相当多的信息，所以最终您最好了解JOINS和/或如何自己解决这些困境。

我建议你将初始查询的大小减少到ABSOLUTE MINIMUM，看起来（我认为）是这样的：

SELECT
        family.Id AS Family_ID
      , person.firstName + ' ' + person.lastName AS Name
      , capcaseServicesProvided.idperson AS Person_ID
      , capcaseservicesProvided.idCase AS Case_ID
      , capcaseServicesProvided.Id AS Service_ID
FROM capcaseServicesProvided
INNER JOIN person ON capcaseServicesProvided.idperson = person.Id
INNER JOIN family ON person.idFamily = family.Id
;

现在假设最小查询是正确的，尝试加入ONE EXTRA TABLE并将其中所需的列包含在select子句中。首先使用INNER JOIN添加额外的表。如果您注意到某些行要消失，则将其更改为LEFT JOIN

e.g。

SELECT
        family.Id AS Family_ID
      , person.firstName + ' ' + person.lastName AS Name
      , capcaseServicesProvided.idperson AS Person_ID
      , capcaseservicesProvided.idCase AS Case_ID
      , capcaseServicesProvided.Id AS Service_ID
      , capServices.Service
FROM capcaseServicesProvided
INNER JOIN person ON capcaseServicesProvided.idperson = person.Id
INNER JOIN family ON person.idFamily = family.Id
INNER JOIN capServices ON capcaseServicesProvided.idService = capServices.Id
-- or if needed --LEFT JOIN capServices ON capcaseServicesProvided.idService = capServices.Id
;

继续重复此循环，直到您加入所有需要的表格。

我怀疑你只需要一个或多个LEFT JOINS但没有来自每个表的样本数据和每个表的DDL，很难告诉你哪些表需要这些。

SQL内部联接问题/替代加入

1 个答案: