MS Access SQL 多个 JOIN 和 WHERE 子句

Posted 2023-05-07

【中文标题】MS Access SQL 多个 JOIN 和 WHERE 子句

【英文标题】：MS Access SQL multiple JOIN and WHERE clauses

【发布时间】：2014-02-26 18:32:10

【问题描述】：

我正在尝试将多个表连接到一个名为“Claims”的主表（代码如下） 三张表有以下条件

[NYS Medicaid Fee Schedule Jan12] 具有重复键，并且必须选择正确的记录，其中主表中的值介于查找表中的两个日期之间 [NYS Medicaid Fee Schedule Apr13] 具有重复键，并且必须选择正确的记录，其中主表中的值介于查找表中的两个日期之间 [NY Medicare] 有重复的键，必须将“区域”视为第二级才能选择正确的记录

当我只使用一个 WHERE 子句时，查询有效并且没有问题。为单独的表添加 1 个或两个额外的 WHERE 条件会导致麻烦。

我在互联网上进行了大量研究，发现括号对 ACCESS 非常重要。我看到了有关多个连接的正确语法的示例，但没有看到针对特定表的带有 WHERE 子句的多个连接。

我希望我只是误解了如何放置括号。

---

FROM ( ( ( ( ( ( [Claims]  
LEFT JOIN [BillType] ON [Claims].[Bill_Type] = [BillType].[BillType_Bill Type Key] )  
LEFT JOIN [PlaceofService] ON [Claims].[Place_of_Service] = [PlaceofService].[POS_Place of Service] )  
LEFT JOIN [Participating] ON [Claims].[TIN] = [Participating].[TIN] )  
LEFT JOIN [NYS Medicaid Fee Schedule Apr11] ON [Claims].[FivedigitProcCode] = [NYS Medicaid Fee Schedule Apr11].[Apr11_NYS_CODE] )  
LEFT JOIN [NYS Medicaid Fee Schedule Jan12] ON [Claims].[FivedigitProcCode] = [NYS Medicaid Fee Schedule Jan12].[Jan12_NYS_CODE]  
  WHERE [Claims].[BeginningDOS] BETWEEN [NYS Medicaid Fee Schedule Jan12].[Jan12_NYS_EFFECTIVE DATE] AND [NYS Medicaid Fee Schedule Jan12].[Jan12_NYS_END DATE] )  
LEFT JOIN [NYS Medicaid Fee Schedule Apr13] ON [Claims].[FivedigitProcCode] = [NYS Medicaid Fee Schedule Apr13].[Apr13_NYS_CODE]    
  WHERE [Claims].[BeginningDOS] BETWEEN [NYS Medicaid Fee Schedule Apr13].[Apr13_NYS_EFFECTIVE DATE] AND [NYS Medicaid Fee Schedule Apr13].[Apr13_NYS_END DATE] )  
LEFT JOIN [NY Medicare] ON [Claims].[FivedigitProcCode] = [NY Medicare].[MEDICARE_HCPCS CODE]  
  WHERE [Claims].[Zone] = [NY Medicare].[MEDICARE_ZONE]  

【参考方案1】：

一个 SQL 查询只有一个 where 子句。您应该将这些条件更改为 on 条件的一部分：

FROM ( ( ( ( ( ( [Claims]  
LEFT JOIN [BillType] ON [Claims].[Bill_Type] = [BillType].[BillType_Bill Type Key] )  
LEFT JOIN [PlaceofService] ON [Claims].[Place_of_Service] = [PlaceofService].[POS_Place of Service] )  
LEFT JOIN [Participating] ON [Claims].[TIN] = [Participating].[TIN] )  
LEFT JOIN [NYS Medicaid Fee Schedule Apr11] ON [Claims].[FivedigitProcCode] = [NYS Medicaid Fee Schedule Apr11].[Apr11_NYS_CODE] )  
LEFT JOIN [NYS Medicaid Fee Schedule Jan12] ON [Claims].[FivedigitProcCode] = [NYS Medicaid Fee Schedule Jan12].[Jan12_NYS_CODE]  
  AND [Claims].[BeginningDOS] BETWEEN [NYS Medicaid Fee Schedule Jan12].[Jan12_NYS_EFFECTIVE DATE] AND [NYS Medicaid Fee Schedule Jan12].[Jan12_NYS_END DATE] )  
LEFT JOIN [NYS Medicaid Fee Schedule Apr13] ON [Claims].[FivedigitProcCode] = [NYS Medicaid Fee Schedule Apr13].[Apr13_NYS_CODE]    
  AND [Claims].[BeginningDOS] BETWEEN [NYS Medicaid Fee Schedule Apr13].[Apr13_NYS_EFFECTIVE DATE] AND [NYS Medicaid Fee Schedule Apr13].[Apr13_NYS_END DATE] )  
LEFT JOIN [NY Medicare] ON [Claims].[FivedigitProcCode] = [NY Medicare].[MEDICARE_HCPCS CODE]  
  AND [Claims].[Zone] = [NY Medicare].[MEDICARE_ZONE]