如何使用Delphi应用程序在MS Access数据库中创建VIEW，而无需在PC上安装MSAccess？

Question

我想在MS Access上创建VIEW定义。我已经使用以下CREATE VIEW声明：

SELECT 
    MFP.FollowUpPlan_Id, 
    MFP.FollowUpPlan_Name AS PlanName, 
    DFP.Sequence_No AS SequenceNo, 
    MFS.FollowUpSchedule_Name AS ScheduleName  
FROM 
    MAS_FollowUp_Plan AS MFP, 
    DET_FollowUp_Plan AS DFP, 
    MAS_FollowUp_Schedule AS MFS 
WHERE 
    (((MFP.FollowUpPlan_Id)=DFP.FollowUpPlan_Id) AND 
    ((DFP.FollowUpSchedule_Id)=MFS.FollowUpSchedule_Id)) AND 
    MFP.is_Deleted = FALSE AND 
    DFP.is_Deleted = false  
ORDER BY 
    MFP.FollowUpPlan_Id, DFP.Sequence_No;  

但它抛出一个错误：

Only Simple Select Queries are allowed in view. 

请帮帮忙，先谢谢了。

Answer 1

声明变量olevarCatalog，在Delphi在cmd作为OleVariant，用途ComObj

olevarCatalog := CreateOleObject('ADOX.Catalog'); 
olevarCatalog.create(YourConnectionString); //This Will create MDB file. 
// Using ADO Query(CREATE TABLE TABLEName....) add the required Tables. 

// To Insert View Definition on MDB file. 
cmd := CreateOleObject('ADODB.Command'); 
cmd.CommandType := cmdText; 
cmd.CommandText := 'ANY Kind of SELECT Query(JOIN, OrderBy is also allowed)'; 
olevarCatalog.Views.Append('Name of View',cmd); 
cmd := null; 

这是为了创建MS Access文件（.mdb）和用Delphi景色的最佳方式。

Answer 2

You cannot mix ORDER BY with JOIN when creating views in Access。它会给你错误"Only simple SELECT queries are allowed in VIEWS."（注意复数VIEWS）

在FROM有多个表是JOIN的一种。

• 或者删除ORDER BY，
• 或在FROM和没有JOIN只有一个表。

我记得从过去（当我做了更多的访问的东西比现在）看到这一个大的查询与单个表选择ORDER BY以及。

The consensus is that you should not have ORDER BY in views anyway，所以这是你最好的做法。

Another reason that you can get the same error message是如果您添加参数或子选择。访问不喜欢视图中的那些，但在您看来，情况并非如此。

Answer 3

正如Jeroen解释的，这里的问题是Access'CREATE VIEW声明的限制。对于这种情况，您可以改用CREATE PROCEDURE。它将创建db的QueryDefs集合的新成员---所以从Access用户界面将显示为新的命名查询。

以下语句适用于使用VBScript中的ADO。从以前的德尔福在这里的问题，我的理解是，德尔福也可以使用ADO，所以我相信这也适用于你。

CREATE PROCEDURE ViewSubstitute AS 
SELECT 
    MFP.FollowUpPlan_Id, 
    MFP.FollowUpPlan_Name AS PlanName, 
    DFP.Sequence_No AS SequenceNo, 
    MFS.FollowUpSchedule_Name AS ScheduleName 
FROM 
    (MAS_FollowUp_Plan AS MFP 
    INNER JOIN DET_FollowUp_Plan AS DFP 
    ON MFP.FollowUpPlan_Id = DFP.FollowUpPlan_Id) 
    INNER JOIN MAS_FollowUp_Schedule AS MFS 
    ON DFP.FollowUpSchedule_Id = MFS.FollowUpSchedule_Id 
WHERE 
    MFP.is_Deleted=False AND DFP.is_Deleted=False 
ORDER BY 
    MFP.FollowUpPlan_Id, 
    DFP.Sequence_No;