从Access向SQL Server中的变量传递值

Question

I have a large query in SQL Server that returns many rows and columns. I need to create a user interface in MS Access for that query. In order to run the query I need to pass some variables to the query. For example:

DECLARE @start_date date, @end_date date SELECT * FROM myTable WHERE Date BETWEEN @start_date AND @end_date

I know that I can't have a DECLARE statement in the ACCESS query viewer. But is there another way of passing these parameters to the query? I've read that it can be done with VBA, but I just want to confirm that there is no other way of passing values to the variable.

Ideally, what I will need is to interact with SQL Server via MS ACCESS

Thanks

Answer 1

You don't mention where/how/when that query is saved on SQL server. Stating that you have large query but leaving out where this query resides is big detail.

However, you asking can you pass values to SQL server without any code? The answer is yes, but this means your best approach is to create + save the large query server side as a VIEW. You will NOT need any parameters.

You then when launching the form (or report) in access, simply attached a where clause:

MyDate is Between Forms!ReportPrompt!startDate and forms!ReportPrompt!EndDate

The above means no VBA, no parameters and if the query has 1 million rows but only ONE row matches your criteria then ONLY the one row will come down the network pipe. You can just type the above into the reports Filter and just set the report to filter on load property = Yes.

However as noted you don't supply much information as to where or how your query is saved server side. If you talking about a store procedure (a massive detail to leave out), then you can pass parmaters this way:

Dim qdfPass       As DAO.QueryDef 
Dim rst           As DAO.Recordset 
Set qdfPass = CurrentDb.QueryDefs("MyPass") 
qdfPass.SQL = "exec sp_myProc " &  MyP1Var & "," & MyP2Var
qdfPass.Execute

The above assumes you saved a pass through query client side called MyPass.

In fact there is a dozen ways to pass values to SQL server, but without any more information as to where/how/when/when and under what context that query data is to be consumed then we are faced only with wild and speculative guessing.

If the resulting data is to be used for a report, then as noted you don't really need (nor will benefit) from a store procedure and using a "where" clause as part of the open report command will suffice. The same advice applies if you want this data returned to a form.

If the query and store procedure is only going to do server side processing, then the above code to call a store procedure and pass paramaters will suffice.

Answer 2

@Albert D. Kallal has given the best way of doing this which is to use a stored procedure and pass in the values as parameters. There are a few other ways of doing this for example :-

1. Via ADODB in VBA code :-

   Dim con As New ADODB.Connection Dim rs As New ADODB.Recordset

   con.Open "SQLSrv", "User", "Pass" rs.Open "DECLARE @start_date date, @end_date date; SELECT * FROM myTable WHERE Date BETWEEN @start_date AND @end_date", con

2. You can write a "Pass through" query that does the same thing.

Both these methods will work at the moment however Microsoft are trying to remove the support for passing in multiple SQL statements in a single execute and you may find that later versions of TDS ( Tabular Data Stream - the protocol MS OBDC drivers communicates with SQL Server ) do not support this.

Answer 3

Yes, there are ways to pass parameters to a query via Access. You can use controls on a form (textbox, etc.). You then reference the controls in the Criteria ( WHERE ) portion of your SQL.

So if I wanted to DELETE * records for an employee in a table between two dates that a user specifies, I would reference the control on the form, like this:

Between Forms![StartDateTxt] And Forms![EndDateTxt]