Parameters collection (DAO)

Applies to: Access 2013, Office 2013

A Parameters collection contains all the Parameter objects of a QueryDef object.

Remarks

The Parameters collection provides information only about existing parameters. You can't append objects to or delete objects from the Parameters collection.

Example

This example demonstrates Parameter objects and the Parameters collection by creating a temporary QueryDef and retrieving data based on changes made to the QueryDef object's Parameters. The ParametersChange procedure is required for this procedure to run.

    Sub ParameterX() 
     
       Dim dbsNorthwind As Database 
       Dim qdfReport As QueryDef 
       Dim prmBegin As Parameter 
       Dim prmEnd As Parameter 
     
       Set dbsNorthwind = OpenDatabase("Northwind.mdb") 
     
       ' Create temporary QueryDef object with two  
       ' parameters. 
       Set qdfReport = dbsNorthwind.CreateQueryDef("", _ 
          "PARAMETERS dteBegin DateTime, dteEnd DateTime; " & _ 
          "SELECT EmployeeID, COUNT(OrderID) AS NumOrders " & _ 
          "FROM Orders WHERE ShippedDate BETWEEN " & _ 
          "[dteBegin] AND [dteEnd] GROUP BY EmployeeID " & _ 
          "ORDER BY EmployeeID") 
       Set prmBegin = qdfReport.Parameters!dteBegin 
       Set prmEnd = qdfReport.Parameters!dteEnd 
     
       ' Print report using specified parameter values. 
       ParametersChange qdfReport, prmBegin, #1/1/95#, _ 
          prmEnd, #6/30/95# 
       ParametersChange qdfReport, prmBegin, #7/1/95#, _ 
          prmEnd, #12/31/95# 
     
       dbsNorthwind.Close 
     
    End Sub 
     
    Sub ParametersChange(qdfTemp As QueryDef, _ 
       prmFirst As Parameter, dteFirst As Date, _ 
       prmLast As Parameter, dteLast As Date) 
       ' Report function for ParameterX. 
     
       Dim rstTemp As Recordset 
       Dim fldLoop As Field 
     
       ' Set parameter values and open recordset from  
       ' temporary QueryDef object. 
       prmFirst = dteFirst 
       prmLast = dteLast 
       Set rstTemp = _  
          qdfTemp.OpenRecordset(dbOpenForwardOnly) 
       Debug.Print "Period " & dteFirst & " to " & dteLast 
     
       ' Enumerate recordset. 
       Do While Not rstTemp.EOF 
     
          ' Enumerate Fields collection of recordset. 
          For Each fldLoop In rstTemp.Fields 
             Debug.Print " - " & fldLoop.Name & " = " & fldLoop; 
          Next fldLoop 
     
          Debug.Print 
          rstTemp.MoveNext 
       Loop 
     
       rstTemp.Close 
     
    End Sub 

The following example shows how to create a parameter query. A query named myQuery is created with two parameters, named Param1 and Param2. To do this, the SQL property of the query is set to a Structured Query Language (SQL) statement that defines the parameters.

Sample code provided by the Microsoft Access 2010 Programmer’s Reference.

    Sub CreateQueryWithParameters()
    
        Dim dbs As DAO.Database
        Dim qdf As DAO.QueryDef
        Dim strSQL As String
    
        Set dbs = CurrentDb
        Set qdf = dbs.CreateQueryDef("myQuery")
        Application.RefreshDatabaseWindow
    
        strSQL = "PARAMETERS Param1 TEXT, Param2 INT; "
        strSQL = strSQL & "SELECT * FROM [Table1] "
        strSQL = strSQL & "WHERE [Field1] = [Param1] AND [Field2] = [Param2];"
        qdf.SQL = strSQL
    
        qdf.Close
        Set qdf = Nothing
        Set dbs = Nothing
    
    End Sub

The following example shows how to execute a parameter query. The Parameters collection is used to set the Organization parameter of the myActionQuery query before the query is executed.

    Public Sub ExecParameterQuery()
    
        Dim dbs As DAO.Database
        Dim qdf As DAO.QueryDef
    
        Set dbs = CurrentDb
        Set qdf = dbs.QueryDefs("myActionQuery")
    
        'Set the value of the QueryDef's parameter
        qdf.Parameters("Organization").Value = "Microsoft"
    
        'Execute the query
        qdf.Execute dbFailOnError
    
        'Clean up
        qdf.Close
        Set qdf = Nothing
        Set dbs = Nothing
    
    End Sub

The following example shows how to open a Recordset that is based on a parameter query.

    Dim dbs As DAO.Database
    Dim qdf As DAO.QueryDef
    Dim rst As DAO.Recordset
    
    Set dbs = CurrentDb
    
    'Get the parameter query
    Set qfd = dbs.QueryDefs("qryMyParameterQuery")
    
    'Supply the parameter value
    qdf.Parameters("EnterStartDate") = Date
    qdf.Parameters("EnterEndDate") = Date + 7
    
    'Open a Recordset based on the parameter query
    Set rst = qdf.OpenRecordset()