BuildCriteria Method

The BuildCriteria method returns a parsed criteria string as it would appear in the query design grid, in Filter By Form or Server Filter By Form mode. For example, you may want to set a form's Filter or ServerFilter property based on varying criteria from the user. You can use the BuildCriteria method to construct the string expression argument for the Filter or ServerFilter property. String.

expression   Required. An expression that returns one of the objects in the Applies To list.

Field  Required String. A string expression identifying the field for which you wish to define criteria.

FieldType  Required Integer. An intrinsic constant denoting the data type of the field. For a list of possible field data types, see the ADO Type property.

Expression  Required String. A string expression identifying the criteria to be parsed.

Remarks

The BuildCriteria method returns a string.

The BuildCriteria method enables you to easily construct criteria for a filter based on user input. It parses the expression argument in the same way that the expression would be parsed had it been entered in the query design grid, in Filter By Form or Server Filter By Form mode.

For example, a user creating a query on an Orders table might restrict the result set to orders placed after January 1, 1995, by setting criteria on an OrderDate field. The user might enter an expression such as the following one in the Criteria row beneath the OrderDate field:

>1-1-95

Microsoft Access automatically parses this expression and returns the following expression:

>#1/1/95#

The BuildCriteria method provides the same parsing from Visual Basic code. For example, to return the preceding correctly parsed string, you can supply the following arguments to the BuildCriteria method:

Dim strCriteria As String
strCriteria = BuildCriteria("OrderDate", dbDate, ">1-1-95")

Since you need to supply criteria for the Filter property in correctly parsed form, you can use the BuildCriteria method to construct a correctly parsed string.

You can use the BuildCriteria method to construct a string with multiple criteria if those criteria refer to the same field. For example, you can use the BuildCriteria method with the following arguments to construct a string with multiple criteria relating to the OrderDate field:

strCriteria = BuildCriteria("OrderDate", dbDate, ">1-1-95 and <5-1-95")

This example returns the following criteria string:

OrderDate>#1/1/95# And OrderDate<#5/1/95#

However, if you wish to construct a criteria string that refers to multiple fields, you must create the strings and concatenate them yourself. For example, if you wish to construct criteria for a filter to show records for orders placed after 1-1-95 and for which freight is less than $50, you would need to use the BuildCriteria method twice and concatenate the resulting strings.

Example

The following example prompts the user to enter the first few letters of a product's name and then uses the BuildCriteria method to construct a criteria string based on the user's input. Next, the procedure provides this string as an argument to the Filter property of a Products form. Finally, the FilterOn property is set to apply the filter.

Sub SetFilter()
    Dim frm As Form, strMsg As String
    Dim strInput As String, strFilter As String

    ' Open Products form in Form view.
    DoCmd.OpenForm "Products"
    ' Return Form object variable pointing to Products form.
    Set frm = Forms!Products
    strMsg = "Enter one or more letters of product name " _
        & "followed by an asterisk."
    ' Prompt user for input.
    strInput = InputBox(strMsg)
    ' Build criteria string.
    strFilter = BuildCriteria("ProductName", dbText, strInput)
    ' Set Filter property to apply filter.
    frm.Filter = strFilter
    ' Set FilterOn property; form now shows filtered records.
    frm.FilterOn = True
End Sub