There are many ways to use parameters in queries. I will try to provide examples for most of them, and where they are applicable.

First, we'll discuss the solutions unique to Access, such as forms, reports and domain aggregates. Then, we'll talk about DAO and ADO.

Using values from forms and reports as parameters

In Access, you can directly use the current value of controls on forms and reports in your SQL code. This limits the need for parameters.

You can refer to controls in the following way:

Forms!MyForm!MyTextbox for a simple control on a form

Forms!MyForm!MySubform.Form!MyTextbox for a control on a subform

Reports!MyReport!MyTextbox for a control on a report

Sample implementation:

DoCmd.RunSQL "INSERT INTO Table1(Field1) SELECT Forms!MyForm!MyTextbox" 'Inserts a single valueDoCmd.RunSQL "INSERT INTO Table1(Field1) SELECT Field1 FROM Table2 WHERE ID = Forms!MyForm!MyTextbox" 'Inserts from a different table

This is available for the following uses:

When using DoCmd.RunSQL, normal queries (in the GUI), form and report record sources, form and report filters, domain aggregates, DoCmd.OpenForm and DoCmd.OpenReport

This is not available for the following uses:

When executing queries using DAO or ADODB (e.g. opening recordsets, CurrentDb.Execute)

Using TempVars as parameters

TempVars in Access are globally available variables, that can be set in VBA or using macro's. They can be reused for multiple queries.

Sample implementation:

TempVars!MyTempVar = Me.MyTextbox.Value 'Note: .Value is requiredDoCmd.RunSQL "INSERT INTO Table1(Field1) SELECT Field1 FROM Table2 WHERE ID = TempVars!MyTempVar"TempVars.Remove "MyTempVar" 'Unset TempVar when you're done using it

Availability for TempVars is identical to that of values from forms and reports: not available for ADO and DAO, available for other uses.

I recommend TempVars for using parameters when opening forms or reports over referring to control names, since if the object opening it closes, the TempVars stay available. I recommend using unique TempVar names for every form or report, to avoid weirdness when refreshing forms or reports.

Using custom functions (UDFs) as parameters

Much like TempVars, you can use a custom function and static variables to store and retrieve values.

Sample implementation:

Option Compare DatabaseOption ExplicitPrivate ThisDate As DatePublic Function GetThisDate() As Date    If ThisDate = #12:00:00 AM# Then        ' Set default value.        ThisDate = Date    End If     GetThisDate = ThisDateEnd FunctionPublic Function SetThisDate(ByVal NewDate As Date) As Date    ThisDate = NewDate    SetThisDate = ThisDateEnd Function

and then:

SetThisDate SomeDateValue ' Will store SomeDateValue in ThisDate.DoCmd.RunSQL "INSERT INTO Table1(Field1) SELECT Field1 FROM Table2 WHERE [SomeDateField] = GetThisDate()"

Also, a single function with an optional parameter may be created for both setting and getting the value of a private static variable:

Public Function ThisValue(Optional ByVal Value As Variant) As Variant    Static CurrentValue As Variant    ' Define default return value.    Const DefaultValue  As Variant = Null    If Not IsMissing(Value) Then        ' Set value.        CurrentValue = Value    ElseIf IsEmpty(CurrentValue) Then        ' Set default value        CurrentValue = DefaultValue    End If    ' Return value.    ThisValue = CurrentValueEnd Function

To set a value:

ThisValue "Some text value"

To get the value:

CurrentValue = ThisValue

In a query:

ThisValue "SomeText"  ' Set value to filter on.DoCmd.RunSQL "INSERT INTO Table1(Field1) SELECT Field1 FROM Table2 WHERE [SomeField] = ThisValue()"

Using DoCmd.SetParameter

The uses of DoCmd.SetParameter are rather limited, so I'll be brief. It allows you to set a parameter for use in DoCmd.OpenForm, DoCmd.OpenReport and some other DoCmd statements, but it doesn't work with DoCmd.RunSQL, filters, DAO and ADO.

Sample implementation

DoCmd.SetParameter "MyParameter", Me.MyTextboxDoCmd.OpenForm "MyForm",,, "ID = MyParameter"

Using DAO

In DAO, we can use the DAO.QueryDef object to create a query, set parameters, and then either open up a recordset or execute the query. You first set the queries' SQL, then use the QueryDef.Parameters collection to set the parameters.

In my example, I'm going to use implicit parameter types. If you want to make them explicit, add a PARAMETERS declaration to your query.

Sample implementation

'Execute query, unnamed parametersWith CurrentDb.CreateQueryDef("", "INSERT INTO Table1(Field1) SELECT Field1 FROM Table2 WHERE Field1 = ?p1 And Field2 = ?p2")    .Parameters(0) = Me.Field1    .Parameters(1) = Me.Field2    .ExecuteEnd With'Open recordset, named parametersDim rs As DAO.RecordsetWith CurrentDb.CreateQueryDef("", "SELECT Field1 FROM Table2 WHERE Field1 = FirstParameter And Field2 = SecondParameter")    .Parameters!FirstParameter = Me.Field1 'Bang notation    .Parameters("SecondParameter").Value = Me.Field2 'More explicit notation    Set rs = .OpenRecordsetEnd With

While this is only available in DAO, you can set many things to DAO recordsets to make them use parameters, such as form recordsets, list box recordsets and combo box recordsets. However, since Access uses the text, and not the recordset, when sorting and filtering, those things may prove problematic if you do.

Using ADO

You can use parameters in ADO by using the ADODB.Command object. Use Command.CreateParameter to create parameters, and then append them to the Command.Parameters collection.

You can use the .Parameters collection in ADO to explicitly declare parameters, or pass a parameter array to the Command.Execute method to implicitly pass parameters.

ADO does not support named parameters. While you can pass a name, it's not processed.

Sample implementation:

'Execute query, unnamed parametersDim cmd As ADODB.CommandSet cmd = New ADODB.CommandWith cmd    Set .ActiveConnection = CurrentProject.Connection 'Use a connection to the current database    .CommandText = "INSERT INTO Table1(Field1) SELECT Field1 FROM Table2 WHERE Field1 = ? And Field2 = ?"    .Parameters.Append .CreateParameter(, adVarWChar, adParamInput, Len(Me.Field1), Me.Field1) 'adVarWChar for text boxes that may contain unicode    .Parameters.Append .CreateParameter(, adInteger, adParamInput, 8, Me.Field2) 'adInteger for whole numbers (long or integer)    .ExecuteEnd With'Open recordset, implicit parametersDim rs As ADODB.RecordsetDim cmd As ADODB.CommandSet cmd = New ADODB.CommandWith cmd    Set .ActiveConnection = CurrentProject.Connection 'Use a connection to the current database    .CommandText = "SELECT Field1 FROM Table2 WHERE Field1 = @FirstParameter And Field2 = @SecondParameter"     Set rs = .Execute(,Array(Me.Field1, Me.Field2))End With

The same limitations as opening DAO recordsets apply. While this way is limited to executing queries and opening recordsets, you can use those recordsets elsewhere in your application.

I have built a fairly basic query builder class to get around the mess of string concatenation and to handle the lack of named parameters. Creating a query is fairly simple.

Public Function GetQuery() As String    With New MSAccessQueryBuilder        .QueryBody = "SELECT * FROM tblEmployees"        .AddPredicate "StartDate > @StartDate OR StatusChangeDate > @StartDate"        .AddPredicate "StatusIndicator IN (@Active, @LeaveOfAbsence) OR Grade > @Grade"        .AddPredicate "Salary > @SalaryThreshhold"        .AddPredicate "Retired = @IsRetired"        .AddStringParameter "Active", "A"        .AddLongParameter "Grade", 10        .AddBooleanParameter "IsRetired", False        .AddStringParameter "LeaveOfAbsence", "L"        .AddCurrencyParameter "SalaryThreshhold", 9999.99@        .AddDateParameter "StartDate", #3/29/2018#        .QueryFooter = "ORDER BY ID ASC"        GetQuery = .ToString    End WithEnd Function

The output of the ToString() method looks like:

SELECT * FROM tblEmployees WHERE 1 = 1 AND (StartDate > #3/29/2018# OR StatusChangeDate > #3/29/2018#) AND (StatusIndicator IN ('A', 'L') OR Grade > 10) AND (Salary > 9999.99) AND (Retired = False) ORDER BY ID ASC;

Each predicate is wrapped in parens to handle linked AND/OR clauses, and parameters with the same name only have to be declared once. Full code is at my github and reproduced below. I also have a version for Oracle passthrough queries that uses ADODB parameters. Eventually, I'd like to wrap both in an IQueryBuilder interface.

VERSION 1.0 CLASSBEGIN  MultiUse = -1  'TrueENDAttribute VB_Name = "MSAccessQueryBuilder"Attribute VB_GlobalNameSpace = FalseAttribute VB_Creatable = TrueAttribute VB_PredeclaredId = FalseAttribute VB_Exposed = True'@Folder("VBALibrary.Data")'@Description("Provides tools to construct Microsoft Access SQL statements containing predicates and parameters.")Option ExplicitPrivate Const mlngErrorNumber As Long = vbObjectError + 513Private Const mstrClassName As String = "MSAccessQueryBuilder"Private Const mstrParameterExistsErrorMessage As String = "A parameter with this name has already been added to the Parameters dictionary."Private Type TSqlBuilder    QueryBody As String    QueryFooter As StringEnd TypePrivate mobjParameters As ObjectPrivate mobjPredicates As CollectionPrivate this As TSqlBuilder' =============================================================================' CONSTRUCTOR / DESTRUCTOR' =============================================================================Private Sub Class_Initialize()    Set mobjParameters = CreateObject("Scripting.Dictionary")    Set mobjPredicates = New CollectionEnd Sub' =============================================================================' PROPERTIES' ============================================================================='@Description("Gets or sets the query statement (SELECT, INSERT, UPDATE, DELETE), exclusive of any predicates.")Public Property Get QueryBody() As String    QueryBody = this.QueryBodyEnd PropertyPublic Property Let QueryBody(ByVal Value As String)    this.QueryBody = ValueEnd Property'@Description("Gets or sets post-predicate query statements (e.g., GROUP BY, ORDER BY).")Public Property Get QueryFooter() As String    QueryFooter = this.QueryFooterEnd PropertyPublic Property Let QueryFooter(ByVal Value As String)    this.QueryFooter = ValueEnd Property' =============================================================================' PUBLIC METHODS' ============================================================================='@Description("Maps a boolean parameter and its value to the query builder.")'@Param("strName: The parameter's name.")'@Param("blnValue: The parameter's value.")Public Sub AddBooleanParameter(ByVal strName As String, ByVal blnValue As Boolean)    If mobjParameters.Exists(strName) Then        Err.Raise mlngErrorNumber, mstrClassName & ".AddBooleanParameter", mstrParameterExistsErrorMessage    Else        mobjParameters.Add strName, CStr(blnValue)    End IfEnd Sub' ============================================================================='@Description("Maps a currency parameter and its value to the query builder.")'@Param("strName: The parameter's name.")'@Param("curValue: The parameter's value.")Public Sub AddCurrencyParameter(ByVal strName As String, ByVal curValue As Currency)    If mobjParameters.Exists(strName) Then        Err.Raise mlngErrorNumber, mstrClassName & ".AddCurrencyParameter", mstrParameterExistsErrorMessage    Else        mobjParameters.Add strName, CStr(curValue)    End IfEnd Sub' ============================================================================='@Description("Maps a date parameter and its value to the query builder.")'@Param("strName: The parameter's name.")'@Param("dtmValue: The parameter's value.")Public Sub AddDateParameter(ByVal strName As String, ByVal dtmValue As Date)    If mobjParameters.Exists(strName) Then        Err.Raise mlngErrorNumber, mstrClassName & ".AddDateParameter", mstrParameterExistsErrorMessage    Else        mobjParameters.Add strName, "#" & CStr(dtmValue) & "#"    End IfEnd Sub' ============================================================================='@Description("Maps a long parameter and its value to the query builder.")'@Param("strName: The parameter's name.")'@Param("lngValue: The parameter's value.")Public Sub AddLongParameter(ByVal strName As String, ByVal lngValue As Long)    If mobjParameters.Exists(strName) Then        Err.Raise mlngErrorNumber, mstrClassName & ".AddNumericParameter", mstrParameterExistsErrorMessage    Else        mobjParameters.Add strName, CStr(lngValue)    End IfEnd Sub' ============================================================================='@Description("Adds a predicate to the query's WHERE criteria.")'@Param("strPredicate: The predicate text to be added.")Public Sub AddPredicate(ByVal strPredicate As String)    mobjPredicates.Add "(" & strPredicate & ")"End Sub' ============================================================================='@Description("Maps a string parameter and its value to the query builder.")'@Param("strName: The parameter's name.")'@Param("strValue: The parameter's value.")Public Sub AddStringParameter(ByVal strName As String, ByVal strValue As String)    If mobjParameters.Exists(strName) Then        Err.Raise mlngErrorNumber, mstrClassName & ".AddStringParameter", mstrParameterExistsErrorMessage    Else        mobjParameters.Add strName, "'" & strValue & "'"    End IfEnd Sub' ============================================================================='@Description("Parses the query, its predicates, and any parameter values, and outputs an SQL statement.")'@Returns("A string containing the parsed query.")Public Function ToString() As StringDim strPredicatesWithValues As String    Const strErrorSource As String = "QueryBuilder.ToString"    If this.QueryBody = vbNullString Then        Err.Raise mlngErrorNumber, strErrorSource, "No query body is currently defined. Unable to build valid SQL."    End If    ToString = this.QueryBody    strPredicatesWithValues = ReplaceParametersWithValues(GetPredicatesText)    EnsureParametersHaveValues strPredicatesWithValues    If Not strPredicatesWithValues = vbNullString Then        ToString = ToString & " " & strPredicatesWithValues    End If    If Not this.QueryFooter = vbNullString Then        ToString = ToString & " " & this.QueryFooter & ";"    End IfEnd Function' =============================================================================' PRIVATE METHODS' ============================================================================='@Description("Ensures that all parameters defined in the query have been provided a value.")'@Param("strQueryText: The query text to verify.")Private Sub EnsureParametersHaveValues(ByVal strQueryText As String)Dim strUnmatchedParameter As StringDim lngMatchedPoisition As LongDim lngWordEndPosition As Long    Const strProcedureName As String = "EnsureParametersHaveValues"    lngMatchedPoisition = InStr(1, strQueryText, "@", vbTextCompare)    If lngMatchedPoisition <> 0 Then        lngWordEndPosition = InStr(lngMatchedPoisition, strQueryText, Space$(1), vbTextCompare)        strUnmatchedParameter = Mid$(strQueryText, lngMatchedPoisition, lngWordEndPosition - lngMatchedPoisition)    End If    If Not strUnmatchedParameter = vbNullString Then        Err.Raise mlngErrorNumber, mstrClassName & "." & strProcedureName, "Parameter " & strUnmatchedParameter & " has not been provided a value."    End IfEnd Sub' ============================================================================='@Description("Combines each predicate in the predicates collection into a single string statement.")'@Returns("A string containing the text of all predicates added to the query builder.")Private Function GetPredicatesText() As StringDim strPredicates As StringDim vntPredicate As Variant    If mobjPredicates.Count > 0 Then        strPredicates = "WHERE 1 = 1"        For Each vntPredicate In mobjPredicates            strPredicates = strPredicates & " AND " & CStr(vntPredicate)        Next vntPredicate    End If    GetPredicatesText = strPredicatesEnd Function' ============================================================================='@Description("Replaces parameters in the predicates statements with their provided values.")'@Param("strPredicates: The text of the query's predicates.")'@Returns("A string containing the predicates text with its parameters replaces by their provided values.")Private Function ReplaceParametersWithValues(ByVal strPredicates As String) As StringDim vntKey As VariantDim strParameterName As StringDim strParameterValue As StringDim strPredicatesWithValues As String    Const strProcedureName As String = "ReplaceParametersWithValues"    strPredicatesWithValues = strPredicates    For Each vntKey In mobjParameters.Keys        strParameterName = CStr(vntKey)        strParameterValue = CStr(mobjParameters(vntKey))        If InStr(1, strPredicatesWithValues, "@" & strParameterName, vbTextCompare) = 0 Then            Err.Raise mlngErrorNumber, mstrClassName & "." & strProcedureName, "Parameter " & strParameterName & " was not found in the query."        Else            strPredicatesWithValues = Replace(strPredicatesWithValues, "@" & strParameterName, strParameterValue, 1, -1, vbTextCompare)        End If    Next vntKey    ReplaceParametersWithValues = strPredicatesWithValuesEnd Function' =============================================================================