Trying to use variables as values vba to sql

Question

Dim connection As New adodb.connection        
Dim sql As String
Dim years As Integer
years = 2011

So I've got some nice declared variables here. Now I'm going to show the statement that works perfectly, no problems:

sql = "insert into crimeData(reportYear) values(2011)"
connection.Execute sql

Notice I hardcoded in the year. Now, if I try:

sql = "insert into crimeData(reportYear) values(years)"
connection.Execute sql

Substituting the variable name in as a value, I get the error: No value given for one or more required parameters

Admittedly, I'm assuming there's got to be a simple syntax issue, or some meta with variables I'm missing. Please enlighten me. How can I correctly swap in a variable here (so I can use this programatically, as opposed to hard coding in values)

Answer 1

If you have a more demanding need for concatenating SQL, you may benefit from this function:

' Converts a value of any type to its string representation.
' The function can be concatenated into an SQL expression as is
' without any delimiters or leading/trailing white-space.
'
' Examples:
'   SQL = "Select * From TableTest Where [Amount]>" & CSql(12.5) & "And [DueDate]<" & CSql(Date) & ""
'   SQL -> Select * From TableTest Where [Amount]> 12.5 And [DueDate]< #2016/01/30 00:00:00#
'
'   SQL = "Insert Into TableTest ( [Street] ) Values (" & CSql(" ") & ")"
'   SQL -> Insert Into TableTest ( [Street] ) Values ( Null )
'
' Trims text variables for leading/trailing Space and secures single quotes.
' Replaces zero length strings with Null.
' Formats date/time variables as safe string expressions.
' Uses Str to format decimal values to string expressions.
' Returns Null for values that cannot be expressed with a string expression.
'
' 2016-01-30. Gustav Brock, Cactus Data ApS, CPH.
' 2019-12-31. Modified to compile in both 32- and 64-bit VBA.
'
Public Function CSql( _
    ByVal Value As Variant) _
    As String

    #If Win32 Then
        ' Serves only to make the code compile unmodified in 32-bit VBA
        ' which misses the constant VBA.vbLongLong.
        Const vbLongLong    As Integer = 20
    #End If

    Const SqlNull           As String = " Null"

    Dim Sql                 As String

    Select Case VarType(Value)
        Case vbEmpty            '    0  Empty (uninitialized).
            Sql = SqlNull
        Case vbNull             '    1  Null (no valid data).
            Sql = SqlNull
        Case vbInteger          '    2  Integer.
            Sql = Str(Value)
        Case vbLong             '    3  Long integer.
            Sql = Str(Value)
        Case vbSingle           '    4  Single-precision floating-point number.
            Sql = Str(Value)
        Case vbDouble           '    5  Double-precision floating-point number.
            Sql = Str(Value)
        Case vbCurrency         '    6  Currency.
            Sql = Str(Value)
        Case vbDate             '    7  Date.
            Sql = Format(Value, " \#yyyy\/mm\/dd hh\:nn\:ss\#")
        Case vbString           '    8  String.
            Sql = Replace(Trim(Value), "'", "''")
            If Sql = "" Then
                Sql = SqlNull
            Else
                Sql = " '" & Sql & "'"
            End If
        Case vbObject           '    9  Object.
            Sql = SqlNull
        Case vbError            '   10  Error.
            Sql = SqlNull
        Case vbBoolean          '   11  Boolean.
            Sql = Str(Abs(Value))
        Case vbVariant          '   12  Variant (used only with arrays of variants).
            Sql = SqlNull
        Case vbDataObject       '   13  A data access object.
            Sql = SqlNull
        Case vbDecimal          '   14  Decimal.
            Sql = Str(Value)
        Case vbByte             '   17  Byte.
            Sql = Str(Value)
        Case vbLongLong         '   20  LongLong integer (Relevant in 64-bit VBA only).
            Sql = Str(Value)
        Case vbUserDefinedType  '   36  Variants that contain user-defined types.
            Sql = SqlNull
        Case vbArray            ' 8192  Array. Ignored.
            Sql = SqlNull
        Case Else               '       Should not happen.
            Sql = SqlNull
    End Select

    CSql = Sql & " "

End Function