dynamic select statement where the parameter count determines the or condition - sql

Question

I have a listbox with multiselect that provides multiple values.I need a select statement from the below
select Amount from tblEmployeeTransactions _
where PayrollCode_Code = '" & code & "' "
my listboxdata is obtained as below
For Each drv As CListItem In lstnoncash.SelectedItems
code =drv.ItemData
Next
my desired query should be
select sum(Amount) from tblEmployeeTransactions _
where PayrollCode_Code = '1' or PayrollCode_Code ='2' or PayrollCode_Code ='3'"
If it has 3 rows of data

Answer 1

You may want something like this :
Dim a As String() = {"1", "2", "3"}
Dim query = "select sum(Amount) from tblEmployeeTransactions " _
& "where PayrollCode_Code IN "
'here inStatement will contain : ('1', '2', '3')'
Dim inStatement = "('" & String.Join("', '", a) & "')"
Console.WriteLine(query & inStatement)

Answer 2

Is you PayrollCode_Code numeric? if yes then you don't need to add single quotation for that. And I prefer to use IN statement instead of multiple OR operator.
Dim sCode As String
For Each drv As CListItem In lstnoncash.SelectedItems
sCode &= drv.ItemData & ","
Next
IF sCode.Length > 0 THEN
sCode = sCode.Substring(0,sCode.Length-1);
Dim _SQL As String = "Select SUM(Amount) FROM tblEmployeeTransactions " &
"WHERE PayrollCode_Code IN (" & sCode & ")"
''Execute ur _SQL
END IF