Dynamically Add Fields in Access Saved Query - sql

Question

I have a ComboBox named ComboBox_Calculations in my program that is filled with calculations (ex. Current_Ratio, Total_Debt_To_Assets_Ratio). ComboBox_Calculations is actually populated by using the contents of a field in a tabled called Criteria in my Access Database.
I need to create a saved query called Calculations_Quarterly. The query needs to have fields of Ticker, [Year], Period and then one field for every item in ComboBox_Calculations. So for this example I would also need fields named Current_Ratio and Total_Debt_To_Assets_Ratio.
Here is what my tables look like so far:
Criteria
Calculations_Quarterly
Here is the code I have that adds one field at a time (in this case Current_Ratio. But I do not know how add a column for every item in ComboBox_Calculations
con.Open()
Dim dr As OleDbDataReader
Dim cmd6 As New OleDb.OleDbCommand("SELECT Calculation, [Interval], Formula FROM Criteria", con)
dr = cmd6.ExecuteReader
dr.Read()
Dim Calculation = dr("Calculation").ToString
Dim Interval = dr("Interval").ToString
Dim Formula = dr("Formula").ToString
Dim Where_Statement As String
If Interval = "Daily" Then
Where_Statement = "WHERE Historical_Stock_Prices.[Date] < " & DateTime.Now.Date & ""
ElseIf Interval = "MRQ" Then
Where_Statement = "WHERE Income_Statements.Period < 5"
ElseIf Interval = "TTM" Then
Where_Statement = "WHERE Income_Statements.Period < 5"
ElseIf Interval = "5 Year" Then
Where_Statement = "WHERE Income_Statements.Period = 5"
Else
Where_Statement = ""
End If
Try
Dim cmd2 As OleDbCommand = New OleDbCommand("CREATE PROC " & Calculation & " AS SELECT Income_Statements.Ticker, Income_Statements.[Year], Income_Statements.Period, " & Formula & " AS " & Calculation & " FROM Income_Statements INNER JOIN Balance_Sheets ON (Income_Statements.Ticker = Balance_Sheets.Ticker) AND (Income_Statements.[Year] = Balance_Sheets.[Year]) AND (Income_Statements.Period = Balance_Sheets.Period)" & Where_Statement & "", con)
cmd2.ExecuteNonQuery()
Catch ex As Exception
Finally
Dim cmd2a As OleDbCommand = New OleDbCommand("DROP PROCEDURE " & Calculation & "", con)
cmd2a.ExecuteNonQuery()
Dim cmd2b As OleDbCommand = New OleDbCommand("CREATE PROC " & Calculation & " AS SELECT Income_Statements.Ticker, Income_Statements.[Year], Income_Statements.Period, " & Formula & " AS " & Calculation & " FROM Income_Statements INNER JOIN Balance_Sheets ON (Income_Statements.Ticker = Balance_Sheets.Ticker) AND (Income_Statements.[Year] = Balance_Sheets.[Year]) AND (Income_Statements.Period = Balance_Sheets.Period)" & Where_Statement & "", con)
cmd2b.ExecuteNonQuery()
End Try
con.Close

Answer 1

I couldnt find the name of you combobox or how it is filled so assuming it is named Combo1, and you filled it using Combo1.Items.Add("..."), you would want something like this:
Dim sb as new System.Text.StringBuilder("")
For each s as string in Combo1.Items
sb.Append("," & s)
Next
And then in your SQL:
Dim cmd2 As OleDbCommand = New OleDbCommand("CREATE PROC " & Calculation & " AS SELECT Income_Statements.Ticker, Income_Statements.[Year], Income_Statements.Period, " & Formula & " AS " & Calculation & sb.ToString & " FROM Income_Statements INNER JOIN Balance_Sheets ON (Income_Statements.Ticker = Balance_Sheets.Ticker) AND (Income_Statements.[Year] = Balance_Sheets.[Year]) AND (Income_Statements.Period = Balance_Sheets.Period)" & Where_Statement & "", con)