SQL in Excel VBA - Best Practices

How to use ADODB.Connection in VBA?

Requirements:

Add following references to the project:

Microsoft ActiveX Data Objects 2.8 Library

Microsoft ActiveX Data Objects Recordset 2.8 Library

Declare variables

Private mDataBase As New ADODB.Connection
Private mRS As New ADODB.Recordset
Private mCmd As New ADODB.Command

Create connection

a. with Windows Authentication

Private Sub OpenConnection(pServer As String, pCatalog As String)
    Call mDataBase.Open("Provider=SQLOLEDB;Initial Catalog=" & pCatalog & ";Data Source=" & pServer & ";Integrated Security=SSPI")
    mCmd.ActiveConnection = mDataBase
End Sub

b. with SQL Server Authentication

Private Sub OpenConnection2(pServer As String, pCatalog As String, pUser As String, pPsw As String)
    Call mDataBase.Open("Provider=SQLOLEDB;Initial Catalog=" & pCatalog & ";Data Source=" & pServer & ";Integrated Security=SSPI;User ID=" & pUser & ";Password=" & pPsw)
    mCmd.ActiveConnection = mDataBase
End Sub

Execute sql command

Private Sub ExecuteCmd(sql As String)
    mCmd.CommandText = sql
    Set mRS = mCmd.Execute
End Sub

Read data from record set

Private Sub ReadRS()
    Do While Not (mRS.EOF)
        Debug.Print "ShipperID: " & mRS.Fields("ShipperID").Value & " CompanyName: " & mRS.Fields("CompanyName").Value & " Phone: " & mRS.Fields("Phone").Value
        Call mRS.MoveNext
    Loop
End Sub

Close connection

Private Sub CloseConnection()
    Call mDataBase.Close
    Set mRS = Nothing
    Set mCmd = Nothing
    Set mDataBase = Nothing
End Sub

How to use it?

Public Sub Program()
    Call OpenConnection("ServerName", "NORTHWND")
    Call ExecuteCmd("INSERT INTO [NORTHWND].[dbo].[Shippers]([CompanyName],[Phone]) Values ('speedy shipping','(503) 555-1234')")
    Call ExecuteCmd("SELECT * FROM [NORTHWND].[dbo].[Shippers]")
    Call ReadRS
    Call CloseConnection
End Sub

Result

ShipperID: 1 CompanyName: Speedy Express Phone: (503) 555-9831

ShipperID: 2 CompanyName: United Package Phone: (503) 555-3199

ShipperID: 3 CompanyName: Federal Shipping Phone: (503) 555-9931

ShipperID: 4 CompanyName: speedy shipping Phone: (503) 555-1234