Check if a table or field exists in a database

Function to check if a table or field exists in an MS Access or SQL Server database.

Introduction

These are two functions I wrote in VB.NET using ADO.NET to check and see if a table or a field exists in a database. It can work with MS Access, or SQL Server, or any other OLE database.

Background

Checking if a table or a field exists in an Access database should be a very simple task, but it can become very complicated with ADO.NET. With DAO or ADO in VB 6.0, this was an extremely easy task. Those who have used it will agree. So, I am posting these functions to help other programmers. Hopefully, it will help out some.

Using the code

Here are the functions:

''' <summary>''' Checks to see if a table exists in Database or not.''' </summary>''' <param name="tblName">Table name to check</param>''' <param name="cnnStr">Connection String to connect to</param>''' <returns>Works with Access or SQL</returns>''' <remarks></remarks>Public Function DoesTableExist(ByVal tblName As String, ByVal cnnStr As String) As Boolean    ' For Access Connection String,    ' use "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" &    ' accessFilePathAndName    ' Open connection to the database    Dim dbConn As New OleDbConnection(cnnStr)    dbConn.Open()        ' Specify restriction to get table definition schema    ' For reference on GetSchema see:    ' http://msdn2.microsoft.com/en-us/library/ms254934(VS.80).aspx    Dim restrictions(3) As String    restrictions(2) = tblName    Dim dbTbl As DataTable = dbConn.GetSchema("Tables", restrictions)    If dbTbl.Rows.Count = 0 Then        'Table does not exist        DoesTableExist = False    Else        'Table exists        DoesTableExist = True    End If    dbTbl.Dispose()    dbConn.Close()    dbConn.Dispose()End Function''' <summary>''' Checks to see if a field exists in table or not.''' </summary>''' <param name="tblName">Table name to check in</param>''' <param name="fldName">Field name to check</param>''' <param name="cnnStr">Connection String to connect to</param>''' <returns></returns>''' <remarks></remarks>Public Function DoesFieldExist(ByVal tblName As String, _                               ByVal fldName As String, _                               ByVal cnnStr As String) As Boolean    ' For Access Connection String,    ' use "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" &    ' accessFilePathAndName    ' Open connection to the database    Dim dbConn As New OleDbConnection(cnnStr)    dbConn.Open()    Dim dbTbl As New DataTable    ' Get the table definition loaded in a table adapter    Dim strSql As String = "Select TOP 1 * from " & tblName    Dim dbAdapater As New OleDbDataAdapter(strSql, dbConn)    dbAdapater.Fill(dbTbl)    ' Get the index of the field name    Dim i As Integer = dbTbl.Columns.IndexOf(fldName)    If i = -1 Then        'Field is missing        DoesFieldExist = False    Else        'Field is there        DoesFieldExist = True    End If    dbTbl.Dispose()    dbConn.Close()    dbConn.Dispose()End Function