update warning msg for Read-OleDbData

Public/Read-OleDbData.ps1

@@ -36,28 +36,15 @@ function Read-OleDbData {
         [String] $SqlStatement   
     )
     
-    if ($IsLinux -or $IsMacOS) {
-        #todo: possibly add support for linux/mac somehow. i haven't researched this at all as i 
-        #      don't have a need for that and i'm not sure anyone else would in this context, but it does
-        #      appear that once upon a time mono had support for oledb, so maybe it is (or was) supported.
-        #      mono link here: https://www.mono-project.com/archived/ole_db/ 
-        Write-Error "Read-OleDbData only runs on Windows"
+    try {
+        if ((New-Object system.data.oledb.oledbenumerator).GetElements().SOURCES_NAME -notcontains "Microsoft.ACE.OLEDB.12.0") {
+            Write-Warning "Microsoft.ACE.OLEDB.12.0 provider is missing! You will not be able to query Excel files without it. Please install from https://www.microsoft.com/en-us/download/details.aspx?id=54920"
+        }
+    }
+    catch {
+        Write-Error "System.Data.OleDb is not working or you are on an unsupported platform."
         return
     }
-
-    #todo: add checks for dotnet libs
-    #todo: possibly add checks for ace drivers, but maybe only needed if we want to restrict usage.
-    #      i currently just pass through the query and connection string so user is only limited by
-    #      their own machine setup, but they have to check for those dependencies themselves.
-    #todo: possibly try/catch. i personally do not do this, as i let them throw naturally and catch
-    #      them/handle them outside of this function.
-    #todo: possibly allow for DataSets instead of just DataTable. I used to use a similar method before
-    #      switching to the sqlcmd module and use datasets as I had multiple tables coming back from
-    #      sql sometimes. i think in this case, it's best to just keep it simple, but maybe someone
-    #      out there would prefer to be able to get multiple tables back. i have not tested that
-    #      with the OleDbDataAdapter.
-    #todo: possibly just return the datatable, i do it as below because i prefer to simplify the output
-    #      and get rid of the extra fields that come back with the datatable or rows.
     
     $DataTable = new-object System.Data.DataTable
     $DataAdapter = new-object System.Data.OleDb.OleDbDataAdapter $SqlStatement, $ConnectionString