VBA macro save SQL query in a csv file - vba

Question

I am working on a VBA macro which connects to my database on SQL Server and run some queries and save the results on CSV files... it works fine just when the queries returns data but i have days where the query doesn't return any results, just an empty table. I made a temporary solution based on checking the date and according it the macro runs that query or no... I want to make it other way now in my code so that i don't need to change the date everytime manually...
I tried these solutions :
If (objMyRecordset.EOF = False) Or (objMyRecordset.BOF = False) Then
Also this
If objMyRecordset.RecordCount <> 0 Then
but the problem is my Recordset is empty because the query doesn't return any rows so it shows me error in objMyRecordset.Open
I want to add a line of code like this for example :
'// Pseudo Code
If (the query doesn't return result) Then
( just the headers will be save on my file )
Else
(do the rest of my code)
End If
Here is my code. Any suggestions please ? Thank you very much.
Sub Load_after_cutoff_queryCSV()
Dim objMyConn As ADODB.Connection
Dim objMyCmd As ADODB.Command
Dim objMyRecordset As ADODB.Recordset
Dim fields As String
Dim i As Integer
Set objMyConn = New ADODB.Connection
Set objMyCmd = New ADODB.Command
Set objMyRecordset = New ADODB.Recordset
'Open Connection
objMyConn.ConnectionString = "Provider=SQLOLEDB;Data Source=*****;User ID=*****;Password=*****;"
objMyConn.Open
'Set and Excecute SQL Command
Set objMyCmd.ActiveConnection = objMyConn
objMyCmd.CommandText = "SELECT * FROM [vw_X86_LOAD_AFTER_CUTOFF_REPORT_GAMMA]"
objMyCmd.CommandType = adCmdText
'Open Recordset
Set objMyRecordset.Source = objMyCmd
objMyRecordset.Open
Workbooks.Open Filename:="C:\Reports\load_after_cutoff_postGamma.csv"
Workbooks("load_after_cutoff_postGamma.csv").Sheets("load_after_cutoff_postGamma").Activate
ActiveSheet.Range("A2").CopyFromRecordset objMyRecordset
For i = 0 To objMyRecordset.fields.Count - 1
Worksheets("load_after_cutoff_postGamma").Cells(1, i + 1) = objMyRecordset.fields(i).name
Next i
Workbooks("load_after_cutoff_postGamma.csv").Sheets("load_after_cutoff_postGamma").Cells.EntireColumn.AutoFit
Workbooks("load_after_cutoff_postGamma.csv").Close SaveChanges:=True
MsgBox "Your file has been saved as load_after_cutoff_postGamma.csv"

Answer 1

If you experience problems connecting to your server then this is due to any of the following:
an incorrect connection string
incorrect credentials
the server is not reachable (for example: network cable disconnected)
the server is not up and running
Sending a query to a server which results in an empty recordset is not a reason for an ADODB.Connection to fail.
Here is a little bit of code for you to try and debug the connection in a first step and then the query in a second step:
Option Explicit
Public Sub tmpSO()
Dim strSQL As String
Dim strServer As String
Dim strDatabase As String
Dim OutMail As Outlook.MailItem
Dim rstResult As ADODB.Recordset
Dim conServer As ADODB.Connection
Dim OutApp As Outlook.Application
strServer = "."
strDatabase = "master"
Set conServer = New ADODB.Connection
conServer.ConnectionString = "PROVIDER=SQLOLEDB; " _
& "DATA SOURCE=" & strServer & ";" _
& "INITIAL CATALOG=" & strDatabase & ";" _
& "User ID='UserNameWrappedInSingleQuotes'; " _
& "Password='PasswordWrappedInSingleQuotes'; "
On Error GoTo SQL_ConnectionError
conServer.Open
On Error GoTo 0
strSQL = "set nocount on; "
strSQL = strSQL & "select * "
strSQL = strSQL & "from sys.tables as t "
strSQL = strSQL & "where t.name = ''; "
Set rstResult = New ADODB.Recordset
rstResult.ActiveConnection = conServer
On Error GoTo SQL_StatementError
rstResult.Open strSQL
On Error GoTo 0
If Not rstResult.EOF And Not rstResult.BOF Then
ThisWorkbook.Worksheets(1).Range("A1").CopyFromRecordset rstResult
' While Not rstResult.EOF And Not rstResult.BOF
' 'do something
' rstResult.MoveNext
' Wend
Else
'https://msdn.microsoft.com/en-us/library/windows/desktop/ms675546(v=vs.85).aspx
Select Case conServer.State
'adStateClosed
Case 0
MsgBox "The connection to the server is closed."
'adStateOpen
Case 1
MsgBox "The connection is open but the query did not return any data."
'adStateConnecting
Case 2
MsgBox "Connecting..."
'adStateExecuting
Case 4
MsgBox "Executing..."
'adStateFetching
Case 8
MsgBox "Fetching..."
Case Else
MsgBox conServer.State
End Select
End If
Set rstResult = Nothing
Exit Sub
SQL_ConnectionError:
MsgBox "Couldn't connect to the server. Please make sure that you have a working connection to the server."
Set OutApp = New Outlook.Application
Set OutMail = OutApp.CreateItem(0)
With OutMail
.Subject = "Problems connecting to database '" & strDatabase & "' hosted on the server '" & strServer & "'"
.HTMLBody = "<span style=""font-size:10px"">---Automatically generated Error-Email---" & _
"</span><br><br>Error report from the file '" & _
"<span style=""color:blue"">" & ThisWorkbook.Name & _
"</span>' located and saved on '<span style=""color:blue"">" & _
ThisWorkbook.Path & "</span>'.<br>" & _
"Excel is not able to establish a connection to the server. Technical data to follow." & "<br><br>" & _
"Computer Name: <span style=""color:green;"">" & Environ("COMPUTERNAME") & "</span><br>" & _
"Logged in as: <span style=""color:green;"">" & Environ("USERDOMAIN") & "/" & Environ("USERNAME") & "</span><br>" & _
"Domain Server: <span style=""color:green;"">" & Environ("LOGONSERVER") & "</span><br>" & _
"User DNS Domain: <span style=""color:green;"">" & Environ("USERDNSDOMAIN") & "</span><br>" & _
"Operating System: <span style=""color:green;"">" & Environ("OS") & "</span><br>" & _
"Excel Version: <span style=""color:green;"">" & Application.Version & "</span><br>" & _
"<br><span style=""font-size:10px""><br>" & _
"<br><br>---Automatically generated Error-Email---"
.Display
End With
Set OutMail = Nothing
Set OutApp = Nothing
Exit Sub
SQL_StatementError:
MsgBox "There seems to be a problem with the SQL Syntax in the programming."
Set OutApp = New Outlook.Application
Set OutMail = OutApp.CreateItem(0)
With OutMail
.Subject = "Problems with the SQL Syntax in file '" & ThisWorkbook.Name & "'."
.HTMLBody = "<span style=""font-size:10px"">" & _
"---Automatically generated Error-Email---" & _
"</span><br><br>" & _
"Error report from the file '" & _
"<span style=""color:blue"">" & _
ActiveWorkbook.Name & _
"</span>" & _
"' located and saved on '" & _
"<span style=""color:blue"">" & _
ActiveWorkbook.Path & _
"</span>" & _
"'.<br>" & _
"It seems that there is a problem with the SQL-Code within trying to upload an extract to the server." & _
"SQL-Code causing the problems:" & _
"<br><br><span style=""color:green;"">" & _
strSQL & _
"</span><br><br><span style=""font-size:10px"">" & _
"---Automatically generated Error-Email---"
.Display
End With
Set OutMail = Nothing
Set OutApp = Nothing
Exit Sub
End Sub
Note, that the above code clearly distinguishes between (first) connecting to the server and then (afterwards) issuing a query to the server to retrieve some data. Both steps are separated and there is a different error handler for either case.
Furthermore, the above sample code also results in an empty recordset being returned. But the code is able to handle that incident with yet another error handler.
If the connection fails or if the SQL syntax being sent to the server contains error(s) then the above code will automatically generate an error email (using Outlook) with some details for you to check the connection and the SQL syntax.

Answer 2

you should go with your .EOF solution. Here is an example of mine, which I use regularly.
Sub AnySub()
''recordsets
Dim rec as ADODB.Recordset
''build your query here
sSql = "SELECT * FROM mytable where 1=0" ''just to have no results
''Fire query
Set rec = GetRecordset(sSql, mycnxnstring)
''and then loop throug your results, if there are any
While rec.EOF = False
''do something with rec()
rec.MoveNext
Wend
End sub
Here the Function GetRecordset() is given by:
Function GetRecordset(strQuery As String, connstring As String) As Recordset
Dim DB As ADODB.Connection
Dim rs As ADODB.Recordset
Set DB = New ADODB.Connection
With DB
.CommandTimeout = 300
.ConnectionString = connstring
.Open
End With
Set GetRecordset = DB.Execute(strQuery)
End Function
Hope this helps.