VB.net - Check SQL Field to see if Bit is Set - sql

Question

There is a bit field in my SQL table that I need to update to 1 if it's set at 0. I have the code written to set the field for every entry, but I need to check to see if it's at 0 already first so I can log what is changed.
Here's what I have already:
Public Function Update_User_to_TR(ByVal strUserName As String) As String
Dim myUserName As String = strUserName.Trim
Dim myReturn As String
Try
Dim sql As New SQL
Dim strQuery As String
strQuery = "Update dbo.USERS set user_field_Department_TR = 1 where USER_NAME = '" & myUserName & "'"
myReturn = sql.SQLUpdateWT(strQuery)
Catch ex As Exception
myReturn = ex.ToString
MsgBox(myReturn)
End Try
Return myReturn
End Function

Answer 1

You should upgrade to a stored procedure or a function, in this case, but here is a sample query.
"Declare #WillUpdate bit;Set #WillUpdate = 0;" & _
"If Exists(Select user_name from dbo.Users where user_name ='" & myUserName & _
"' and user_field_department_tr = 0 " & _
" Begin " & _
" Update dbo.USERS set user_field_Department_TR = 1 where USER_NAME = '" & myUserName & "';" & _
" Insert Into MyLog(field1, field2) " & _
" Values('sampledata', 'field was updated from 0 to 1');" & _
" End"
But please read the other comments and learn about sql injection and how it's bad, then learn how to use parameterized queries such as with ADO.NET.