I am trying to retrieve a maximum value from sql - vb.net
This is my code: I get this error:
Unable to cast object of type 'System.DBNull' to type 'Oracle.DataAccess.Client.OracleDataReader'
Please help. :(
Dim cmd2 As New OracleCommand
cmd2.Connection = conn
'SELECT MAX(LASTNO) FROM d001005 where lbrcode = '104' and CODE1 = 'CASH' and lnodate = '14-NOV-08'
Dim datepara As String = Date.Now.ToString("dd-MMM-yy")
'datepara = "14-NOV-08"
cmd2.CommandText = "SELECT MAX(LASTNO) FROM d001005 where lbrcode = '" + lbr + "' and CODE1 = 'CASH' and lnodate = '" + datepara + "'"
cmd2.CommandType = CommandType.Text
Dim dr2 As OracleDataReader = cmd2.ExecuteScalar
Dim result As Decimal = dr2.Item("LASTNO")
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