Question

I’m trying to compare a string (network ID) and using a SQL Like command, return the numbers of rows affected (if the user name was found or not) however in my code I’m always getting ” -1 ” which i can not find why, the username is correct and found in the SQL table by running a query in SQL Server Mgt.

Try
        Dim Con As New SqlConnection
        Con.ConnectionString = "Data Source=WCRDUSMJEMPR9\SQLEXPRESS;Initial Catalog=MicroDB;Integrated Security=True"
        Con.Open()
        Dim SQL2 As String
        SQL2 = "SELECT * from MicroDB_Users WHERE Users LIKE '+@Usercheck+'"
        Dim cmd2 As New SqlCommand(SQL2, Con)
        cmd2.Parameters.AddWithValue("@Usercheck", TextBox1.Text)
        Dim obj2 = cmd2.ExecuteNonQuery
        Con.Close()
        If obj2 > 0 Then
            MsgBox(obj2)
            Response.Redirect("~\ControlCharts\AddData_Control.aspx")
            Label7_Control.Visible = False
        Else
            MsgBox(obj2)
            Label7_Control.Text = ("You are not authorized to Add Data")
            Label7_Control.Visible = True
        End If
    Catch ex As Exception
        MsgBox(Err.Description)

As you can see, i;m using a IF to compare if the user was found ( 1 row affected) or if it was not found ( 0 rows affected).

Answer 1

ExecuteNonQuery is used for insert,update or delete queries only. So you either have to use COUNT in your query and use ExecuteScalar or use ExecuteReader and the reader’s HasRows property.

Using var reader = cmd2.ExecuteReader()
    If reader.HasRows Then
        ' ...
    Else
        ' ...
    End If
End Using

ExecuteNonQuery:

For UPDATE, INSERT, and DELETE statements, the return value is the
number of rows affected by the command. When a trigger exists on a
table being inserted or updated, the return value includes the number
of rows affected by both the insert or update operation and the number
of rows affected by the trigger or triggers. For all other types of
statements, the return value is -1. If a rollback occurs, the return
value is also -1.

Update: Apart from that you’re using the LIKE operator and the parameter incorrectly. Instead of

SQL2 = "SELECT * from MicroDB_Users WHERE Users LIKE '+@Usercheck+'"
cmd2.Parameters.AddWithValue("@Usercheck", TextBox1.Text)

use this approach

SQL2 = "SELECT * from MicroDB_Users WHERE Users LIKE @Usercheck"
cmd2.Parameters.AddWithValue("@Usercheck", string.Format("%{0}%", TextBox1.Text))