I'm getting a "Unreachable code detected" message in Visual Studio at the point con.close() in my code below. Can you spot what I've done wrong?
private int chek1(String insert)
{
OleDbConnection con = new OleDbConnection("provider=microsoft.jet.oledb.4.0;data source=d:\\sdb.mdb");
OleDbCommand com = new OleDbCommand("select count(*) from sn where sn='" + insert + "\'", con);
con.Open();
int po = (int)com.ExecuteScalar();
if (po > 0)
return 1;
else
return 0;
con.Close();
}
Your code could be like this:
private int check(string sn)
{
using (OleDbConnection connection = new OleDbConnection("provider=microsoft.jet.oledb.4.0;data source=d:\\sdb.mdb"))
using (OleDbCommand command = connection.CreateCommand())
{
command.CommandText = "SELECT COUNT(*) FROM sn WHERE sn=?";
command.Parameters.Add("@sn", sn));
con.Open();
return ((int)com.ExecuteScalar() > 0) ? 1 : 0;
}
}