条件表达式Access 2013中的数据类型不匹配

Question

OleDbCommand computerStatus = new OleDbCommand("update Computer SET Status= 'Occupied' where PcNumber='" + cboComputerNo.Text + "'", con);
computerStatus.ExecuteNonQuery();

this is my code. pcNumber is autonumber i am getting an error it wants me to change the data type to string but i need it to be autonumber.

Answer 1

AutoNumber is auto number . Since it is a numerical value, you don't need to use single quotes with it.

But more important, you should always use parameterized queries . This kind of string concatenations are open for SQL Injection attacks.

Also use using statement to dispose your OleDbConnection and OleDbCommand .

using(OleDbConnection con = new OleDbConnection(conString))
using(OleDbCommand computerStatus = con.CreateCommand())
{
    computerStatus.CommandText = "update Computer SET Status= ? where PcNumber = ?";
    computerStatus.Parameters.AddWithValue("@status", "Occupied");
    computerStatus.Parameters.AddWithValue("@number", cboComputerNo.Text);
    computerStatus.ExecuteNonQuery();
}

As LarsTech pointed, you may wanna check your cboComputerNo.Text string is a valid integer with using Int.TryParse method .