System.Data.OleDb.OleDbException:条件表达式中的数据类型不匹配

这是我的代码:

OleDbCommand Cmd = new OleDbCommand();
Cmd.Connection = MyConn;
Cmd.CommandText = "SELECT * FROM catalogue WHERE id = '" + questionid + "'";

OleDbDataReader read = Cmd.ExecuteReader();

int id = 0;

while (read.Read())
{
    id = Convert.ToInt32(read["id"]);
}

这是它给我的错误:

Line 27:         Cmd.CommandText = "SELECT * FROM catalogue WHERE id = '" + questionid + "'";
Line 28: 
Line 29:         OleDbDataReader read = Cmd.ExecuteReader(); // The error is here
Line 30: 
Line 31:         int id = 0;

我知道在Stack Overflow上还有另一个关于同一问题的问题,但它似乎没有解决我的问题(它可以解决你的问题,所以我放了一个链接).