Question

C# 数据库问题 cmd.Parameters.Add("@id", i); ……已过期…… 这是什么情况？

string ConStr = "Provider=Microsoft.Jet.OLEDB.4.0;data source=Location.mdb";
OleDbConnection con = new OleDbConnection(ConStr);
con.Open();
int i = Convert.ToInt16(textBox1.Text);
OleDbCommand cmd = new OleDbCommand("select * Form data where ID>@id",con );
cmd.Parameters.Add("@id", i);
OleDbDataReader reader = cmd.ExecuteReader();
reader.Read();
//textBox1.Text = reader[0].ToString();
textBox2.Text = reader[1].ToString();
textBox3.Text = reader[2].ToString();
textBox4.Text = reader[3].ToString();
textBox5.Text = reader[4].ToString();
textBox6.Text = reader[5].ToString();
textBox7.Text = reader[6].ToString();
reader.Close();
con.Close();
OleDbDataReader reader = cmd.ExecuteReader();

是这个已过期，不是cmd.Parameters.Add("@id", i);

Answer 1

cmd.Parameters.Add("@id", i);

改成
cmd.Parameters.AddWithValue("@id", i);