各位大神帮帮忙吧 看看哪里错了

[qq_41504478]

string constr = @"Data Source=.; Initial Catalog=liunian; Integrated Security=True";
string sql = "select * from studentInflo where studentNumber ='"+ textBox1.Text + "'";
MessageBox.Show(sql);
SqlParameter aaa = new SqlParameter("@id", textBox1.Text);
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand(sql, con))
{
cmd.Parameters.Add(aaa);
con.Open();
using (SqlDataReader rdr = cmd.ExecuteReader())
{
textBox2.Text = null;
while (rdr.Read())
{
for (int i = 0; i < rdr.FieldCount; i++)
{
textBox2.AppendText(rdr[i].ToString());
}
textBox2.AppendText("\r\n");
}
}
}
}

[threenewbee]

报什么错？数据库连上了么？查询写对了么？

[圣殿骑士18]

你既然用了SqlParameter 就不应该是 string sql = "select * from studentInflo where studentNumber ='"+ textBox1.Text + "'"; 而是 string sql = "select * from studentInflo where studentNumber =@id";

[轻鸿万里]

string constr = @"Data Source=.; Initial Catalog=liunian; Integrated Security=True"; string sql = "select * from studentInflo where studentNumber ='"+ textBox1.Text + "'"; MessageBox.Show(sql); using (SqlConnection con = new SqlConnection(constr)) { using (SqlCommand cmd = new SqlCommand(sql, con)) { con.Open(); using (SqlDataReader rdr = cmd.ExecuteReader()) { textBox2.Text = null; while (rdr.Read()) { for (int i = 0; i < rdr.FieldCount; i++) { textBox2.AppendText(rdr[i].ToString()); } textBox2.AppendText("\r\n"); } } } } 你干脆改成这样