Question

C#里面为什么说列名无效

SqlConnection conn = new SqlConnection("Server=.;Database=student;Trusted_Connection=SSPI");
conn.Open();
string sql = "select * from UserInfo where UserName='"+txtUsername.Text.Trim()+"'and PassWord='"+txtPassword.Text.Trim()+"'";
SqlCommand cmd = new SqlCommand(sql,conn);
SqlDataReader dr = cmd.ExecuteReader();
dr.Read();
if (dr.HasRows)
{
frmMain fr = new frmMain();
fr.Show();
this.Hide();
}
else
{
MessageBox.Show("您输入的用户名或密码错误");
}
dr.Close();
conn.Close();
一开始可以执行，但我重新创建了一个表，而且把代码里表名改了过来，却不能执行了 提示PassWord列名无效

Answer 1

txtUsername.Text.Trim()+"'and PassWord
应该是
txtUsername.Text.Trim()+"' and PassWord