密码修改的代码怎么写?(C#+sql2000)

Question

先输入原始用户名和密码,再输入新密码,点修改.

Answer 1

update table set username='新' pwd='新' where username = '原' and password='原'

Answer 2

string conn=GetConnectionString();            string name = textBox1.Text.ToString().Trim();
            string oldpsw = textBox2.Text.ToString().Trim();
            string newpsw1 = textBox3.Text.ToString().Trim();
            string newpsw2 = textBox4.Text.ToString().Trim();            textBox1.Focus();            if (name == "")
            {
                MessageBox.Show("请输入用户名！");
                textBox1.Focus();
            }
            else if (oldpsw == "")
            {
                MessageBox.Show("请输入密码！");
                textBox2.Focus();
            }
            else if (newpsw1 == "")
            {
                MessageBox.Show("请输入新密码！");
                textBox3.Focus();
            }
            else if (newpsw2 == "")
            {
                MessageBox.Show("请输入新密码");
                textBox4.Focus();
            }
            else if (newpsw1 != newpsw2)
            {
                MessageBox.Show("两次新密码不符");
                textBox3.Focus();
            }
            else
            {                string queryString = "SELECT name,psw FROM admin";
                bool flag = false;
                using (OleDbConnection connection = new OleDbConnection(conn))
                {
                    OleDbCommand command = new OleDbCommand(queryString, connection);
                    connection.Open();
                    OleDbDataReader reader = command.ExecuteReader();
                    while (reader.Read())
                    {
                        if (name == reader[0].ToString().Trim() && MD5Encrypt(oldpsw) == reader[1].ToString().Trim())
                        {
                            flag = true;
                            break;
                        }                    }
                    reader.Close();
                }                if (flag == false)
                {
                    MessageBox.Show("用户名或密码错误！");
                    this.textBox1.Focus();
                }
                else
                {
                    string newpsw = MD5Encrypt(newpsw1);
                    string query = "UPDATE admin SET psw='" + newpsw + "' WHERE name='" + name + "'";
                    using (OleDbConnection connection = new OleDbConnection(conn))
                    {
                        connection.Open();
                        OleDbCommand command = new OleDbCommand(query, connection);
                        command.ExecuteNonQuery();
                    }
                    MessageBox.Show("修改成功!");
                    this.Close();
                }
            }

Answer 3

页面框框都用RequireFieldValidator验证就行了，至于更新语句就参考楼上的，一楼的语句set 两项之间忘了逗号。