private void sign_in_Click(object sender, EventArgs e)
{
String username, password;
username = txtName.Text;
password = txtpsd.Text;
String myconn = "server = localhost;port=3306;user=root;password=123456;database=score"; //数据库实例连接字符串
MySqlConnection sq = new MySqlConnection(myconn); //建立连接
sq.Open(); //打开数据库
if (comboBox1.Text == "学生")
{
string sql = string.Format("select count(*) from student where sname='{0}'", username);
MySqlCommand cmd = new MySqlCommand(sql, sq);
int a = Convert.ToInt32(cmd.ExecuteScalar());//返回一个值，看用户是否存在
string sql1 = string.Format("select count(*) from student where spassword='******'", password);
MySqlCommand cmd1 = new MySqlCommand(sql1, sq);
int b = Convert.ToInt32(cmd1.ExecuteScalar());
if (a != 0 && b != 0)
{
成绩查询 form = new 成绩查询();
form.Show();
}
else
{
DialogResult dr = MessageBox.Show("请检查您的用户名或密码是否正确，或注册新用户！", "登录失败!", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (dr == DialogResult.Yes)//打开注册页面
{
注册 form2 = new 注册();
form2.Show();
}
else
{
this.Show();
}
}
}
if (comboBox1.Text == "教师")
{
string sql = string.Format("select count(*) from techer where tname='{0}'", username);
MySqlCommand cmd = new MySqlCommand(sql, sq);
int a = Convert.ToInt32(cmd.ExecuteScalar());//返回一个值，看用户是否存在
string sql1 = string.Format("select count(*) from techer where tpasswoed='{0}'", password);
MySqlCommand cmd1 = new MySqlCommand(sql1, sq);
int b = Convert.ToInt32(cmd1.ExecuteScalar());
if (a != 0 && b != 0)
{
教师 form = new 教师();
form.Show();
}
else
{
DialogResult dr = MessageBox.Show("请检查您的用户名或密码是否正确，或注册新用户！", "登录失败!", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (dr == DialogResult.Yes)//打开注册页面
{
注册 form2 = new 注册();
form2.Show();
}
else
{
this.Show();
}
}
}
if (comboBox1.Text == "管理员")
{
string sql = string.Format("select count(*) from master where mname='{0}'", username);
MySqlCommand cmd = new MySqlCommand(sql, sq);
int a = Convert.ToInt32(cmd.ExecuteScalar());//返回一个值，看用户是否存在
string sql1 = string.Format("select count(*) from master where mpassword='******'", password);
MySqlCommand cmd1 = new MySqlCommand(sql1, sq);
int b = Convert.ToInt32(cmd1.ExecuteScalar());
if (a != 0 && b != 0)
{
管理员 form = new 管理员();
form.Show();
}
else
{
DialogResult dr = MessageBox.Show("请检查您的用户名或密码是否正确，或注册新用户！", "登录失败!", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (dr == DialogResult.Yes)//打开注册页面
{
注册 form2 = new 注册();
form2.Show();
}
else
{
this.Show();
}
}
}
}
private void button4_Click(object sender, EventArgs e)
{
成绩查询 form = new 成绩查询();
form.Show();
}