如何将多个表中的数据显示到dataGridView

Question

我想在一个 dataGridView 中显示电话簿和电子邮件数据。问题是它只会显示电子邮件表

MySqlConnection connection = new MySqlConnection(MyConnectionString);
connection.Open();
try
{
    MySqlCommand cmd = connection.CreateCommand();
    cmd.CommandText = "SELECT * FROM phonebook";
    cmd.CommandText = "SELECT * FROM email";
    MySqlDataAdapter adap = new MySqlDataAdapter(cmd);
    DataSet ds = new DataSet();
    adap.Fill(ds);
    dataGridView1.DataSource = ds.Tables[0].DefaultView;
}
catch(Exception ex)
{
    MessageBox.Show(ex.Message);
}
finally
{
    if (connection.State == ConnectionState.Open)
    {
        connection.Clone();
    }
}

Answer 1

您需要连接两个表并获取如下结果

using(MySqlConnection connection = new MySqlConnection(MyConnectionString))
using(MySqlCommand cmd = connection.CreateCommand())
{
    connection.Open();
    cmd.CommandText = "SELECT pb.Id, pb.Name, pb.MobileNo, e.email FROM phonebook pb INNER JOIN email e ON e.Id= pb.Id";
    MySqlDataAdapter adap = new MySqlDataAdapter(cmd);
    DataSet ds = new DataSet();
    adap.Fill(ds);
    dataGridView1.DataSource = ds.Tables[0].DefaultView;
}