c# - C#，如何使用查询进行搜索

我想搜索一下。我用c＃连接MySQL数据库。以及何时将在表之间创建实体关系图。我想使用查询来查找该特定任务属于特定客户的客户手机。

我尝试这个。

MySqlConnection connection = new MySqlConnection(MyConnectionString);
connection.Open();

try
{
    MySqlCommand cmd = connection.CreateCommand();


    cmd.CommandText = "SELECT *  FROM assignments  WHERE assignments.Customer_ID = customers.Customer_ID;
    //assignments and customers are tables
    MySqlDataAdapter adap = new MySqlDataAdapter(cmd);
    DataSet ds = new DataSet();
    adap.Fill(ds);
    dataGridView5.DataSource = ds.Tables[0].DefaultView;


}
catch (Exception)
{

    //throw;

    MessageBox.Show("Please complete correct the fields");
}

finally
{

    if (connection.State == ConnectionState.Open)
    {

        connection.Clone();

    }
}

谁能帮我？

最佳答案

您的查询似乎是错误的。您需要像这样正确连接表：

cmd.CommandText = "SELECT *  FROM assignments
       inner join Customers on assignments.Customer_ID = customers.Customer_ID";

关于c# - C#，如何使用查询进行搜索，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/29656834/