[C#]C# 把postgresql 查詢出來的資料丟入DataGridView

一開始我們查出來的資料都是直接用NpgsqlDataReader 來做操作，就像下面這段程式碼為例子。

NpgsqlConnection conn =
    new NpgsqlConnection("Server=127.0.0.1;Port=5432;User Id=postgres;Password=t@ida1234;Database=Demo;");
conn.Open();

NpgsqlCommand command =
    new NpgsqlCommand("select * from shop_sale", conn);

try
{
    NpgsqlDataReader reader = command.ExecuteReader();

    while (reader.Read())
    {
        string shop = reader["shop"].ToString(); ;
        string no = reader["no"].ToString(); ;

        Console.WriteLine(shop + "\t" + no);
    }
}

finally
{
    conn.Close();
}

如果要放進DataGridView中，我們必須先拉一個DataGridView出來，命名為dataGridView1

宣告一個用來存放資料的DataTable

DataTable dt = new DataTable();

用NpgsqlDataReader裡的資料填進DataTable

dt.Load(reader);

指定DataGridView 的資料來源

dataGridView1.DataSource = dt;    

完整程式碼

using System;
using System.ComponentModel;
using System.Data;
using System.Windows.Forms;
using Npgsql;
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        getData();     
    }
    private void getData()
    {
        DataTable dt = new DataTable();
        NpgsqlConnection conn =
            new NpgsqlConnection("Server=127.0.0.1;Port=5432;" +
                "User Id=postgres;Password=t@ida1234;" +
                "Database=Demo;");
        conn.Open();

        NpgsqlCommand command = new
            NpgsqlCommand("select * from shop_sale", conn);

        try
        {
            NpgsqlDataReader reader = command.ExecuteReader();
            dt.Load(reader);
            dataGridView1.DataSource = dt;
        }

        finally
        {
            conn.Close();
        }
    }
}

執行結果