1 using System;
2 using System.Collections.Generic;
3 using System.ComponentModel;
4 using System.Configuration;
5 using System.Data;
6 using System.Data.SqlClient;
7 using System.Drawing;
8 using System.Linq;
9 using System.Text;
10 using System.Threading.Tasks;
11 using System.Windows.Forms;
12
13 namespace _01SQLAndAdo.Net
14 {
15 public partial class SqlData2DataGirdView : Form
16 {
17 public SqlData2DataGirdView()
18 {
19 InitializeComponent();
20 }
21
22 private void SqlData2DataGirdView_Load(object sender, EventArgs e)
23 {
24
25 string connStr = ConfigurationManager.ConnectionStrings["sql"].ConnectionString;
26 string commandText = @"SELECT TOP 1000 [User_ID]
27 ,[User_Name]
28 ,[User_Gender]
29 ,[User_Age]
30 ,[User_Address]
31 ,[User_Birthday]
32 ,[User_Remark]
33 ,[User_Money]
34 ,[User_GUIDDemo]
35 ,[User_Pwd]
36 FROM[LJK_SQLServerDB].[dbo].[User_Info]";
37 using (SqlConnection conn = new SqlConnection(connStr))
38 {
39 using (SqlDataAdapter adapter = new SqlDataAdapter(commandText, connStr))
40 {
41 //DataSet方式，查询多张表的时候应用
42 //DataSet dataSet=new DataSet();
43 //adapter.Fill(dataSet,"demo");
44 //this.dgvUserInfo.DataSource = dataSet.Tables["demo"];
45
46 DataTable dataTable = new DataTable();
47 //填充之前不需要打开数据库连接，Adaper会自动打开连接，并执行SQL
48 //Fill方法内部：
49 //1. 先判断SqlConnection是否初始化，如果没有打开链接，那么打开连接。
50 //2. 初始化一个Select(commandText) SqlCommand对象
51 //3. 通过cmd对象执行，然后返回一个SqlReader对象。
52 //4. 读取数据库中的数据，然后填充到DataTable上去
53 adapter.Fill(dataTable); //把数据库中的数据 填充到 内存表中
54 //把内存表显示到DataGirdView上去
55 // this.dgvUserInfo.DataSource = dataTable;
56
57 // var o = dataTable.Rows[0][1];
58
59 // dataRow["列名"]; //弱类型
60 //user.UserInfo //强类型，出错概率下降
61 List<UserInfo> userInfoList = new List<UserInfo>();
62 foreach (DataRow dataRow in dataTable.Rows)
63 {
64 Console.WriteLine(dataRow["User_Id"] + " " + dataRow[0]);
65 Console.WriteLine(dataRow["User_Name"] + " " + dataRow[1]);
66 Console.WriteLine(dataRow["User_Age"] + " " + dataRow[2]);
67 Console.WriteLine(dataRow["User_Pwd"] + " " + dataRow[3]);
68 UserInfo userInfo = new UserInfo();
69 userInfo.UserId = int.Parse(dataRow["User_ID"].ToString());
70 userInfo.UserName = dataRow["User_Name"].ToString();
71 if (!string.IsNullOrEmpty(dataRow["User_Age"].ToString()))
72 {
73 userInfo.UserAge = int.Parse(dataRow["User_Age"].ToString());
74 // userInfo.UserAge = dataRow["User_Age"].ToString();
75 // userInfo.UserAge = 1;
76 }
77 else
78 {
79 userInfo.UserAge = 0;
80 }
81
82 if (!string.IsNullOrEmpty(dataRow["User_Pwd"].ToString()))
83 {
84 userInfo.UserPwd = int.Parse(dataRow["User_Pwd"].ToString());
85 }
86 else
87 {
88 userInfo.UserPwd = 11;
89 }
90
91 userInfoList.Add(userInfo);
92
93
94 //把DataTabel的数据转成List<UserInfo>
95
96 }
97
98 this.dgvUserInfo.DataSource = userInfoList;
99
100 }
101
102 }
103
104
105 }
106 }
107 }
