C# Visual Studio - 将 SQL 表数据输出到 Datagridview

Posted 2023-05-08

【中文标题】C# Visual Studio - 将 SQL 表数据输出到 Datagridview

【英文标题】：C# Visual Studio - Outputting SQL table data to Datagridview

【发布时间】：2016-03-10 13:25:25

【问题描述】：

抱歉，如果这已涵盖。我似乎找到的例子比我需要的更复杂

当单击“显示所有记录”按钮时，我试图将 SQL 表的全部内容输出到 DatagridView

我遇到了一些麻烦，这是我目前遇到的情况

  private void Button_Click_2(object sender, RoutedEventArgs e)
        
            

                string query = "select * from student";
                SqlCommand cmd = new SqlCommand(query, con);
                con.Open();


                SqlDataAdapter da = new SqlDataAdapter(cmd);

                da.Fill(DataGridView);
                con.Close();
                da.Dispose();
            

如果您需要参考，这是我的所有代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Data.SqlClient;
using System.Text.RegularExpressions;

namespace WpfApplication4

    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    
        SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True");



        public MainWindow()
        
            InitializeComponent();
            establishConnection();


        

        private void Button_Click(object sender, RoutedEventArgs e)
        


            Boolean postSuccess = false;

            if (validation() == true)
            

                SqlCommand details = new SqlCommand("INSERT INTO Student (Firstname, LastName, MatriculationNo, GradeOne, GradeTwo, GradeThree) VALUES (@FirstName, @LastName, @MatriculationNo, @GradeOne, @GradeTwo, @GradeThree)", con);
                details.Parameters.AddWithValue("@FirstName", firstnameTextbox.Text);
                details.Parameters.AddWithValue("@LastName", lastnameTextbox.Text);
                details.Parameters.AddWithValue("@MatriculationNo", matriculationnoTextbox.Text);
                details.Parameters.AddWithValue("@GradeOne", Component1Textbox.Text);
                details.Parameters.AddWithValue("@GradeTwo", Component2Textbox.Text);
                details.Parameters.AddWithValue("@GradeThree", Component3Textbox.Text);
                con.Open();
                details.ExecuteNonQuery();
                postSuccess = true;

                if (postSuccess)
                
                    MessageBox.Show("Details entered succesfully!");
                    firstnameTextbox.Clear();
                    lastnameTextbox.Clear();
                    matriculationnoTextbox.Clear();
                    Component1Textbox.Clear();
                    Component2Textbox.Clear();
                    Component3Textbox.Clear();

                

                else
                
                    MessageBox.Show("Data not entered succesfully, please check DB connection");
                
                con.Close();
            

        
        private void establishConnection()
        
            try
            
                con.Open();
                System.Diagnostics.Debug.Print("Connected to SQL database");

                connectionLabel.Content = "Connected to SQL Database";

                con.Close();
            
            catch (Exception)
            

                connectionLabel.Content = "not connected to sql database";
            
        

        private void Button_Click_1(object sender, RoutedEventArgs e)
        
            firstnameTextbox.Clear();  //Clears the first name textbox
            lastnameTextbox.Clear();   //Clears the last name textbox
            matriculationnoTextbox.Clear(); //Clears the Matriculation Number textbox
            Component1Textbox.Clear(); //Clears the component one textbox
            Component2Textbox.Clear(); //Clears the component two textbox
            Component3Textbox.Clear(); //Clears the component three textbox
        


        private Boolean validation()
        
            if (!Regex.Match(firstnameTextbox.Text, "^[A-Z][a-zA-Z]*$").Success)
            
                MessageBox.Show("Please Enter a valid First Name");
                firstnameTextbox.Clear();
                return false;
            
            else
            
                return true;
            

        

        private void Button_Click_3(object sender, RoutedEventArgs e)
        
            con.Open(); 
            string sql = @"DELETE FROM Student;"; //Deleting all from Student table
            SqlCommand purge = new SqlCommand(sql, con);
            MessageBox.Show("Are you sure you want to purge the entire contents of the database?"); //Prompting user to make sure they want to delete
            purge.ExecuteNonQuery(); //Execute purge query


        

        private void Button_Click_2(object sender, RoutedEventArgs e)
        
            

                string query = "select * from student";
                SqlCommand cmd = new SqlCommand(query, con);
                con.Open();

                // create data adapter
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                // this will query your database and return the result to your datatable
                da.Fill(DataGridView);
                con.Close();
                da.Dispose();
            









        





    

任何帮助将不胜感激，谢谢

【参考方案1】：

只需用您的表格填写DataTable 并将其绑定到GridView.DataContext。

像这样：

首先在 XAML 编辑器中添加DataGrid <DataGrid Name="customDataGrid" ItemsSource="Binding">

然后是后面的代码：

namespace WpfApplication4

        /// <summary>
        /// Interaction logic for MainWindow.xaml
        /// </summary>
        public partial class MainWindow : Window
        
            string connectionString = @"Data Source=(LocalDB)\v11.0;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True";

            public MainWindow()
            
                InitializeComponent();
            

            private void button1_Click(object sender, EventArgs e)
            
                DataTable table = null;
                string query = "select * from student";
                try
                
                    using (SqlConnection connection = new SqlConnection(this.connectionString))
                    
                        connection.Open();
                        using (SqlDataAdapter adapter = new SqlDataAdapter(query, connection))
                        
                            table = new DataTable();
                            adapter.Fill(table);
                        
                    
                
                catch (Exception ex)
                
                    //handle caught exception
                

                if (table != null)
                
                    customDataGrid.DataContext = table.DefaultView;
                
            
        

绑定部分：customDataGrid.DataContext = table.DefaultView;

【讨论】：

您好 SeM，感谢您的快速回复。它给了我一个错误错误 1 ​​找不到类型或命名空间名称“DataTable”（您是否缺少 using 指令或程序集引用？） h:\visual studio 2013\Projects\WpfApplication4\WpfApplication4\MainWindow.xaml.cs 138 13 WpfApplication4

另外，错误 3“System.Windows.Controls.DataGrid”不包含“DataSource”的定义，并且没有接受“System.Windows.Controls”类型的第一个参数的扩展方法“DataSource”。可以找到 DataGrid'（您是否缺少 using 指令或程序集引用？） h:\visual studio 2013\Projects\WpfApplication4\WpfApplication4\MainWindow.xaml.cs 159 31 WpfApplication4

第一个错误：添加引用using System.Data;

第二个：你把你的dataGridView1投成DataGrid，但是你需要投成DataGridView

您好，第一个效果很好，当我尝试从工具箱中获取 DataGridView 时，它只是被一个被阻止的符号遮住了？不会让我拖放。再次感谢您的所有帮助

【参考方案2】：

试试这个....

    private void Button_Click_2(object sender, EventArgs e)
    
        string query = "select * from student";
        SqlCommand cmd = new SqlCommand(query, con);
        con.Open();

        DataTable dt = new DataTable();

        // create data adapter
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        // this will query your database and return the result to your datatable
        da.Fill(dt);
        con.Close();
        da.Dispose();


        dataGridView1.DataSource = dt;
    

【参考方案3】：

        mysqlCommand command = conn.CreateCommand();
        command.CommandText = "Select * from student";
        try
        
            con.Open();

            MySqlDataAdapter sda = new MySqlDataAdapter();
            sda.SelectCommand = command;
            DataTable dbdataset = new DataTable();
            sda.Fill(dbdataset);
            BindingSource bSource = new BindingSource();

            bSource.DataSource = dbdataset;
            dataGridView1.DataSource = bSource;
            sda.Update(dbdataset);

        
        catch (Exception ex)
        
            Console.WriteLine(ex.Message);
        
        con.Close();

试试这个