使用DataGridView，DataTable和DataAdapter的CRUD操作-无法向DataGridView添加新行 [英] CRUD Operations using DataGridView, DataTable and DataAdapter - Cannot add new row to DataGridView

问题描述

我正在尝试从C＃接口网格视图向源表中插入新记录...。
但是，当我使用如下所示的buttonclick代码检索记录时...我正在gridview中获取记录但没有插入新记录的选项（附有屏幕截图）。在这里，我可以从网格视图更新reocrds。

I'm trying to insert new records into the source table from the C# interface grid view.... But when I retrieve the records with the buttonclick code shown below... Im getting records in the gridview but no option for inserting new records(screen shot attached).. where as i can update the reocrds from the grid view.

是否有任何选项或属性可以启用

Is there any option or property for enabling the insertion option in the gridview ?

Buttonclickcode：

Buttonclickcode :

private void RetrieveRules_button_Click(object sender, EventArgs e)
{
    this.dataGridView.DataSource = null;
    this.dataGridView.Rows.Clear();


    SqlCommand cmd1 = con.CreateCommand();
    cmd1.CommandType = CommandType.Text;
    cmd1.CommandText = @" Select TOP 1 * FROM " + schemaName + "[ERSBusinessLogic] ORDER BY ERSBusinessLogic_ID     DESC";
    con.Open();
    cmd1.ExecuteNonQuery();
    DataTable dt = new DataTable();
    SqlDataAdapter DA = new SqlDataAdapter(cmd1);
    DA.Fill(dt);
    dataGridView.DataSource = dt;
    con.Close();

}

谢谢

推荐答案

使用DataGridView，DataTable和DataAdapter的CRUD操作

要让用户使用 DataGridView 添加，删除或编辑行：

CRUD Operations using DataGridView, DataTable and DataAdapter

To let the user add, delete or edit rows with DataGridView:

1. 设置 AllowUserToAddRows 属性设置为true或在 DataGridView任务中，选中启用添加


2. 设置 AllowUserToDeleteRows 属性设置为true或在 DataGridView Tasks ，选中启用删除


3. 设置 ReadOnly 属性设置为false或在 DataGridView中任务，选中启用编辑

1. Set AllowUserToAddRows property to true or in DataGridView Tasks, check Enable Adding
2. Set AllowUserToDeleteRows property to true or in DataGridView Tasks, check Enable Deleting
3. Set ReadOnly property to false or in DataGridView Tasks, check Enable Editing

要让用户使用SqlDataAdapter保存更改，请执行以下操作：

To let the user save changes using a SqlDataAdapter:

1. 创建一个 SqlDataAdapter 使用select语句和连接字符串。


2. 您应该具有有效的 InsertCommand ， DeleteCom mand 和 UpdateCommand 用于您的数据适配器。使用创建有效的命令 SqlCommandBuilder 。


3. 将数据加载到 DataTable 使用数据适配器。


4. 将数据表设置为 DataGridView
的 DataSource b
5. 在需要使用 SqlDataAdapter.Update 通过将数据表传递给方法。

1. Create a SqlDataAdapter using a select statement and a connection string.
2. You should have valid InsertCommand, DeleteCommand and UpdateCommand for your data adapter. Create valid commands using a SqlCommandBuilder.
3. Load data to a DataTable using data adapter.
4. Set data table as DataSource of DataGridView
5. Save changes when you need using SqlDataAdapter.Update by passing data table to the method.

代码

DataTable table;
SqlDataAdapter adapter;
private void Form1_Load(object sender, EventArgs e)
{
    //Create adapter
    var connection = @"your connection string";
    var command = "SELECT * FROM Table1";
    adapter = new SqlDataAdapter(command, connection);

    //Create Insert, Update and Delete commands
    var builder = new SqlCommandBuilder(adapter);

    //Load data
    table = new DataTable();
    adapter.Fill(table);

    //Bind the grid to data
    this.dataGridView1.DataSource = table;

    //Enable add, delete and edit
    this.dataGridView1.AllowUserToAddRows = true;
    this.dataGridView1.AllowUserToDeleteRows = true;
    this.dataGridView1.ReadOnly = false;
}

private void saveButton_Click(object sender, EventArgs e)
{
    //Save Data
    adapter.Update(table);
}

private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
    adapter.Dispose();
}

注意

• 您不需要 ExecuteNonQuery 。您只需要一个连接字符串和一个命令文本。然后，您可以创建一个数据适配器。这样，您甚至无需管理打开和关闭连接，数据适配器即可管理它。


• 使用 SELECT TOP 1 * ，如果您添加数据并保存，则下次加载数据时将看不到更新，因为您仅加载一条记录。



• You don't need that ExecuteNonQuery. You only need a connection string and a command text. Then you can create a data adapter. Then you even don't need to manage opening and closing the connection, data adapter manages it.
• When you load data using SELECT TOP 1 *, if you add data and save, you can't see updates next time you load the data because you load only a single record.

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