Question

我想在数据集填充后选择数据集中的特定列（例如列等级）并将值放入列表中

string excelFile = @"C:\Scores.xlsx";
if (File.Exists(excelFile))
{
    string connString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source="+excelFile+";Extended Properties=Excel 12.0;";
    var dataAdapter = new OleDbDataAdapter();
    var objConn = new OleDbConnection(connString);

    //SELECT [Name],[Grade],[Location] ect...
    const string query = "SELECT * FROM [TeamScores$]"; 
    var objCmd = new OleDbCommand(query, objConn);

    var table = new DataSet();
    dataAdapter.SelectCommand = objCmd;
    dataAdapter.Fill(table);               

    //I would like to filter the DataSet to select only [Name] and populate the values into a List<string>

    dataGridView1.DataSource = table.Tables[0]; //Will show all results                

}

Answer 1

您的变量命名让您感到困惑。

var table = new DataSet();  // not good at all

DataSet不是表。 DataSet 包含 DataTables。

尝试：

DataSet ScoresDataSet = new DataSet();

然后你可以使用表格上的Select方法（类似......）：

DataTable ScoresTable = ScoresDataSet.Tables[0]; 

dataGridView1.DataSource = ScoresTable.Select("Your criteria");

Answer 2

我现在已经解决了我可以改变的问题＆＃34;等级＆＃34;我希望列到哪一列，它会显示相关的值。

DataTable scoresTable = ScoresDataSet.Tables[0];                
var result = scoresTable.AsEnumerable()
    .Select(r => r.Field<string>("Grade")).Where(r => r != null);

var listOfGrades = result.ToList();

Answer 3

您需要调整此行：

dataGridView1.DataSource = table.Tables[0]; //Will show all results

例如这一个：

dataGridView1.DataSource = table.Tables[0].Select("yourField=5")); // you filter the datarows where yourField is 5.

或

dataGridView1.DataSource = table.Tables[0].Select("yourField>5 and yourField<21")); // is another example

Answer 4

希望这可以帮到你：

System.Data.DataSet dsTemp2 = new System.Data.DataSet();


if (dsTemp2.Tables[0].Rows.Count <= 0)
    MessageBox.Show("Records not found");
else
{
    foreach (DataRow dRow in dsTemp2.Tables[0].Rows)
    {
        yourtextbox1.Text = dsTemp2.Tables[0].Rows[0][4].ToString();
        yourtextbox2.Text = dsTemp2.Tables[0].Rows[0][5].ToString();
        yourtextbox3.Text = dsTemp2.Tables[0].Rows[0][7].ToString();
    }
}

数据集选择列

4 个答案: