Question

我有来自两个不同数据库的两个相同的DataTable（但是ID是唯一的！）。所以现在我想将这些数据合并为一个DataTable。我不知道该怎么做。

我尝试了以下内容：

DataTable one = new DataTable();
one = baza_win.pobierz_dane("SELECT...");
DataTable two = new DataTable();
two = baza_win2.pobierz_dane("SELECT...");
//DataTable sum = one + two;
DataTable sum = new DataTable();
sum.Clone(one);
sum.Merge(two,false);

但这不适用于sum.Clone(one);

有什么想法吗？

Answer 1

sum = one.Copy();
sum.Merge(two);

Answer 2

我认为你需要复制而不是克隆：

DataTable one = new DataTable();
one = baza_win.pobierz_dane("SELECT...");
DataTable two = new DataTable();
two = baza_win2.pobierz_dane("SELECT...");
//DataTable sum = one + two;
DataTable sum = new DataTable();
sum.Copy(one);
sum.Merge(two,false);

Answer 3

从链接中复制
http://msdn.microsoft.com/en-us/library/fk68ew7b.aspx

副本 how to join two datatable datas into one datatable to show in one gridview in asp.net

private static void DemonstrateMergeTable（） { DataTable table1 = new DataTable（“Items”）;

    // Add columns
    DataColumn column1 = new DataColumn("id", typeof(System.Int32));
    DataColumn column2 = new DataColumn("item", typeof(System.Int32));
    table1.Columns.Add(column1);
    table1.Columns.Add(column2);

    // Set the primary key column.
    table1.PrimaryKey = new DataColumn[] { column1 };

    // Add RowChanged event handler for the table.
    table1.RowChanged += 
        new System.Data.DataRowChangeEventHandler(Row_Changed);

    // Add some rows.
    DataRow row;
    for (int i = 0; i <= 3; i++)
    {
        row = table1.NewRow();
        row["id"] = i;
        row["item"] = i;
        table1.Rows.Add(row);
    }

    // Accept changes.
    table1.AcceptChanges();
    PrintValues(table1, "Original values");

    // Create a second DataTable identical to the first.
    DataTable table2 = table1.Clone();

    // Add three rows. Note that the id column can't be the  
    // same as existing rows in the original table.
    row = table2.NewRow();
    row["id"] = 14;
    row["item"] = 774;
    table2.Rows.Add(row);

    row = table2.NewRow();
    row["id"] = 12;
    row["item"] = 555;
    table2.Rows.Add(row);

    row = table2.NewRow();
    row["id"] = 13;
    row["item"] = 665;
    table2.Rows.Add(row);

    // Merge table2 into the table1.
    Console.WriteLine("Merging");
    table1.Merge(table2);
    PrintValues(table1, "Merged With table1");

}

private static void Row_Changed(object sender, 
    DataRowChangeEventArgs e)
{
    Console.WriteLine("Row changed {0}\t{1}", 
        e.Action, e.Row.ItemArray[0]);
}

private static void PrintValues(DataTable table, string label)
{
    // Display the values in the supplied DataTable:
    Console.WriteLine(label);
    foreach (DataRow row in table.Rows)
    {
        foreach (DataColumn col in table.Columns)
        {
            Console.Write("\t " + row[col].ToString());
        }
        Console.WriteLine();
    }
}

Answer 4

尝试以下方法... CLONE第一个表，因此它具有适当的结构，然后将两个合并到其中。

DataTable sum = one.Clone()
sum.Merge(two,false);

在C＃中将2个DataTables加入1

4 个答案: