//设有一个DataSet ds中有三个DataTable,分别是dt1,dt2,dt3,可以用下面的方法将dt1,dt2中的行拷到dt3中去:dt3.Clear();
////////////////////////////////////////////////////////
//下面是第一种方法
foreach(DataRow dr in dt1.Rows)
dt3.ImportRow(dr);
foreach(DataRow dr in dt2.Rows)
dt3.ImportRow(dr);
//第二种方法,可以有选择的拷贝
DataRow[] copyRows1 = dt1.Select();foreach (DataRow copyRow in copyRows1)
dt3.ImportRow(copyRow);DataRow[] copyRows2 = dt2.Select("ID='1'");foreach (DataRow copyRow in copyRows2)
dt3.ImportRow(copyRow);
////////////////////////////////////////////////////////////////////
this.dataGrid1.SetDataBinding(ds, null);
////////////////////////////////////////////////////////
//下面是第一种方法
foreach(DataRow dr in dt1.Rows)
dt3.ImportRow(dr);
foreach(DataRow dr in dt2.Rows)
dt3.ImportRow(dr);
//第二种方法,可以有选择的拷贝
DataRow[] copyRows1 = dt1.Select();foreach (DataRow copyRow in copyRows1)
dt3.ImportRow(copyRow);DataRow[] copyRows2 = dt2.Select("ID='1'");foreach (DataRow copyRow in copyRows2)
dt3.ImportRow(copyRow);
////////////////////////////////////////////////////////////////////
this.dataGrid1.SetDataBinding(ds, null);
DataSet custDS = new DataSet("CustomerOrders");//创建一个DataTable "Orders"
DataTable ordersTable = custDS.Tables.Add("Orders");
//创建另一个DataTable "Users"
custDS.Tables.Add("Users");//向"Orders" DataTable添加三个DataColumn
DataColumn pkCol = ordersTable["Orders"].Columns.Add("OrderID", typeof(Int32));
ordersTable["Orders"].Columns.Add("OrderQuantity", typeof(Int32));
ordersTable["Orders"].Columns.Add("CompanyName", typeof(string));//设置列名为"OrderID"的列为主键列
ordersTable["Orders"].PrimaryKey = new DataColumn[] {pkCol};//创建"Orders" DataTable的四个DataRow
for(int i = 0; i <= 4; i ++)
{
myDataRow = ordersTable["Orders"].NewRow();
myDataRow["OrderID"] = i;
myDataRow["OrderQuantity"] = i;
myDataRow["CompanyName"] = "Company" + i ;
ordersTable["Orders"].Rows.Add(myDataRow);
}//创建两个DataTable的约束关系
DataColumn parentColumn = myDataSet.Tables["Orders"].Columns["OrderID"];
DataColumn childColumn = myDataSet.Tables["Users"].Columns["UserID"]; //假设Users这个DataTable有一"UserID" DataColumn
ordersTable["Users"].ParentRelations.Add(new DataRelation("RelationName", parentColumn, childColumn));//将创建的DataSet与已创建控件dataGrid1数据绑定("Orders" DataTable作为第一个表)
dataGrid1.SetDataBinding(custDS, "Orders");
//把多个表合起来的SQL语句
string querystr="select * from (select * from table1 union all * from table2) t1t2";
//多个表合起来后的表名
string tablename="t1t2";
SqlDataAdapter thisAdapter = new SqlDataAdapter(querystr,ClassSQL.SqlConnection);
DataSet ds=new DataSet();
thisAdapter.Fill(ds,tablename);
DataTable dt=ds.Tables[tablename]; //把多个表合起来的结果集
ds.Merge(olderDs.Tables[0]);
DataTable dt = olderDs.Tables[1].Copy();
dt.TableName = ds.Tables[0].TableName;
ds.Merge(dt);
http://blog.csdn.net/zhzuo/archive/2004/08/06/67037.aspx
http://blog.aspcool.com/jiezhi/archive/2005/01/05/1637.html