如何合并DataTable

两个结构一样的DataTable合并

NET 2.0 以上版本直接有 DataTable.Merge 方法：

http://msdn.microsoft.com/zh-cn/library/fk68ew7b.aspx

.NET Framework 类库
DataTable.Merge 方法


将指定的 DataTable 与当前的 DataTable 合并。


命名空间： System.Data
程序集： System.Data（在 System.Data.dll 中）
或者：
DataTable DataTable1 = new DataTable();   
DataTable DataTable2 = new DataTable();   
DataTable newDataTable = DataTable1.Clone();   
 
object[] obj = new object[newDataTable.Columns.Count];   
for (int i = 0; i < DataTable1.Rows.Count; i++)   
{   
    DataTable1.Rows[i].ItemArray.CopyTo(obj,0);   
    newDataTable.Rows.Add(obj);   
}   
for (int i = 0; i < DataTable2.Rows.Count; i++)   
{   
    DataTable2.Rows[i].ItemArray.CopyTo(obj,0);   
    newDataTable.Rows.Add(obj);   
}  
//或者  
DataTable DataTable1 = new DataTable();   
DataTable DataTable2 = new DataTable();   
 
object[] obj = new object[DataTable1 .Columns.Count];   
for (int i = 0; i < DataTable2.Rows.Count; i++)   
{   
    DataTable2.Rows[i].ItemArray.CopyTo(obj,0);   
    DataTable1.Rows.Add(obj);   
} 
DataTable DataTable1 = new DataTable();
DataTable DataTable2 = new DataTable();
DataTable newDataTable = DataTable1.Clone();

object[] obj = new object[newDataTable.Columns.Count];
for (int i = 0; i < DataTable1.Rows.Count; i++)
{
    DataTable1.Rows[i].ItemArray.CopyTo(obj,0);
    newDataTable.Rows.Add(obj);
}
for (int i = 0; i < DataTable2.Rows.Count; i++)
{
    DataTable2.Rows[i].ItemArray.CopyTo(obj,0);
    newDataTable.Rows.Add(obj);
}
//或者
DataTable DataTable1 = new DataTable();
DataTable DataTable2 = new DataTable();

object[] obj = new object[DataTable1 .Columns.Count];
for (int i = 0; i < DataTable2.Rows.Count; i++)
{
    DataTable2.Rows[i].ItemArray.CopyTo(obj,0);
    DataTable1.Rows.Add(obj);
}

两个结构不同的DataTable合并 

view plaincopy to clipboardprint?
/// <summary>   
/// 将两个列不同的DataTable合并成一个新的DataTable   
/// </summary>   
/// <param name="dt1">Table表1</param>   
/// <param name="dt2">Table表2</param>   
/// <param name="DTName">合并后新的表名</param>   
/// <returns></returns>  
 
private DataTable UniteDataTable( DataTable dt1 ,DataTable dt2 ,string DTName)   
{    
 DataTable dt3 = dt1.Clone();   
 for( int i = 0 ;i < dt2.Columns.Count ;i ++ )   
 {   
  dt3.Columns.Add( dt2.Columns[i].ColumnName ) ;   
 }   
 object[] obj = new object[dt3.Columns.Count];   
    
 for (int i = 0; i < dt1.Rows.Count; i++)   
 {   
  dt1.Rows[i].ItemArray.CopyTo(obj,0);   
  dt3.Rows.Add(obj);   
 }   
       
 if( dt1.Rows.Count >= dt2.Rows.Count )   
 {   
  for( int i = 0 ;i < dt2.Rows.Count ;i++ )   
  {   
   for( int j = 0 ;j < dt2.Columns.Count ;j ++ )   
   {   
    dt3.Rows[i][j+dt1.Columns.Count] = dt2.Rows[i][j].ToString() ;   
   }   
  }   
 }   
 else   
 {   
  DataRow dr3 ;   
  for( int i = 0 ;i < dt2.Rows.Count - dt1.Rows.Count ;i ++ )   
  {   
   dr3 = dt3.NewRow() ;   
   dt3.Rows.Add( dr3 ) ;   
  }   
  for( int i = 0 ;i < dt2.Rows.Count ;i++ )   
  {   
   for( int j = 0 ;j < dt2.Columns.Count ;j ++ )   
   {   
    dt3.Rows[i][j+dt1.Columns.Count] = dt2.Rows[i][j].ToString() ;   
   }   
  }   
 }   
 dt3.TableName = DTName ;   
 return dt3 ;   
}