合并两个DataTable

方法1:

SqlConnection myConnection=new SqlConnection("server=localhost;uid=sa;pwd=;database=wjoa");
            string sql1="select * from ResourseManage_T";
            SqlDataAdapter adapterA=new SqlDataAdapter(sql1,myConnection);
            DataSet ds=new DataSet();
            adapterA.Fill(ds,"a");
            string sql2="select * from UserLogin_t";
                
            if(myConnection.State != ConnectionState.Closed)
            myConnection.Close();
            adapterA=new SqlDataAdapter(sql2, myConnection);
            adapterA.Fill(ds,"b");
            DataTable dtParent=ds.Tables["a"];
            DataTable dtChild=ds.Tables["b"];
            DataRow dr;
            for(int i=0;i<dtChild.Rows.Count;i++)
            {     
                dr=dtParent.NewRow();
                for(int j=0;j<dtParent.Columns.Count;j++)
                {
                    dr[j]=dtChild.Rows[i][j];
                }
                dtParent.Rows.Add(dr);
            }
            this.DataGrid1.DataSource=ds.Tables["a"].DefaultView;
            this.DataGrid1.DataBind();

 

方法2:

 

//两个结构一样的DT合并
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);
}
//两个结构不同的DT合并
/// <summary>
  /// 将两个列不同的DataTable合并成一个新的DataTable
  /// </summary>
  /// <param name="dt1">表1</param>
  /// <param name="dt2">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 ; //设置DT的名字
   return dt3 ;
  }