合并两个DataTable

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++)