Simultaneous query of two database tables in asp.net

A question recently asked was how to make a federated query of tables in two databases.

Then I used the stupidest method to achieve it. Want to see a friend can give a good solution, with only one connection string. It's best to give a detailed tutorial.

First there are two databases with two tables in each database.

The data in the table is also very simple, is the Student table and professional table, with professional Number association.

The following data is tied to the DataGridView in Winfrom, showing the student's number, name, age, and major. The effect is as follows:

Because of the operation of the data I used the LINQ to DataSet so the project's. NET version is more than 3.5.

The following is the code that binds the data:

The code is as follows

Copy Code

Using System; Using System.Collections.Generic; Using System.ComponentModel; Using System.Data; Using System.Drawing; Using System.Text; Using System.Windows.Forms; Using System.Data.SqlClient; Using System.Linq; Namespace Linktwodata { public partial class Form1:form { Public Form1 () { InitializeComponent (); } String strcon1 = @ "Data source=feng-pcsqlexpress;initial catalog=test1; User Id=sa; Password=sa2008 "; String strcon2 = @ "Data source=feng-pcsqlexpress;initial catalog=test2; User Id=sa; Password=sa2008 "; private void Form1_Load (object sender, EventArgs e) { SqlDataAdapter sda1 = new SqlDataAdapter ("select * from STU1", strcon1); SqlDataAdapter sda2 = new SqlDataAdapter ("select * from STU1", strcon2); DataSet ds = new DataSet (); Sda1. Fill (ds, "stu1"); Sda2. Fill (ds, "STU2"); var query = from Stu in DS. tables["STU1"]. AsEnumerable () From SC in DS. tables["STU2"]. AsEnumerable () Where Stu. Field<int> ("sc") = = SC. Field<int> ("SC") Select New { Sno = Stu. Field<int> ("Sno", DataRowVersion.Original), Sname=stu. Field<string> ("Sname", DataRowVersion.Original), Sage = stu. Field<int> ("Sage", datarowversion.original), Scname = SC. Field<string> ("Scname", DataRowVersion.Original) }; DataTable dt = new DataTable (); Dt. Columns.Add ("Sno", typeof (int)); Dt. Columns.Add ("Sname", typeof (String)); Dt. Columns.Add ("Sage", typeof (String)); Dt. Columns.Add ("Scname", typeof (String)); foreach (var item in query) { DataRow newrow = dt. NewRow (); newrow["sno"] = Item.sno; newrow["sname"] = Item.sname; newrow["Sage"] = item.sage; newrow["scname"] = Item.scname; Dt. Rows.Add (NewRow); } Datagridview1.datasource = dt. DefaultView; } } }