Asp. NET Encapsulation class: Linked database

The connection database is encapsulated into classes, reducing code redundancy and enhancing code readability.

1. Construction of Class

Using System;
Using System.Collections.Generic;
Using System.Linq;
Using System.Web;
Using System.Data.SqlClient;

Using System.Data;
        Namespace Test {public class Dbsql {public SqlConnection conn = null;
        Public SqlDataAdapter da = null;
        Public SqlCommand com = null; Public Dbsql () {//string connstr = "server=.;D
            Atabase=library;uid=sa;pwd=123 ";
            conn = new SqlConnection (CONNSTR);
            com = new SqlCommand (); Com.

            Connection = conn; String connstr = "server=.;D
            Atabase=library;uid=sa;pwd=123 ";
            conn = new SqlConnection (CONNSTR);
            com = new SqlCommand (); Com.
            Connection = conn;
        da = new SqlDataAdapter ("", conn);
        ///<summary>///Returns the query result as a DataTable based on the query statement, and the return value is meaningless if the various update statements are executed. </summary>///<param name= "Selectsql" ></param>///<returns> Query Results </returns> Public DataTable Filldt (string selectsql) {//com.
            CommandType = CommandType.Text; Com.
            CommandText = "SELECT * from student";
            da = new SqlDataAdapter (COM);
            DataTable dt = new DataTable (); Da.
            Fill (DT);

            return DT;
            DataTable dt = new DataTable (); Da.
            SelectCommand.CommandText = Selectsql; Da.
            Fill (DT);
        return DT; ///<summary>///Execute various SQL statements///</summary>///<param name= "SQL" >true
        Indicates execution success, false indicates execution failure </param>///<returns></returns> public bool Execsql (string Sql)
            {bool R = false; Conn.
            Open (); Com.
            Connection = conn; Com.
            CommandType = CommandType.Text; Com.
            CommandText = SQL; Com.
            ExecuteNonQuery (); Conn.
            Close ();
            R = True;
      return R;  }
    }
} 

2. Class is used

Dbsql db = new Dbsql ();                        The instantiated DataTable of the class
dt = new DataTable ();
String strSQL = "INSERT into student (Sno,sname,ssex,sage) VALUES (' 3 ', ' Wang Peng ', ' Men ',)";
Db. Execsql (strSQL);                           Invokes the Execsql () method of the class, which implements the defined strSQL statement
dt = db. Filldt ("SELECT * from student");      Invoke the Filldt () method of the class to implement a query to the database this
. Gridview1.datasource = DT;
This. Gridview1.databind ();