asp. net generic connection database instance code

  • 2020-06-19 10:05:20
  • OfStack

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<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<center>
<h2><font face=" Song typeface "> A generic code instance that accesses a database </font>
</h2>
</center>
<body>
    <form id="form1" runat="server">
    <div>
    <font face=" Song typeface ">
<p align="center">1. Please enter the appropriate database connection string </p>
<p align="center">
<asp:TextBox id="ConnStrTextBox" runat="server" Width="600"></asp:TextBox>
</p>
<p align="center">2. Please enter the corresponding SQL Query command statement </p>
<p align="center">
<asp:TextBox id="SqlTextTextBox" runat="server" Width="600"></asp:TextBox>
</p>
<p align="center">3. Select the type of database to connect to </p>
<p align="center">
    <asp:DropDownList ID="DBDropDownList" runat="server" Width="204px">
        <asp:ListItem Selected="True">Access</asp:ListItem>
        <asp:ListItem>SQLServer</asp:ListItem>
        <asp:ListItem>Oracle</asp:ListItem>
        <asp:ListItem>DB2</asp:ListItem>
    </asp:DropDownList>
</p>
<p align="center">

<asp:Button ID="Button1" runat="server" onclick="Button1_Click"  Text=" Universal database connection code testing " />

</p>
<p align="center">
<asp:Label id="lblMessage" runat="server" Font-Bold="True" ForeColor="Red"></asp:Label>
</p>
    </form>
</font>
</div>

asp net page


using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        // Generic database connection code, here to connect Access The database is the test example 
        if (!IsPostBack)
        {
           ConnStrTextBox.Text = "Provider=Microsoft.Jet.OLEDB.4.0; Data source=" + Server.MapPath("User.mdb");
           SqlTextTextBox.Text = "Select COUNT(*) From Info Where Name=' Small gu '";
            lblMessage.Text = "";
        }
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        // Define the database connection string 
        string MyConnectionString = this.ConnStrTextBox.Text;
        // Defines the query operation SQL statements 
        string MySQL = this.SqlTextTextBox.Text;
        // Define the type of database to connect to as Access
        string MyType = this.DBDropDownList.SelectedValue;
        System.Data.IDbConnection MyConnection = null;
        //  Based on the database type, create the corresponding  Connection  object 
        switch (MyType)
        {
            // The selected database type is" SQLServer ", create SqlConnection Class database connection object 
            case "SQLServer":
                MyConnection = new System.Data.SqlClient.SqlConnection(MyConnectionString);
                break;
            case "Oracle":
                MyConnection = new System.Data.OracleClient.OracleConnection(MyConnectionString);
                break;
            // The selected database type is" Access ", create OleDbConnection Class database connection object 
            case "Access":
                MyConnection = new System.Data.OleDb.OleDbConnection(MyConnectionString);
                break;
            // The selected database type is" DB2 ", create OleDbConnection Class database connection object 
            case "DB2":
                MyConnection = new System.Data.Odbc.OdbcConnection(MyConnectionString);
                break;
            default:
                MyConnection = new System.Data.OleDb.OleDbConnection(MyConnectionString);
                break;
        }
        Execute(MyConnection, MySQL);
    }
    public void Execute(System.Data.IDbConnection MyConnection, string strquery)
    {
        // use  CreateCommand()  Method to generate  Command  object 
        System.Data.IDbCommand MyCommand = MyConnection.CreateCommand();
        // Execution-Defined SQL The query 
        MyCommand.CommandText = strquery;
        try
        {
            // Open database connection 
            MyConnection.Open();
            // Define the result information for the query 
            String MyInfo = " Test connection successful! The total number of records meeting the query requirements is: " + MyCommand.ExecuteScalar().ToString() + " Article! ";
            // Output query result information 
            lblMessage.Text = MyInfo;
        }
        catch (Exception ex)
        {
            // Output error exception 
            Response.Write(ex.ToString());
        }
        finally
        {
            // Close the database connection 
            MyConnection.Close();
        }
    }
}

The core code of this program is


// The selected database type is" SQLServer ", create SqlConnection Class database connection object 
case "SQLServer":
           MyConnection = new System.Data.SqlClient.SqlConnection(MyConnectionString);
                break;
case "Oracle":
           MyConnection = new System.Data.OracleClient.OracleConnection(MyConnectionString);
                break;
            // The selected database type is" Access ", create OleDbConnection Class database connection object 
case "Access":
           MyConnection = new System.Data.OleDb.OleDbConnection(MyConnectionString);
                break;
            // The selected database type is" DB2 ", create OleDbConnection Class database connection object 
case "DB2":
           MyConnection = new System.Data.Odbc.OdbcConnection(MyConnectionString);
                break;
default:
            MyConnection = new System.Data.OleDb.OleDbConnection(MyConnectionString);
                break;

If you want another connection we can add one more connection code.


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