Getting Records from a DataBase Using the DataReader Class in FSharp

Introduction:

The DataReader class is used in connected architectures in .NET. It is used for getting records from a Back-end (DataBase) to a Front-end interface control. Now we will create a F# application which will show records from a DataBase in a ListBox. At first we will create a DataBase and insert some records into the DataBase table.

Creating DataBase: We create a DataBase for binding. Here in my example, the DataBase name is student_record, table name is student and Columns are Roll_No and Name. I am using SQL server. I have written code for creating this database. Look at the below SQL statements.

create database student_record

use student_record

create table student
( Roll_No int primary key,
Name varchar(20) )

insert into student values(1,'Alok Pandey')

After creating DataBase and table, we start to develop F# application that will show record from DataBase using DataReader class. We follow the following steps for this.

Step 1: We open Visual Studio and create a F# application.

datareader in f#

The application page will look like the below figure.

databinding in f#

Step 2: We go to Solution Explorer and Right Click on References.

Step 3: Click on Add References. Then a pop-up window with caption Add Reference will open as below figure.

databinding in f#

Step 4:Click at .NET on Add Reference window and select System.Windows.Forms, System.Drawing and System.Data with holding down Ctrl key and Click on Ok.

databinding in f#

Step 5: Then write the below F# code in the Program.fs file.

//Adding NameSpace
open System
open System.Windows.Forms
open System.Data.SqlClient
open System.Drawing
//Connection String
let constring = @"Data Source=Server_Name;Initial Catalog=student_record;Integrated Security=True"
//Creating Window Form
let frm = new Form()
//Creating ListBox
let list = new ListBox()
//Adding Control(ListBox)
frm.Controls.Add(list)
//Creating SqlConnection
let con = new SqlConnection(constring)
//Open connection
con.Open()
//Creating SqlCommand
let com = new SqlCommand()
//Command Text
com.CommandText <- "select name from student"
//Making Connection
com.Connection <- con
//ExecuteReaader
let dr = com.ExecuteReader()
//Fetching Record into ListBox from DataBase
if dr.Read() then
for i = 0 to (dr.FieldCount - 1) do
list.Items.Add(dr.Item(i))|>ignore
//Closing DataReader
dr.Close()
//Closing Connection
con.Close()
Application.Run(frm)

The code window looks like the below figure.

databinding in f#

Step 6: Run the application by pressing the Ctrl+F5 keys.

databinding in f#