Ado .Net

ADO.NET Tutorial with Inline SQL Examples

1. Introduction to ADO.NET

ADO.NET is a data access technology in .NET that allows communication with relational databases using managed providers such as SqlClient and OleDb.

2. SqlConnection and SqlDataReader Example (C#)

This example demonstrates reading data using inline SQL:

<script runat="server">
using System.Data.SqlClient;

SqlConnection cnn;
SqlCommand cmd;
SqlDataReader dr;

protected void Page_Load(object sender, EventArgs e)
{
    cnn = new SqlConnection("Integrated Security=SSPI;Initial Catalog=Northwind");
    cnn.Open();
    cmd = new SqlCommand("SELECT * FROM Categories", cnn);
    dr = cmd.ExecuteReader();
    while (dr.Read())
    {
        lstCategories.Items.Add(dr["CategoryName"].ToString());
    }
}
</script>

VB.NET Equivalent:

<script runat="server">
Imports System.Data.SqlClient

Dim cnn As SqlConnection
Dim cmd As SqlCommand
Dim dr As SqlDataReader

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    cnn = New SqlConnection("Integrated Security=SSPI;Initial Catalog=Northwind")
    cnn.Open()
    cmd = New SqlCommand("SELECT * FROM Categories", cnn)
    dr = cmd.ExecuteReader()
    While dr.Read()
        lstCategories.Items.Add(dr("CategoryName"))
    End While
End Sub
</script>

3. Inserting Records using Inline SQL

<script runat="server">
SqlCommand cmd;

protected void btnInsert_Click(object sender, EventArgs e)
{
    cmd = new SqlCommand("INSERT INTO Categories VALUES ('Condiments')", cnn);
    cmd.ExecuteNonQuery();
    MessageBox.Show("Record saved");
}
</script>

4. Inserting TextBox Values

<script runat="server">
protected void btnInsert_Click(object sender, EventArgs e)
{
    string strSql = "INSERT INTO Categories VALUES ('" + txtCategoryName.Text + "')";
    cmd = new SqlCommand(strSql, cnn);
    cmd.ExecuteNonQuery();
    MessageBox.Show("Record saved");
    txtCategoryName.Text = "";
    txtCategoryName.Focus();
}
</script>

5. Using DataAdapter and DataSet

<script runat="server">
using System.Data.SqlClient;

SqlConnection cnn;
SqlDataAdapter da;
DataSet ds = new DataSet();

protected void Page_Load(object sender, EventArgs e)
{
    cnn = new SqlConnection("Integrated Security=SSPI;Initial Catalog=Northwind");
    da = new SqlDataAdapter("SELECT * FROM Categories", cnn);
    da.Fill(ds, "Categories");
    dataGridView1.DataSource = ds.Tables["Categories"];
}
</script>

6. Working with Multiple DataTables

<script runat="server">
SqlDataAdapter da;
DataSet ds = new DataSet();

protected void Page_Load(object sender, EventArgs e)
{
    cnn = new SqlConnection("Integrated Security=SSPI;Initial Catalog=Northwind");

    da = new SqlDataAdapter("SELECT CategoryId, CategoryName FROM Categories", cnn);
    da.Fill(ds, "Cat");

    da = new SqlDataAdapter("SELECT ProductId, ProductName FROM Products", cnn);
    da.Fill(ds, "Prod");

    dataGrid1.DataSource = ds;
}
</script>

7. Creating AutoIncrement Column in DataTable

<script runat="server">
DataTable dt = new DataTable("Purchase");
DataColumn dc;
DataRow dr;

protected void Page_Load(object sender, EventArgs e)
{
    dc = new DataColumn("ProductID", typeof(int));
    dc.AutoIncrement = true;
    dc.AutoIncrementSeed = 100;
    dc.AutoIncrementStep = 1;
    dt.Columns.Add(dc);

    dc = new DataColumn("ProductName");
    dt.Columns.Add(dc);

    dc = new DataColumn("Price");
    dt.Columns.Add(dc);

    dr = dt.NewRow();
    dr["ProductName"] = "Microsoft Mouse";
    dr["Price"] = 400;
    dt.Rows.Add(dr);

    dgPurchase.DataSource = dt;
}
</script>

8. ComboBox DisplayMember Binding

<script runat="server">
SqlConnection cnn;
SqlDataAdapter da;
DataSet ds = new DataSet();

protected void Page_Load(object sender, EventArgs e)
{
    cnn = new SqlConnection("Integrated Security=SSPI;Initial Catalog=Northwind");
    da = new SqlDataAdapter("SELECT CategoryId, CategoryName FROM Categories", cnn);
    da.Fill(ds, "Cat");

    cboCategories.DataSource = ds.Tables["Cat"];
    cboCategories.DisplayMember = "CategoryName";
}
</script>

React Native

React Native is a technology from Facebook to create native Android and iPhone applications. It uses the familiar JavaScript language and JSX syntax.

The easiest way to get started with React Native is to install Expo app in you mobile, going to https://snack.expo.io site and start coding. Setting up a development environment for React Native is a bit involved. We will take it up later.




>npm i -g create-react-native-app

>npm run android

Node JS

Node is a JavaScript based Web Framework. Node's Non-blocking architecture makes it a very popular framework. V8 is the Virtual Machine of Node.


Node REPL
Once Node is installed, Node REPL can be invoked by typing node in the command prompt.

Typing tab tab in the prompt  displays  all Global command.

If you type a module name followed by tab tab it will display all the options pertaining to it.

Creating Http Server

const http = require('http');

const server = http.createServer((req, res) => {
  res.end('Hello World\n');
});

server.listen(4242, () => {
  console.log('Server is running...');
});

setTimeOut

setTimeout(
  () => {
    console.log('Hello after 4 seconds');
  },
  4 * 1000
);

Functions and Arguments

const consulting = who => {
  console.log(who + ' consulting');
};

setTimeout(consulting, 2 * 1000, 'Shalvin');

Express JS

Hello Express

var express = require('express');

var app = express();

app.get('/', function (req, res) {
    res.send('Hello from Library app');
})

app.listen(3000, function () {
    console.log('listening ');
})

sendFile

In the previous example we just displayed some text. Now we are going to add an html file into the views folder and name it index.html.

var express = require('express');
var path = require('path');

var app = express();

app.get('/', function(req, res){
    res.sendFile(path.join(__dirname, 'views', 'index.html'));
})

app.listen(3000, function(){
    console.log('listening');
})

React State Collection of Objects

import React, { Component } from 'react';
import Person from './Person/Person';



class App extends Component {
  state = {
    person: [{name:'Shalvin P D', location: 'Kakkanad'},
    {name:'Shibin', location: 'Trivandrum'}
  ]
  }

  render() {
    return (
      <div>
        <h2>State eg</h2>

        
        <Person name = {this.state.person[0].name} 
        location = {this.state.person[0].location}></Person>

      <Person name = {this.state.person[1].name} 
        location = {this.state.person[1].location}></Person>
      </div>
    );
  }
}

export default App;

Angular Routing

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';

import { AppComponent } from './app.component';
import { ContactComponent } from './contact/contact.component';
import { DashboardComponent } from './dashboard/dashboard.component';
import {RouterModule, Routes} from '@angular/router';

@NgModule({
  declarations: [
    AppComponent,
    ContactComponent,
    DashboardComponent
  ],
  
   
  imports: [
    BrowserModule,
     RouterModule.forRoot([
       {path:'contact', component :ContactComponent},
       {path:'dashboard', component :DashboardComponent}
       ])
  ],
  providers: [],
  bootstrap: [AppComponent]
  
})
export class AppModule { }

app.component.ts

 <h1>{{title}}</h1>
 <a routerLink="/dashboard">Dashboard</a>
 <a routerLink="/contact">Contact</a>
   
  <router-outlet></router-outlet>

MVC 5 Code First with Existing Database - Training Management Project

Table Script

USE [TrainingManagement]

GO
CREATE TABLE [dbo].[Attendance](
    [AttendanceId] [int] IDENTITY(1,1) NOT NULL,
    [BatchId] [int] NULL,
    [FacultyId] [int] NULL,
    [Date] [date] NULL,
    [HoursTaken] [int] NULL,
    [CoveredModules] [varchar](200) NULL,
    [Remarks] [varchar](200) NULL,
 CONSTRAINT [PK_BatchSchedule] PRIMARY KEY CLUSTERED 
(
    [AttendanceId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF
GO
/****** Object:  Table [dbo].[Batch]    Script Date: 5/29/2017 8:23:41 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Batch](
    [BatchId] [int] IDENTITY(1,1) NOT NULL,
    [CourseId] [int] NULL,
    [BatchName] [varchar](40) NULL,
    [StartDate] [date] NULL,
    [TentativeEndDate] [date] NULL,
    [BatchTiming] [varchar](100) NULL,
    [Hours] [int] NULL,
    [HoursTaken] [int] NULL,
    [Fees] [int] NULL,
    [FeesPaid] [int] NULL,
    [Status] [varchar](15) NULL,
    [Remarks] [varchar](300) NULL,
 CONSTRAINT [PK__Batch__5D55CE58980177C0] PRIMARY KEY CLUSTERED 
(
    [BatchId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF
GO
/****** Object:  Table [dbo].[Course]    Script Date: 5/29/2017 8:23:41 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Course](
    [CourseId] [int] IDENTITY(1,1) NOT NULL,
    [CourseName] [varchar](40) NULL,
    [DurationInHours] [int] NULL,
    [Fees] [int] NULL,
    [Remarks] [varchar](200) NULL,
PRIMARY KEY CLUSTERED 
(
    [CourseId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF
GO
/****** Object:  Table [dbo].[Faculty]    Script Date: 5/29/2017 8:23:41 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Faculty](
    [FacultyId] [int] IDENTITY(1,1) NOT NULL,
    [FacultyName] [varchar](40) NULL,
    [Specialization] [varchar](40) NULL,
    [Phone] [varchar](15) NULL,
    [Email] [varchar](40) NULL,
PRIMARY KEY CLUSTERED 
(
    [FacultyId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF
GO
/****** Object:  Table [dbo].[Fees]    Script Date: 5/29/2017 8:23:41 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Fees](
    [FeesId] [int] IDENTITY(1,1) NOT NULL,
    [BatchId] [int] NULL,
    [Date] [date] NULL,
    [Amout] [numeric](8, 2) NULL,
    [Description] [varchar](200) NULL,
 CONSTRAINT [PK_Fees] PRIMARY KEY CLUSTERED 
(
    [FeesId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF
GO
/****** Object:  Table [dbo].[Student]    Script Date: 5/29/2017 8:23:41 AM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Student](
    [StudentId] [int] IDENTITY(1,1) NOT NULL,
    [BatchId] [int] NULL,
    [StudentName] [varchar](50) NULL,
    [YearsOfExperience] [int] NULL,
    [TechnologiesKnown] [varchar](100) NULL,
    [Location] [varchar](50) NULL,
    [Phone] [varchar](50) NULL,
    [Email] [varchar](200) NULL,
 CONSTRAINT [PK_Student] PRIMARY KEY CLUSTERED 
(
    [StudentId] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]

GO
SET ANSI_PADDING OFF
GO
SET IDENTITY_INSERT [dbo].[Attendance] ON 

INSERT [dbo].[Attendance] ([AttendanceId], [BatchId], [FacultyId], [Date], [HoursTaken], [CoveredModules], [Remarks]) VALUES (1, 1, 2, NULL, 2, N'JQuery Ajax', NULL)
INSERT [dbo].[Attendance] ([AttendanceId], [BatchId], [FacultyId], [Date], [HoursTaken], [CoveredModules], [Remarks]) VALUES (2, 1, 1, NULL, 5, N'Angular Service', N'Given enough assignments for two weeks.')
INSERT [dbo].[Attendance] ([AttendanceId], [BatchId], [FacultyId], [Date], [HoursTaken], [CoveredModules], [Remarks]) VALUES (3, 1, 1, NULL, 5, NULL, NULL)
INSERT [dbo].[Attendance] ([AttendanceId], [BatchId], [FacultyId], [Date], [HoursTaken], [CoveredModules], [Remarks]) VALUES (4, 2, 1, NULL, 3, NULL, NULL)
INSERT [dbo].[Attendance] ([AttendanceId], [BatchId], [FacultyId], [Date], [HoursTaken], [CoveredModules], [Remarks]) VALUES (5, 2, 1, NULL, 3, NULL, NULL)
INSERT [dbo].[Attendance] ([AttendanceId], [BatchId], [FacultyId], [Date], [HoursTaken], [CoveredModules], [Remarks]) VALUES (6, 2, 1, CAST(0xB03C0B00 AS Date), 5, N'Entity Framework', N'Entity Framework Database First')
INSERT [dbo].[Attendance] ([AttendanceId], [BatchId], [FacultyId], [Date], [HoursTaken], [CoveredModules], [Remarks]) VALUES (7, 5, 1, NULL, 5, NULL, NULL)
SET IDENTITY_INSERT [dbo].[Attendance] OFF
SET IDENTITY_INSERT [dbo].[Batch] ON 

INSERT [dbo].[Batch] ([BatchId], [CourseId], [BatchName], [StartDate], [TentativeEndDate], [BatchTiming], [Hours], [HoursTaken], [Fees], [FeesPaid], [Status], [Remarks]) VALUES (1, 2, N'Gemini Softwares ', NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL)
INSERT [dbo].[Batch] ([BatchId], [CourseId], [BatchName], [StartDate], [TentativeEndDate], [BatchTiming], [Hours], [HoursTaken], [Fees], [FeesPaid], [Status], [Remarks]) VALUES (2, 2, N'.Net Morning', CAST(0x843C0B00 AS Date), CAST(0x46BD0B00 AS Date), N'Mornings 6.30 - 8.30 am and Sundays', 60, 38, 15000, 4, N'Ongoing', N'Slow batch')
INSERT [dbo].[Batch] ([BatchId], [CourseId], [BatchName], [StartDate], [TentativeEndDate], [BatchTiming], [Hours], [HoursTaken], [Fees], [FeesPaid], [Status], [Remarks]) VALUES (3, 3, N'State Syllabus', NULL, NULL, NULL, 60, NULL, 6000, NULL, NULL, NULL)
INSERT [dbo].[Batch] ([BatchId], [CourseId], [BatchName], [StartDate], [TentativeEndDate], [BatchTiming], [Hours], [HoursTaken], [Fees], [FeesPaid], [Status], [Remarks]) VALUES (4, 2, N'Technobay ', CAST(0x6C3C0B00 AS Date), NULL, N'Sundays', 60, 30, 15000, 4000, N'Ongoing', NULL)
INSERT [dbo].[Batch] ([BatchId], [CourseId], [BatchName], [StartDate], [TentativeEndDate], [BatchTiming], [Hours], [HoursTaken], [Fees], [FeesPaid], [Status], [Remarks]) VALUES (5, 1, N'Palnar Transmedia', NULL, NULL, NULL, 60, 0, 70000, NULL, NULL, NULL)
SET IDENTITY_INSERT [dbo].[Batch] OFF
SET IDENTITY_INSERT [dbo].[Course] ON 

INSERT [dbo].[Course] ([CourseId], [CourseName], [DurationInHours], [Fees], [Remarks]) VALUES (1, N'Asp .Net MVC', 60, 10000, N'Asp  .Net MVC 5')
INSERT [dbo].[Course] ([CourseId], [CourseName], [DurationInHours], [Fees], [Remarks]) VALUES (2, N'Asp .Net MVC and Angular', 100, 15000, N'Asp .Net MVC 5, Angular and TypeScript')
INSERT [dbo].[Course] ([CourseId], [CourseName], [DurationInHours], [Fees], [Remarks]) VALUES (3, N'State Plus 2', 60, 60000, N'State Syllabus Plus 2')
INSERT [dbo].[Course] ([CourseId], [CourseName], [DurationInHours], [Fees], [Remarks]) VALUES (5, N'Asp .Net Core', 60, 10000, N'If the candidates already know asp .Net MVC, then only 40 hours is required')
INSERT [dbo].[Course] ([CourseId], [CourseName], [DurationInHours], [Fees], [Remarks]) VALUES (6, NULL, NULL, NULL, NULL)
SET IDENTITY_INSERT [dbo].[Course] OFF
SET IDENTITY_INSERT [dbo].[Faculty] ON 

INSERT [dbo].[Faculty] ([FacultyId], [FacultyName], [Specialization], [Phone], [Email]) VALUES (1, N'Shalvin', N'MVC, Angular, TypeScript, C#', N'974580051w', N'shalvin@gmail.com')
INSERT [dbo].[Faculty] ([FacultyId], [FacultyName], [Specialization], [Phone], [Email]) VALUES (2, N'Mahin', N'MVC, Angular, TypeScript, C#, JQuery', N'78787878787', N'mahinna@gmail.com')
SET IDENTITY_INSERT [dbo].[Faculty] OFF
SET IDENTITY_INSERT [dbo].[Fees] ON 

INSERT [dbo].[Fees] ([FeesId], [BatchId], [Date], [Amout], [Description]) VALUES (1, 1, CAST(0xDD3C0B00 AS Date), CAST(20000.00 AS Numeric(8, 2)), N'Fees paid')
SET IDENTITY_INSERT [dbo].[Fees] OFF
SET IDENTITY_INSERT [dbo].[Student] ON 

INSERT [dbo].[Student] ([StudentId], [BatchId], [StudentName], [YearsOfExperience], [TechnologiesKnown], [Location], [Phone], [Email]) VALUES (1, 2, N'arun', 3, N'asp.net,sql,html', N'alappuzha', N'8943781437', NULL)
SET IDENTITY_INSERT [dbo].[Student] OFF
ALTER TABLE [dbo].[Attendance]  WITH CHECK ADD  CONSTRAINT [FK_BatchSchedule_Batch] FOREIGN KEY([BatchId])
REFERENCES [dbo].[Batch] ([BatchId])
GO
ALTER TABLE [dbo].[Attendance] CHECK CONSTRAINT [FK_BatchSchedule_Batch]
GO
ALTER TABLE [dbo].[Attendance]  WITH CHECK ADD  CONSTRAINT [FK_BatchSchedule_Faculty] FOREIGN KEY([FacultyId])
REFERENCES [dbo].[Faculty] ([FacultyId])
GO
ALTER TABLE [dbo].[Attendance] CHECK CONSTRAINT [FK_BatchSchedule_Faculty]
GO
ALTER TABLE [dbo].[Batch]  WITH CHECK ADD  CONSTRAINT [FK_Batch_Course] FOREIGN KEY([CourseId])
REFERENCES [dbo].[Course] ([CourseId])
GO
ALTER TABLE [dbo].[Batch] CHECK CONSTRAINT [FK_Batch_Course]
GO
ALTER TABLE [dbo].[Fees]  WITH CHECK ADD  CONSTRAINT [FK_Fees_Batch] FOREIGN KEY([BatchId])
REFERENCES [dbo].[Batch] ([BatchId])
GO
ALTER TABLE [dbo].[Fees] CHECK CONSTRAINT [FK_Fees_Batch]
GO
ALTER TABLE [dbo].[Student]  WITH CHECK ADD  CONSTRAINT [FK_Student_Batch] FOREIGN KEY([BatchId])
REFERENCES [dbo].[Batch] ([BatchId])
GO
ALTER TABLE [dbo].[Student] CHECK CONSTRAINT [FK_Student_Batch]
GO

DbContext

namespace TrainingManagementExistingDBCodeFirstShalvin.Models
{
    using System.Data.Entity;

    public partial class TrainingManagementContext : DbContext
    {
        public Model1()
            : base("name=Model1")
        {
        }

        public virtual DbSet<Attendance> Attendances { get; set; }
        public virtual DbSet<Batch> Batches { get; set; }
        public virtual DbSet<Course> Courses { get; set; }
        public virtual DbSet<Faculty> Faculties { get; set; }
        public virtual DbSet<Fee> Fees { get; set; }
        public virtual DbSet<Student> Students { get; set; }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Attendance>()
                .Property(e => e.CoveredModules)
                .IsUnicode(false);

            modelBuilder.Entity<Attendance>()
                .Property(e => e.Remarks)
                .IsUnicode(false);

            modelBuilder.Entity<Batch>()
                .Property(e => e.BatchName)
                .IsUnicode(false);

            modelBuilder.Entity<Batch>()
                .Property(e => e.BatchTiming)
                .IsUnicode(false);

            modelBuilder.Entity<Batch>()
                .Property(e => e.Status)
                .IsUnicode(false);

            modelBuilder.Entity<Batch>()
                .Property(e => e.Remarks)
                .IsUnicode(false);

            modelBuilder.Entity<Course>()
                .Property(e => e.CourseName)
                .IsUnicode(false);

            modelBuilder.Entity<Course>()
                .Property(e => e.Remarks)
                .IsUnicode(false);

            modelBuilder.Entity<Faculty>()
                .Property(e => e.FacultyName)
                .IsUnicode(false);

            modelBuilder.Entity<Faculty>()
                .Property(e => e.Specialization)
                .IsUnicode(false);

            modelBuilder.Entity<Faculty>()
                .Property(e => e.Phone)
                .IsUnicode(false);

            modelBuilder.Entity<Faculty>()
                .Property(e => e.Email)
                .IsUnicode(false);

            modelBuilder.Entity<Fee>()
                .Property(e => e.Amout)
                .HasPrecision(8, 2);

            modelBuilder.Entity<Fee>()
                .Property(e => e.Description)
                .IsUnicode(false);

            modelBuilder.Entity<Student>()
                .Property(e => e.StudentName)
                .IsUnicode(false);

            modelBuilder.Entity<Student>()
                .Property(e => e.TechnologiesKnown)
                .IsUnicode(false);

            modelBuilder.Entity<Student>()
                .Property(e => e.Location)
                .IsUnicode(false);

            modelBuilder.Entity<Student>()
                .Property(e => e.Phone)
                .IsUnicode(false);

            modelBuilder.Entity<Student>()
                .Property(e => e.Email)
                .IsUnicode(false);
        }
    }
}

Course Model Class

namespace TrainingManagementExistingDBCodeFirstShalvin.Models
{
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;

    [Table("Course")]
    public partial class Course
    {
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
        public Course()
        {
            Batches = new HashSet<Batch>();
        }

        public int CourseId { get; set; }

        [StringLength(40, ErrorMessage ="Course name should not exceed 40 characters")]
        [Required(ErrorMessage = "Course is required")]
        [Display(Name = "Course")]
        public string CourseName { get; set; }

        [Display(Name ="Duration")]
        [RegularExpression("([0-9]+)", ErrorMessage ="Hours should be numeric")]
        public int? DurationInHours { get; set; }

        public int? Fees { get; set; }

        [StringLength(200)]
        public string Remarks { get; set; }

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<Batch> Batches { get; set; }
    }
}

Batcch Model Class

namespace TrainingManagementExistingDBCodeFirstShalvin.Models
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;

    [Table("Batch")]
    public partial class Batch
    {
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
        public Batch()
        {
            Attendances = new HashSet<Attendance>();
            Fees1 = new HashSet<Fee>();
            Students = new HashSet<Student>();
        }

        public int BatchId { get; set; }

        public int? CourseId { get; set; }

        [StringLength(40)]
        public string BatchName { get; set; }

        [Column(TypeName = "date")]
        public DateTime? StartDate { get; set; }

        [Column(TypeName = "date")]
        public DateTime? TentativeEndDate { get; set; }

        [StringLength(100)]
        public string BatchTiming { get; set; }

        public int? Hours { get; set; }

        public int? HoursTaken { get; set; }

        public int? Fees { get; set; }

        public int? FeesPaid { get; set; }

        [StringLength(15)]
        public string Status { get; set; }

        [StringLength(300)]
        public string Remarks { get; set; }

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<Attendance> Attendances { get; set; }

        public virtual Course Course { get; set; }

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<Fee> Fees1 { get; set; }

        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<Student> Students { get; set; }
    }
}

Attendance Model Class

namespace TrainingManagementExistingDBCodeFirstShalvin.Models
{
    using System;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;

    [Table("Attendance")]
    public partial class Attendance
    {
        public int AttendanceId { get; set; }

        public int? BatchId { get; set; }

        public int? FacultyId { get; set; }

        [Column(TypeName = "date")]
        public DateTime? Date { get; set; }

        public int? HoursTaken { get; set; }

        [StringLength(200)]
        public string CoveredModules { get; set; }

        [StringLength(200)]
        public string Remarks { get; set; }

        public virtual Batch Batch { get; set; }

        public virtual Faculty Faculty { get; set; }
    }
}

Attendance Module

[HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "AttendanceId,BatchId,FacultyId,Date,HoursTaken,CoveredModules,Remarks")] Attendance attendance)
        {
            if (ModelState.IsValid)
            {
                db.Attendances.Add(attendance);
                int intBatchId = Convert.ToInt32(Request.Form["BatchId"]);

                var Batch = (db.Batches.Where(b => b.BatchId == intBatchId)).FirstOrDefault();
                int intBatchHoursTaken = (int)Batch.HoursTaken;
                int intHoursTaken = Convert.ToInt32(Request.Form["HoursTaken"]);
                int intUpdatedHours = intBatchHoursTaken + intHoursTaken;
                Batch.HoursTaken = intUpdatedHours;
                 

                db.SaveChanges();
                return RedirectToAction("Index");
            }