How to Navigate in Asp.net and Database Handling

Navigation in Asp.net

This article explains how to do navigation in Asp.net

##Basic Info before studying further

#Switch - single expression, multiple output

#If then else - multiple expression, multiple output

# File > New project> Language C#

Website > browse >“give any name” > save and ok

Click on website > Add> New item > webform 

View> Solution Explorer

#How to create Starup page

Goto Solution Explorer>Right click on page> set as start up page

#How to navigate

//Response.Redirect

//Server.Transfer

//Server.Execute

* Server.Transfer only works with aspx pages not html

* Response.Redirect works with both pages

* Server.Transfer only works with internal url not external url

* Response.Redirect works with both url

* Server.Transfer – for security reason url remain same. Only works with internet.

* Response.Redirect – here it changes

* Server.Transfer is better than Response.Redirect in performance

* Server.Execute only execute not display

# Click on Default.aspx

In Toolbox > Standard > Button

In Toolbox > Standard > Hyperlink

#Now Double Click on Button

protected void Button1_Click(object sender, EventArgs e)         {             Response.Redirect("default.aspx");         }     }

#  Now Right click on Hyperlink

Navigate url: default2.aspx

# Double click on Default page, then right click >Break point> Insert Breakpoint

# So that page will not scroll

<%Page.MaintainScrollPositionOnPostBack="true"

# Database Handling

* Database – There are 2 types

1. File Server Database

2. Client Server Database

* File Server Database – Its for single user application. At a time single user operates. Ex – notepad, MS Access

* Client Server Database- Its for multi user application. Ex – MS SQL, Oracle, MY SQL

Client Server – MSSQL SERVER

MSSQL SERVER – CLR (Compatible + Better Performance)

# Database

SQL- Structure Query Language – It is base language for all databases. It is non- procedural language[Procedure language cannot be made]. It is simple English language.

T-SQL – Transact SQL

1. Triggers

2. Stored procedure

3. Functions

4. Indexes

5. Views

6. Cursors

clr is inbuilt in SQL

#Different Editions of SQL

* MSSQL SERVER – SQL EXPRESS -7.5,2000, 2005, 2008(for student only)

* MSSQL SERVER DEV – paid / canbe used in companies

* MSSQL SERVER STD –used in big companies

* MSSQL SERVER ENT – for secured db

# Which types of files or extensions are in MSSQL

.mdf - Primary file

.ldf – Log file

.ndf – Secondary File

.sdf- Mobile database

# Role of these files

.mdf – For 1 database ,1 file is made. Max size – 8 gb (for express version).There is only one Primary file.

.ldf – [log file/transaction log file]- if .mdf file is corroupted then data can be recovered from it.

.ndf – When file size of primary is increased then secondary file will be made. Use defined file. Secondary file can be multiple.

.sdf – It is compact file. There is only single file. For mobile applications.

# How to create database

Click on View> Server Explorer(Open Vs)

* Server explorer – to manage database

Application server – for asp.net application (It runs on this server)

Database server – For database application

Server > DESKTOP-I3R20OL(it will different for every user)

Instance name(to differentiate or to access) - SQLEXPRESS

Ø Right click on Data connection> Create New SQL Server database

Ø Server name - DESKTOP-I3R20OL\SQLEXPRESS (will be according to user pc or laptop)

Ø Windows Authentication – can access windows user

Ø New database name – dbemployee(can be any)

Dataconnection>desktop-i3r20ol\sqlexpress.dbemployee.dbo

Select your database> Right Click on Table > Add New table

Change table name – employee

# Types of integers in MSSQL SERVER

1. Tiny int – 1 bytes =0-255 integer

2. Small int – 2 bytes

3. Int – 4 Bytes

4. Big int – 8 bytes

* Datatype – int (acc to capacity or required by client)

* Emp no. should not be duplicate for that

Constrain (validation check)– primary key

*Primary key

Ø To be used for not null and unique

Ø Multiple primary key cannot be made

Ø When primary is made, index is applied to it

*Index – To retrieve data fast

# Which Index is applied

*Cluster index- for primary key, one table, one cluster index

*Non- cluster index- one table upto 249 clusters

# Primary key v/s Unique

Primary key	Unique
One table, one key	One table, multiple unique
It is not null and unique	It is unique and null can come but only once

# Table

Emp no.

Ename

*String data – varchar type

Varchar- 8000 characters can be stored

Varchar(Max)- 2gb

Nvarchar- 4000(Multilanguage)

Nvarchar(max)- 2gb

# Data type

*CHAR – Fixed length(same memory for storing one or more characters)

*VARCHAR- To store non-unique code value

*NVARCHAR- Store unique code value

*VARCHAR- It takes 1 or 3 bytes extra

*CHAR- It is fixed

*VARCHAR= 0-255 – then 1 byte extra

                    = >255- 2 bytes extra

# Why extra bytes

When converging from 1 data type to other data type

#How many columns in one table

In MSSQL 2007

Sparse column – 30,000

Non- sparse column – 1024

*Sparse column- Used when value is maximum null. As it reduces the size upto 40%

# In Table

Name	Data Type	Allow Null
empno	int
ename	Varchar(50)	Y
eadd	Varchar(50)	Y
esal	int	y

Click on update (top left corner) > update database