How many validation controls are available in ASP.NET AJAX 4.0?

The following validation controls are available in ASP.NET AJAX 4.0:

• FilteredTextBoxExtender - Enables you to apply filtering to a text box.
• MaskedEditExtender and MaskedEditValidator - Restricts a user to enter only a certain pattern of characters in the TextBox by applying a mask to the input.
• ValidatorCalloutExtender - Attaches to the ASP.NET validators so that the error messages are not displayed as a simple text but as a balloon-style ToolTip.
• NoBot - Prevents the spam/bot from filling the input forms automatically and uses the Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA), which is a type of challenge-response test to ensure that the response is not generated by the computer.
• PasswordStrengthExtender - Measures the strength of the password text entered within the text box by validating with the different strength specified parameters

Why do we use the UpdateProgress control in AJAX?

The UpdateProgress control is somewhat related to the UpdatePanel control. The UpdateProgress control enables you to design a user-friendly interface when a Web page consists of a number of UpdatePanel controls for partial-page rendering.

The UpdateProgress control makes you aware of the status information about the partial-page updates in the UpdatePanel control.

What are the new features of ASP.NET AJAX 4.0?

ASP.NET 4.0 AJAX includes several new features that provide more functionality to a user. These features are as follows:

• Support for live data binding.
• Support for client-side template rendering.
• Support for declarative instantiation of client components.
• Support for using the observer pattern on JavaScript objects and arrays.
• Support for invoking ADO.NET data services and data contexts.
• Support for the DataView control.

What are the new features included in the Microsoft AJAX library?

The Microsoft AJAX library is a client-based JavaScript library that is compatible with all modern browsers and offers a lot of functionality as compared to JavaScript. This library is released with new features and fully supports ASP.NET 4.0'. The new features included in the Microsoft AJAX library are as follows:

• Imperative syntax - Supports simple imperative syntax that is used to create and manage controls.
• Script loader - Retrieves all scripts that are needed by one or more client component or control automatically and executes the scripts in the order in which they are received.
• Client data access - Supports to access client data and display by client data control and client template.
• Client datacontext - Supports read and write permission to data from a database.
• The AdoNetDataContext class - Enables you to easily interact with an ADO.NET Data Services service.
• jQuery integration - Helps to access the elements in your Web pages, work with client-side events, enable visual effects, and make it easier to use AJAX in your applications.

What are the different controls of ASP.NET AJAX?

ASP.NET AJAX includes the following controls:

• ScriptManager
• ScriptManagerProxy
• UpdatePanel
• UpdateProgress
• Timer

How can we get the state of the requested process?

XMLHttpRequest get the current state of the request operation by using the readyState property. This property checks the state of the object to determine if any action should be taken. The readyState property uses numeric values to represent the state.

Why do we use the XMLHttpRequest object in AJAX?

The XMLHttpRequest object is used by JavaScript to transfer XML and other text data between client and server. The XMLHttpRequest object allows a client-side script to perform an HTTP request. AJAX applications use the XMLHttpRequest object so that the browser can communicate to the server without requiring a postback of the entire page. In earlier versions of Internet Explorer, MSXML ActiveX component is liable to provide this functionality; whereas, Internet Explorer 7 and other browsers, such as Mozilla Firefox, XMLHttpRequest is not liable to.

What technologies are being used in AJAX?

AJAX uses four technologies, which are as follows:

• JavaScript
• XMLHttpRequest
• Document Object Model (DOM)
• Extensible HTML (XHTML) and Cascading Style Sheets (CSS)

What is the difference between synchronous postback and asynchronous postback?

The difference between synchronous and asynchronous postback is as follows:

• Asynchronous postback renders only the required part of the page; whereas, synchronous postback renders the entire page for any postback.
• Asynchronous postback executes only one postback at a time, that is, if you have two buttons doing asynchronous postback, the actions will be performed one by one; whereas, synchronous postback executes all the actions at once.
• Asynchronous postback only modifies the update panel that raises the postback; whereas, synchronous postback modifies the entire page.

What is ASP.NET AJAX?

ASP.NET AJAX, mostly called AJAX, is a set of extensions of ASP.NET. It is developed by Microsoft to implement AJAX functionalities in Web applications. ASP.NET AJAX provides a set of components that enable the developers to develop applications that can update only a specified portion of data without refreshing the entire page. The ASP.NET AJAX works with the AJAX Library that uses object-oriented programming (OOP) to develop rich Web applications that communicate with the server using asynchronous postback.

What is DataWarehousing?

1. Subject-oriented, meaning that the data in the database is organized so that all the data elements relating to the same real-world event or object are linked together;
2. Time-variant, meaning that the changes to the data in the database are tracked and recorded so that reports can be produced showing changes over time;
3. Non-volatile, meaning that data in the database is never over-written or deleted, once committed, the data is static, read-only, but retained for future reporting.
4. Integrated, meaning that the database contains data from most or all of an organization's operational applications, and that this data is made consistent.

What is Identity?

Identity (or AutoNumber) is a column that automatically generates numeric values. A start and increment value can be set, but most DBA leave these at 1. A GUID column also generates numbers; the value of this cannot be controlled. Identity/GUID columns do not need to be indexed.

What is User Defined Functions? What kind of User-Defined Functions can be created?

User-Defined Functions allow defining its own T-SQL functions that can accept 0 or more parameters and return a single scalar data value or a table data type.
Different Kinds of User-Defined Functions created are:

1. Scalar User-Defined Function A Scalar user-defined function returns one of the scalar data types. Text, ntext, image and timestamp data types are not supported. These are the type of user-defined functions that most developers are used to in other programming languages. You pass in 0 to many parameters and you get a return value.
2. Inline Table-Value User-Defined Function An Inline Table-Value user-defined function returns a table data type and is an exceptional alternative to a view as the user-defined function can pass parameters into a T-SQL select command and in essence provide us with a parameterized, non-updateable view of the underlying tables.
3. Multi-statement Table-Value User-Defined Function A Multi-Statement Table-Value user-defined function returns a table and is also an exceptional alternative to a view as the function can support multiple T-SQL statements to build the final result where the view is limited to a single SELECT statement. Also, the ability to pass parameters into a TSQL select command or a group of them gives us the capability to in essence create a parameterized, non-updateable view of the data in the underlying tables. Within the create function command you must define the table structure that is being returned. After creating this type of user-defined function, It can be used in the FROM clause of a T-SQL command unlike the behavior found when using a stored procedure which can also return record sets.

What are primary keys and foreign keys?

Primary keys are the unique identifiers for each row. They must contain unique values and cannot be null. Due to their importance in relational databases, Primary keys are the most fundamental of all keys and constraints. A table can have only one Primary key. Foreign keys are both a method of ensuring data integrity and a manifestation of the relationship between tables.

What are different Types of Join?

1. Cross Join A cross join that does not have a WHERE clause produces the Cartesian product of the tables involved in the join. The size of a Cartesian product result set is the number of rows in the first table multiplied by the number of rows in the second table. The common example is when company wants to combine each product with a pricing table to analyze each product at each price.
2. Inner Join A join that displays only the rows that have a match in both joined tables is known as inner Join. This is the default type of join in the Query and View Designer.
3. Outer Join A join that includes rows even if they do not have related rows in the joined table is an Outer Join. You can create three different outer join to specify the unmatched rows to be included:
   1. Left Outer Join: In Left Outer Join all rows in the first-named table i.e. "left" table, which appears leftmost in the JOIN clause are included. Unmatched rows in the right table do not appear.
   2. Right Outer Join: In Right Outer Join all rows in the second-named table i.e. "right" table, which appears rightmost in the JOIN clause are included. Unmatched rows in the left table are not included.
   3. Full Outer Join: In Full Outer Join all rows in all joined tables are included, whether they are matched or not.
4. Self Join This is a particular case when one table joins to itself, with one or two aliases to avoid confusion. A self join can be of any type, as long as the joined tables are the same. A self join is rather unique in that it involves a relationship with only one table. The common example is when company has a hierarchal reporting structure whereby one member of staff reports to another. Self Join can be Outer Join or Inner Join.

What is sub-query? Explain properties of sub-query?

Sub-queries are often referred to as sub-selects, as they allow a SELECT statement to be executed arbitrarily within the body of another SQL statement. A sub-query is executed by enclosing it in a set of parentheses. Sub-queries are generally used to return a single row as an atomic value, though they may be used to compare values against multiple rows with the IN keyword.
A subquery is a SELECT statement that is nested within another T-SQL statement. A subquery SELECT statement if executed independently of the T-SQL statement, in which it is nested, will return a resultset. Meaning a subquery SELECT statement can standalone and is not depended on the statement in which it is nested. A subquery SELECT statement can return any number of values, and can be found in, the column list of a SELECT statement, a FROM, GROUP BY, HAVING, and/or ORDER BY clauses of a T-SQL statement. A Subquery can also be used as a parameter to a function call. Basically a subquery can be used anywhere an expression can be used.

What is Difference between Function and Stored Procedure?

UDF can be used in the SQL statements anywhere in the WHERE/HAVING/SELECT section where as Stored procedures cannot be. UDFs that return tables can be treated as another rowset. This can be used in JOINs with other tables. Inline UDF's can be thought of as views that take parameters and can be used in JOINs and other Rowset operations.

What is Collation?

Collation refers to a set of rules that determine how data is sorted and compared. Character data is sorted using rules that define the correct character sequence, with options for specifying case sensitivity, accent marks, kana character types and character width.