Interview Q&A

• What is an alias and how does it differ from a synonym?

  An alias is an alternative to a synonym, designed for a distributed environment to avoid having to use the location qualifier of a table or view. The alias is not dropped when the table is dropped.

• What is a NULL value? What are the pros and cons of using NULLS?

  A NULL value takes up one byte of storage and indicates that a value is not present as opposed to a space or zero value.

• What is referential integrity?

  Referential integrity refers to the consistency that must be maintained between primary and foreign keys, i.e. every foreign key value must have a corresponding primary key value.

• Explain the EXPLAIN statement?

  The explain statement provides information about the optimizer's choice of access path of the SQL.

• How is the SUBSTR keyword used in SQL?

  SUBSTR is used for string manipulation with column name, first position and string length used as arguments. E.g. SUBSTR (NAME, 1 3) refers to the first three characters in the column NAME.

• What are some SQL aggregates and other built-in functions?

  The common aggregate, built-in functions are AVG, SUM, MIN, MAX, COUNT and DISTINCT.

• What keyword does an SQL SELECT statement use for a string search?

  The LIKE keyword allows for string searches. The % sign is used as a wildcard.

• What is the difference between group by and order by?

  Group by controls the presentation of the rows, order by controls the presentation of the columns for the results of the SELECT statement.

• What is a subselect? Is it different from a nested select?

  A subselect is a select which works in conjunction with another select. A nested select is a kind of subselect where the inner select passes to the where criteria for the outer select.

• Explain an outer join?

  An outer join includes rows from tables when there are no matching values in the tables

• What is Cookies collection?

  Cookies are text files that store information about the user by which the web server identifies and marks each different visitor to a web site and determines where a user has been before. A cookie can store information only when the user se...

• What is a TextStream object?

  It allows you to access(read/write) the contents of text files stored on the web server.

• What is Response Object?

  It controls the information sent to the user. The various methods are: Response.Write - Sends information directly to a browser Response.Redirect - Directs a user to a URL other than the requested URL Response.ContentType - Controls the...

• What is a FileSystemObject object?

  It provides access to the physical file system of the web server. It gets and manipulates information about all drives in a server, folders and sub-folders on a drive and files inside a folder.

• What is Server-Side includes?

  It provides extra information by which it makes the site easier to manage. It can include text files using the #include statement, retrieve the size and last modification date of a file, defines how variables and error messages are displaye...

• What is the difference between client-side script and server-side script?

  Scripts executed only by the browser without contacting the server is called client-side script. It is browser dependent. The scripting code is visible to the user and hence not secure. Scripts executed by the web server and processed by th...

• What are the ASP Scripting Objects?

  The Dictionary object, the FileSystemObject object, TextStream object.

• What is ServerVariables collection?

  The ServerVariables collection holds the entire HTTP headers and also additional items of information about the server. What is the difference between Querystring collection and Form collection? The main difference is that the Querystri...

• What are the methods in Session Object?

  The Session Object has only one method, which is Abandon. It destroys all the objects stored in a Session Object and releases the server resources they occupied.

• What is a “Virtual Directory”?

  Virtual directories are aliases for directory paths on the server. It allows moving files on the disk between different folders, drives or even servers without changing the structure of web pages. It avoids typing an extremely long URL each...

• How can you disable the browser to view the code?

  Writing codes within the Tag

• What is ASP?

  ASP stands for Active Server Pages. It is a server side technology which is used to display dynamic content on web pages. For example you could write code that would give your visitors different information, different images or even a total...

• Explain about returning values from subroutines (functions)?

  The return value of the subroutine is the value of the last expression evaluated or you can explicitly use a return statement to exit the subroutine specifying the return value. That return value is evaluated in the appropriate content depe...

• Explain about returning values from subroutines (functions)?

  The return value of the subroutine is the value of the last expression evaluated or you can explicitly use a return statement to exit the subroutine specifying the return value. That return value is evaluated in the appropriate content depe...

• What are the three ways to empty an array?

  The three different ways to empty an array are as follows 1) You can empty an array by setting its length to a negative number. 2) Another way of empting an array is to assign the null list (). 3) Try to clear an array by setting it to u...

• What exactly is grooving and shortening of the array?

  You can change the number of elements in an array simply by changing the value of the last index of/in the array $#array. In fact, if you simply refer to a non existent element in an array perl extends the array as needed, creating new elem...

• How to use the command shift?

  Shift array function shifts off the first value of the array and returns it, thereby shortening the array by one element and moving everything from one place to the left. If you don’t specify an array to shift, shift uses @ ARGV, the array...

• Is there any way to add two arrays together?

  Of course you can add two arrays together by using push function. The push function adds a value or values to the end of an array. The push function pushes the values of list onto the end of the array. Length of an array can be increased by...

• Explain about Typeglobs?

  Type globs are another integral type in perl. A typeglob`s prefix derefrencer is *, which is also the wild card character because you can use typeglobs to create an alias for all types associated with a particular name. All kinds of manipul...

• How does a “grep” function perform?

  Grep returns the number of lines the expression is true. Grep returns a sublist of a list for which a specific criterion is true. This function often involves pattern matching. It modifies the elements in the original list.

• Explain about an ivalue?

  An ivalue is an item that can serve as the target of an assignment. The term I value originally meant a “left value”, which is to say a value that appears on the left. An ivalue usually represents a data space in memory and you can store da...

• Name all the prefix dereferencer in perl?

  The symbol that starts all scalar variables is called a prefix dereferencer. The different types of dereferencer are. (i) $-Scalar variables (ii) %-Hash variables (iii) @-arrays (iv) &-subroutines (v) Type globs-*myvar stands for @myva...

• Explain about lists?

  A list is a construct that associates data elements together and you can specify a list by enclosing those elements in parenthesis and separating them with commas. They could themselves be arrays, hashes or even other lists. Lists do not ha...

• What are scalar variables?

  Scalar variables are what many programming languages refer to as simple variables. They hold a single data item, a number, a string, or a perl reference. Scalars are called scalars to differentiate them from constructs that can hold more th...

• What are the two different types of data perl handles?

  Perl handles two types of data they are (i) Scalar Variables and (ii) Lists Scalar variables hold a single data item whereas lists hold multiple data items.

• Which functions are available in the WMLscript Lang library?

  The functions in this section are accessed by Lang.functionName abs(number) returns the absolute value of number min(number1,number2) returns smallest of number1 and number2, or number1 if equal min(number1,number2) returns largest...

• When should I use WMLScript?

  The purpose of WMLScript is to provide client-side procedural logic. It is based on ECMAScript (which is based on Netscape’s JavaScript language), however it has been modified in places to support low bandwidth communications and thin clien...

• Can I use embedded WMLScript in my WML pages?

  No, you cannot use embedded WMLScript in your WML pages. You need to place your scripts in seperate files and reference them from your WML decks. Check the WMLScript tutorial to see how it's done.

• What is WMLScript?

  WMLScript is a subset of the JavaScript scripting language designed as part of the WAP standard to provide a convenient mechanism to access mobile phone’s peripheral functions.

• What are the three objects of ADO?

  objects of ADO are Command object, Connection object and Recordset object.

• What is the command or symbol used in VBScript for writing remarks?

  Using Rem keyword, you can add as many lines of comments as you want. Also single quotes can b e used to add comments

• What are the conditional statements used in VBScript?

  If then else and Select case

• hat are the types of arrays handled by VBScript?

  one dimensional array and multi dimensional array.

• What are the Platforms supported by VBScript?

  VBScript is supported by Windows 95, Windows NT (including a native version for Alpha), 16-bit Windows, and Unix Solaris. Microsoft is currently working with others to bring VBScript to UNIX versions for HP, Digital, and IBM platforms.

• What are the differences between the Dim, Public, and Private Statements in VBScript?

  Private statement variables are available only to the script in which they are declared. Public statement variables are available to all procedures in all scripts. Variables declared with Dim at the script level are available to all proce...

• What are the major differences between Visual Basic and VBScript?

  They are different: You dont compile VB scripts like in Visual Basic. You just distribute them as plain text HTML files.The script engine interprets this text into intermediate code when it loads the Web page. It also creates a symbol table...

• What is the use of ReDim statement in VBScript?

  The ReDim statement is used to change the size of the array within the script: for example you have declared an array Dim Customers(50) But now you want to change the size of the array so you can do that with the help of Redim ReDim...

• What are the data types supported by Vbscript?

  VB script supports only one datatype i.e ) Variant

• What are the differences between Sub-Procedure and a Function in VBScript?

  The main difference is function returns a value where as a Sub-procedure does not.

• What are the differences between Sub-Procedure and a Function in VBScript?

  The main difference is function returns a value where as a Sub-procedure does not.