Skip to main content

User defined functions

User-Defined Functions allow to define its own T-SQL functions that can accept 0 or more parameters and return a single scalar data value or a table data type.


What kind of User-Defined Functions can be created?
There are three types of User-Defined functions in SQL Server 2000 and they are Scalar, Inline Table-Valued and Multi-statement Table-valued.

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.

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.

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 T-SQL 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.
Labels:

Comments

Post a Comment

Popular posts from this blog

How to Prevent Users to Press F5 key (Refresh button)

Some times we want to prevent user to Press F5 key to prevent Page Refresh. You can use the below script. Paste this code in the Head Section of your Page. <script language=javascript> document.onkeydown = function(){ if(window.event && window.event .keyCode == 116){ window.event.keyCode = 505; // Capture and remap F5 } if(window.event && window.event .keyCode == 505){ // New action for F5 return false; // Must return false }} </script>
7 comments
Read more

Access Different interface method with same Name implemented in a class

We use interface and multiple interface inherit it into class, then we implement the methods of interface as it is necessary but what will happen if two interface have the same mentods with same signature and inherited in the same class? Now questions arises from here are : Q1) Both the methods will be implementable which is with the same name and signature? Q2) If methods are implementable then how it is possible? Q3) If it is possible then can we access both the methods? Q3) If it is possible then what is the way to access these methods publically? The answer of all the above question is below: 1) Yes both the methods with same name and signature is implementable. 2) we have to implement interface explicitely preceding with iterface name. 3) Yes it is possible to access the methods. 4) Yes we can
Post a Comment
Read more

Should have on tips of our lips.........ACID PROPERTIES

Introduction    When ever we process any DML statements transactions are implicitly called. Ie. when ever no begin  transaction statement insert ,delete, update statements will have transaction statements around them implicitly. ACID concept is one of the oldest and important properties of the Database. It sets forward four goals that every database management system must strive to achieve: atomicity, consistency, isolation and durability. No database that fails to meet any of these four goals can be considered reliable. Atomicity Atomicity states that database modifications must follow an "all or nothing" rule. Each transaction is said to be "atomic." If one part of the transaction fails, the entire transaction fails. It is critical that the database management system maintain the atomic nature of transactions in spite of any DBMS, operating system or hardware failure. Consistency Consistency states that only valid data will be written to the database. If,...
2 comments
Read more