INDEX: SQL Tutorial

SQL Server Functions

SQL server has many built in functions -SQL Server Functions . Now many of us might be thinking that what are  SQL Server functions?, What are Built in functions?, How they work , and so on . This Article will guide you through Different SQL built in functions , and will discuss about the use of them .


What is Built in Functions?

Built in Functions are the piece of programming language that returns a output for the following input.
Ex: abs() abs function is used to return the absolute value.

SQL server functions -Numeric function [ABS()]-SELECT Abs(-1000.09) AS Example; 

O/P-Function of ABS() is to return the absolute value., and absolute value is to be stored in Example .

 Example
 1000

ABS(), COUNT(),RAND(), MIN(),ASCII() , and so on are the examples of SQL Server functions. Let us see each of them in detail, and enjoy the topic.


SQL Server String Functions

The following functions mentioned below are the Built-in functions in SQL with a “String “ type.

Function Description
ASCII Returns the ASCII value of the given Input (ASCII value-number )
CHAR Returns the ASCII character based on the given Input
CHARINDEX Returns the location of a substring in a string
CONCAT It’s  function is to concatenate 2 strings.
Concat with + Same function as CONCAT, but it can concatenate ‘2’ or more Strings
DATALENGTH Returns the length( in bytes), Expression Length is calculated using this function
LEFT Extracts a substring from a string (starting from left)
LEN Returns the length of the specified string , EX:2,3,4,any numeric value
LOWER A string is converted to a lowercase
LTRIM It removes spaces from a string
NCHAR Returns the Unicode character based on the Input mentioned
PATINDEX Returns the particular location of a pattern mentioned in the string
REPLACE Replaces a sequence of characters in a string with another set of characters
RIGHT Function Extracts a sub-string from a string (*from Right)
RTRIM Removes trailing spaces from a string
SPACE Returns a string with a specified number of spaces
STR It represents the string value of a particular number
STUFF Function Deletes a sequence of characters from a string and then insert the new pattern at the specified position.
SUBSTRING It extracts a Substring from a given string
UPPER It converts a String to Uppercase

SQL Server Numeric Functions

The following functions mentioned below are the Built-in Functions in SQL, and works on the numeric data.

Function Description
ABS It Returns the absolute value of a number
AVG It Returns the average value of an expression
CEILING It Returns the smallest integer value that is greater than or equal to a num
COUNT It Returns the count of an Input(Expression).
FLOOR Function is same as of  CEILING , Returns the largest integer value that is equal to or less than a number
MAX It Returns the maximum value of an expression
MIN It Returns the minimum value of an expression
RAND  It Returns a random number , The function produces a random number and it changes every second.
ROUND It Returns a number rounded to a certain number of decimal places
SIGN It Returns a value indicating the sign of a number
SUM  the summed value of an expression is returned

SQL Server Conversion Functions

SQL Server Conversion Functions are different from ‘String” , and other built in functions. They are used to change the Data type of an expression.

Function Description
CAST function helps to change the form of data type.
CONVERT CONVERT functions has the same functionality as of CAST , change the data type of an expression.

SQL Server Advanced Functions

This are some Advanced Built-in Functions used for the SQL. Advance function do not fall under the category of -‘String’ , ‘Numeric’,and other categoties of built-in functions.

Function Description
COALESCE Function is to Return the non-null expression in a list
CURRENT_USER As the function name suggest , It Returns the name of the current user in the SQL database.
ISDATE Returns 1 for the valid date , and ‘0’ for not. Functionality is same as of “BOOLEAN”  but returns ‘1’ and ‘0’
ISNULL As the name of the function suggests, It return an alt. value when an Expression=NULL value.
ISNUMERIC Returns 1 if the expression is a valid number, otherwise 0
NULLIF NULLIF compares ‘2’ expressions and gives the output
SESSION_USER Returns the user name of the current session in the SQL  database
SESSIONPROPERTY Returns the setting for a specified option of a session
SYSTEM_USER Returns the login name information for the current user in the SQL database.
USER_NAME Returns the user name in the SQL Server database

I hope that you like this article , for any doubts please drop your questions in the comment section down below.

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