Category Archives: Functions

CHOOSE LOGICAL FUNCTION IN SQL SERVER 2012

Functions, Logical Functions, Sql Server, Sql Server 2012, , , ,

CHOOSE is one of the new built-in logical function introduced as a Part of Sql Server 2012. It returns the value at the specified index position from the list of values.

SYNTAX: CHOOSE ( index, val_1, val_2 [, val_n ] )

Example 1: CHOOSE Basic Example

SELECT CHOOSE(1,'Spring','Summer','Autumn','Winter')
SELECT CHOOSE(2,'Spring','Summer','Autumn','Winter')
SELECT CHOOSE(3,'Spring','Summer','Autumn','Winter')
SELECT CHOOSE(4,'Spring','Summer','Autumn','Winter')

Result:
CHOOSE_LOGICAL_FUNCTION_SQL_SERVER_2012_1

Example 2: CHOOSE function with variables as index and values.

DECLARE @SeasonId INT = 2, @Season1 Varchar(10) = 'Spring',
 @Season2 Varchar(10) = 'Summer',@Season3 Varchar(10) = 'Autumn',
 @Season4 Varchar(10) = 'Winter'

SELECT CHOOSE(@SeasonId, @Season1, @Season2, @Season3, @Season4)

Result: Summer

Example 3: CHOOSE will return NULL if INDEX position is outside the range of values.

SELECT CHOOSE(-10,'Spring','Summer','Autumn','Winter')
SELECT CHOOSE(0,'Spring','Summer','Autumn','Winter')
SELECT CHOOSE(5,'Spring','Summer','Autumn','Winter')

Result:
CHOOSE_LOGICAL_FUNCTION_SQL_SERVER_2012_2

Example 4: If index value is numeric, it will be implicitly converted to INT.

SELECT CHOOSE(3.1,'Spring','Summer','Autumn','Winter')
SELECT CHOOSE(3.85,'Spring','Summer','Autumn','Winter')

Result:
CHOOSE_LOGICAL_FUNCTION_SQL_SERVER_2012_3

Example 5: CHOOSE function Return Datatype will be the one with highest precedence from the Datatypes of the list of values

SELECT CHOOSE(3, 40.58, 50, 60, 70)

Result: 60.00

Example 6: CHOOSE function with Index Type as Varchar

SELECT CHOOSE('TEST','Spring','Summer','Autumn','Winter')

Result:
Msg 245, Level 16, State 1, Line 1
Conversion failed when converting the varchar value ‘TEST’ to data type int.

SELECT CHOOSE('3','Spring','Summer','Autumn','Winter')

Result: Autumn

You may like to read the below new built-in function’s introduced in Sql Server 2012:

New Built in Functions introduced in Sql Server
CONVERSION FUNCTIONS
PARSE TRY_PARSE
TRY_CONVERT
STRING FUNCTIONS
CONCAT FORMAT
LOGICAL FUNCTIONS
CHOOSE IIF
DATE AND TIME FUNCTIONS
EOMONTH
DATEFROMPARTS DATETIMEFROMPARTS
SMALLDATETIMEFROMPARTS DATETIME2FROMPARTS
TIMEFROMPARTS DATETIMEOFFSETFROMPARTS

Please correct me, if my understanding is wrong. Comments are always welcome.

IIF() LOGICAL FUNCTION IN SQL SERVER 2012

Functions, Logical Functions, Sql Server, Sql Server 2012, , ,

IIF() is one of the new built-in logical function introduced as a Part of Sql Server 2012. IIF() is the shorthand way of writing CASE statement or IF-ELSE statement. In-fact if we see the execution plan the IIF() function internally translates to a CASE statement.

IIF() function takes three arguments, first argument should be a Boolean expression otherwise it raises an exception. If Boolean expression evaluates to TRUE then Second argument will be the result otherwise Third argument will be the result. This functions result’s Datatype will be the one with highest precedence from the Datatypes of Second and Third Argument.

Syntax: IIF ( boolean_expression, true_value, false_value )

Now let us understand this function with examples:

Example 1: Comparing two Integer numbers

SELECT IIF(1 > 10, 'TRUE', 'FALSE' )

Result: FALSE

Example 2: Comparing two Integer Variables

DECLARE @Marks INT = 60, @Minimum INT = 35
SELECT IIF(@Marks >= @Minimum, 'PASS', 'FAIL' )

Result: PASS

Example 3: Comparing Strings

DECLARE @NAME Varchar(50) = 'Basav'
SELECT IIF(@NAME IN ('Basav','Kalpana'), 
                    'Likes SQL', 'Likes ORACLE' )

Result: Likes SQL

Example 4: Result’s Datatype will be the one with highest precedence from the Datatypes of Second and Third Argument.

SELECT IIF(1 > 10, 1.5, 40)

Result: 40.0

Example 5: Nested IIF() Statement.

DECLARE @Percentage AS NUMERIC(5,2) = 71
SELECT IIF(@Percentage >= 70, 'Distinction', 
        IIF(@Percentage>=35 AND @Percentage<70, 'Pass', 'Fail'))

Result: Distinction

Note: As IIF() statement internally translates to an CASE statement, so the Max Nesting level is 10.

Example 6: IIF() with both return value arguments value as NULL constant

SELECT IIF(1 > 2, NULL, NULL)

Result:
Msg 8133, Level 16, State 1, Line 1
At least one of the result expressions in a CASE specification must be an expression other than the NULL constant

Example 7: IIF() with on of the return value argument value as NULL constant

SELECT IIF(1 > 2, NULL, 'NO')

Result: NO

Example 8: IIF() with both return value arguments are variables with value NULL

DECLARE @A INT = NULL, @B INT = NULL
SELECT IIF(1 > 2, @A, @B)

Result: NULL

You may also like to read other LOGICAL FUNCTION CHOOSE() introduced in SQL SERVER 2012

Please correct me, if my understanding is wrong. Comments are always welcome.

You may like to read the below new built-in function’s introduced in Sql Server 2012:

New Built in Functions introduced in Sql Server
CONVERSION FUNCTIONS
PARSE TRY_PARSE
TRY_CONVERT
STRING FUNCTIONS
CONCAT FORMAT
LOGICAL FUNCTIONS
CHOOSE IIF
DATE AND TIME FUNCTIONS
EOMONTH
DATEFROMPARTS DATETIMEFROMPARTS
SMALLDATETIMEFROMPARTS DATETIME2FROMPARTS
TIMEFROMPARTS DATETIMEOFFSETFROMPARTS

TRY_PARSE CONVERSION FUNCTION IN SQL SERVER 2012

Conversion Functions, Functions, Sql Server, Sql Server 2012, , , , , , ,

TRY_PARSE is one of the new built-in conversion function introduced as a Part of Sql Server 2012. TRY_PARSE function is Similar to PARSE function, but if PARSE function fails to convert the value throws an exception where as TRY_PARSE function returns a NULL value.

Important Note: TRY_PARSE function is not a native SQL SERVER function, instead it is a .NET Framework Common Language Run-time dependent function. Then obviously it will have the performance overhead and also requires the presence of .NET CLR on the database Server. Continue to use the existing CAST and CONVERT functions wherever it is possible.

Syntax:  TRY_PARSE ( string_value AS data_type [ USING culture ] )

Parameter Details:
string_value : String expression which needs to be parsed.
data_type : Output data type, e.g. INT, NUMERIC, DATETIME etc.
culture : Optional string that identifies the culture in which string_value is formatted. If it is not specified, then it takes the language of the current session.

Now let us understand this TRY_PARSE function with examples:

-- TRY_PARSE String to INT
SELECT TRY_PARSE('1000' AS INT) AS 'String to INT'
-- TRY_PARSE String to NUMERIC
SELECT TRY_PARSE('1000.06' AS NUMERIC(8,2)) 
           AS 'String to NUMERIC'
-- TRY_PARSE String to DATETIME
SELECT TRY_PARSE('05-18-2013' AS DATETIME) 
           AS 'String to DATETIME' 
-- TRY_PARSE String to DateTime
SELECT TRY_PARSE('2013/05/18' AS DATETIME) 
           AS 'String to DATETIME'
-- TRY_PARSE string value in the India date format to DATETIME
SELECT TRY_PARSE('18-05-2013' AS DATETIME using 'en-in') 
 AS 'String in the India date format to DATETIME'
-- TRY_PARSE string value is in the US currency format to Money 
SELECT TRY_PARSE('$2500' AS MONEY using 'en-US')
 AS 'String in the US currency format to MONEY'

Result:
TRY_PARSE_CONVERSION_FUNCTION_IN_SQL_SERVER_2012

Difference between PARSE and TRY_PARSE

Try to convert invalid value, in this case PARSE throws exception but TRY_PARSE returns NULL Value

SELECT PARSE('Basavaraj' as DATETIME) 'PARSE RESULT'
GO
SELECT TRY_PARSE('Basavaraj' as DATETIME) 'TRY_PARSE RESULT'

Result:

PARSE RESULT
———————–
Msg 9819, Level 16, State 1, Line 1
Error converting string value ‘Basavaraj’ into data type datetime using culture ”.

TRY_PARSE RESULT
———————–
NULL

Below example demonstrate how we can check the result of TRY_PARSE function in IF condition:

IF  TRY_PARSE('Basavaraj' as DATETIME) IS NULL
           PRINT 'TRY_PARSE: Conversion Successful'
ELSE
           PRINT 'TRY_PARSE: Conversion Unsuccessful'

Result:
TRY_PARSE: Conversion Successful

You may like to read the below new built-in function’s introduced in Sql Server 2012:

New Built in Functions introduced in Sql Server
CONVERSION FUNCTIONS
PARSE TRY_PARSE
TRY_CONVERT
STRING FUNCTIONS
CONCAT FORMAT
LOGICAL FUNCTIONS
CHOOSE IIF
DATE AND TIME FUNCTIONS
EOMONTH
DATEFROMPARTS DATETIMEFROMPARTS
SMALLDATETIMEFROMPARTS DATETIME2FROMPARTS
TIMEFROMPARTS DATETIMEOFFSETFROMPARTS