Sunday 31 July 2011

Functions in Informatica

1 Character Functions:

1.1 LENGTH:

The LENGTH function returns the number of characters in a string, including trailing blanks. It is available in the Designer and the Workflow Manager.

LENGTH (string)

Example: The following expression returns the length of each customer name:

LENGTH (CUSTOMER_NAME)

CUSTOMER_NAME

Leonardo

NULL

Edwin Britto

1.2 LPAD:

RETURN VALUE

8

NULL

12

The LPAD function adds a set of blanks or characters to the beginning of a string, to set a string to a specified length. It is available in the Designer and the Workflow Manager.

LPAD (first_string, length [, second_string])

Example: The following expression standardizes numbers to five digits by padding them with leading zeros.

LPAD (NUM, 5, '0')

NUM

1

250

1.3 LTRIM:

RETURN VALUE

00001

00250

The LTRIM function removes blanks or characters from the beginning of a string. It is available in the Designer and the Workflow Manager.

LTRIM (string [, trim_set])

LTRIM (string) removes the leading spaces or blanks from the string. When LTRIM function is used with a trim set, which is optional, it removes the characters in the trim set from the string.

Example : The following expression removes the leading zeroes in the port

ITEM_CODE.

LTRIM (ITEM_CODE,'0')

ITEM_CODE

006

0803

RETURN VALUE

6

803

* The LTRIM function can be nested when needed to remove multiple characters.

1.4 RPAD:

The RPAD function converts a string to a specified length by adding blanks or characters to the end of the string. It is available in the Designer and the Workflow Manager.

RPAD( first_string, length [, second_string ] )

Example: The following expression returns the string with a length of 5 characters, appending the string ':' to the end of each word:

RPAD (WORD, 5, ':’)

WORD

Date

Time

1.5 RTRIM:

RETURN VALUE

Date:

Time:

The RTRIM function removes blanks or characters from the end of a string. It is available in the Designer and the Workflow Manager.

RTRIM (string [, trim_set])

The RTRIM function can be combined with the LENGTH function if the trailing blanks are to be ignored. It can also be nested when needed to remove multiple characters.

RTRIM (string) removes the trailing spaces or blanks from the string. When RTRIM function is used with a trimset, which is optional, it removes the characters in the trimset from the string.

For example,

RTRIM (ITEM_CODE,'10')

The above expression removes the characters 10 in the port ITEM_CODE.

ITEM_CODE

0610

380

RETURN VALUE

06

38

In the second example the function removes the trailing zero since the RTRIM compares the first character in the trimset with the last character of the string, since it does not match it takes the second character in the trimset and compares with last character of the string. Since it matches it removes it.

1.6 SUBSTR:

The SUBSTR function returns a portion of a string. It is available in the Designer and the Workflow Manager.

SUBSTR( string, start [, length ] )

The SUBSTR may not give the desired result if the string on which it is used is not trimmed. Though it is always a good practice to trim the strings before using them in any expression, it becomes extremely important to trim them if they are used in a SUBSTR function.

For example, if there is a function

SUBSTR (NAME, 2,2)

It will not return the 2,3 characters of the NAME if the port has leading spaces. In this case LTRIM becomes essential.

SUBSTR(LTRIM(NAME),2,2)

The SUBSTR function can also be used to get the last few characters as described below.

SUBSTR(NAME,-3,3)

This function will return the last three characters of the string. But it may not return the required last three characters if the port has trailing blanks, hence RTRIM is essential.

SUBSTR(RTRIM(NAME),-3,3)

Hence it is always better to trim the strings before using them in a SUBSTR function.

SUBSTR(LTRIM(RTRIM(NAME)),3,2)

The above expression will get the 3,4 character of the port NAME irrespective of whether the port has leading or trailing blanks or not.

2 Conversion Functions:

2.1 TO_CHAR:

The TO_CHAR function converts numeric values and dates to text strings. It is available in the Designer and the Workflow Manager.

TO_CHAR( numeric_value )

TO_CHAR (date [, format ] )

Example : The following expression converts the values in the SALES port to text:

TO_CHAR (SALES )

SALES

1800.03

-22.57891

RETURN VALUE

'1800.03'

'-22.57891'

The following expression converts the dates in the DATE_PROMISED port to text in the format MON DD YYYY:

TO_CHAR (DATE_PROMISED, 'MON DD YYYY' )

DATE_PROMISED

Apr 1 1998 12:00:10AM

RETURN VALUE

'Apr 01 1998'

If we omit the format_string argument, TO_CHAR returns a string in the default date format ‘MM/DD/YYYY’.

We can use Conversion functions with DATE functions in order to do some calculations.

The following composite expression converts the string DATE_PROMISED to date, adds 1 to it and then converts the same to text string with the format YYYYMMDD.

TO_CHAR(ADD_TO_DATE(TO_DATE(DATE_PROMISED),'DD',1),'YYYYMMDD')

Test functions can also be used with Conversion functions.

The following expression uses IS_DATE along with TO_CHAR.

IS_DATE(TO_CHAR(DATE_PROMISED,'YYYYMMDD'))

* TO_CHAR returns NULL if invalid Date is passed to the function.

2.2 TO_DATE:

The TO_DATE function converts a character string to a date datatype in the same format as the character string. It is available in the Designer and the Workflow Manager.

TO_DATE( string [, format ] )

Example : The following expression returns date values for the strings in the DATE_PROMISED port. TO_DATE always returns a date and time. If we pass a string that does not have a time value, the date returned always includes the time 00:00:00. If we execute a session in the twentieth century, the century will be 19.

The current year on the machine running the Informatica Server is 1998:

TO_DATE( DATE_PROMISED, 'MM/DD/YY' )

DATE_PROMISED

'12/28/81'

NULL

RETURN VALUE

Dec 28 1981 00:00:00

NULL

The format of the string must exactly be the format given in the TO_DATE function.

* TO_DATE function fails if invalid date entries are given. To avoid this we must use IS_DATE function to check if the string has a valid date to be converted.

2.3 TO_DECIMAL:

The TO_DECIMAL function converts any value (except binary) to a decimal. It is available in the Designer.

TO_DECIMAL( value [, scale ] )

Example : This expression uses values from the port IN_TAX. The datatype is decimal with precision of 10 and scale of 3:

TO_DECIMAL( IN_TAX, 3 )

IN_TAX

'15.6789'

NULL

'A12.3Grove'

RETURN VALUE

15.678

NULL

0

We can also use two conversion functions together in a single expression.

The following expression uses the functions TO_DECIMAL and TO_CHAR.

TO_DECIMAL(TO_CHAR(DATE_PROMISED,'YYYYMMDD'))

2.4 TO_FLOAT:

The TO_FLOAT function converts any value (except binary) to a double-precision floating point number (the Double datatype). It is available in the Designer and the Workflow Manager.

TO_FLOAT( value )

Example : This expression uses values from the port IN_TAX:

TO_FLOAT( IN_TAX )

IN_TAX

'15.6789'

NULL

2.5 TO_INTEGER:

RETURN VALUE

15.6789

NULL

The TO_INTEGER function converts any value (except binary) to an integer by rounding the decimal portion of a value. It is available in the Designer and the Workflow Manager.

TO_INTEGER( value )

Example : This expression uses values from the port IN_TAX:

TO_INTEGER( IN_TAX )

IN_TAX

'15.6789'

'60.2'

RETURN VALUE

16

60

3 Date Functions:

Date Format Strings in the Transformation Reference

D, DD, DDD, DAY, DY, J

Days (01-31). We can use any of these format strings to specify the entire day portion of a date. For example, if we pass 12-APR-1997 to a date function, we can use any of these format strings specify 12.

HH, HH12, HH24

Hour of day (0 to 23), where zero is 12 AM (midnight). We can use any of these formats to specify the entire hour portion of a date. For example, if we pass the date 12-APR-1997 2:01:32 PM, we can use HH, HH12, or HH24 to specify the hour portion of the date.

MI

Minutes.

MM, MON, MONTH

Month portion of date (0 to 59). We can use any of these format strings to specify the entire month portion of a date. For example, if we pass 12-APR-1997 to a date function, we can use MM, MON, or MONTH to specify APR.

SS , SSSS

Second portion of date (0 to 59).

Y, YY, YYY, YYYY , RR

Year portion of date (1753 to 9999). We can use any of these format strings to specify the entire year portion of a date. For example, if we pass 12-APR-1997 to a date function, we can use Y, YY, YYY, or YYYY to specify 1997.

3.1 ADD_TO_DATE

The ADD_TO_DATE function adds a specified amount to one part of a date/time value, and returns a date in the same format as the specified date.

Note: If we do not specify the year as YYYY, the Informatica Server assumes the date is in the current century. It is available in the Designer and the Workflow Manager.

ADD_TO_DATE( date, format, amount )

Example : The following expression adds one month to each date in the

DATE_SHIPPED port. If we pass a value that creates a day that does not exist in a particular month, the Informatica Server returns the last day of the month. For example, if we add one month to Jan 31 1998, the Informatica Server returns Feb 28 1998.

Also note, ADD_TO_DATE recognizes leap years and adds one month to Jan 29 2000:

ADD_TO_DATE( DATE_SHIPPED, 'MM', 1 )

DATE_SHIPPED

Jan 12 1998 12:00:30AM

RETURN VALUE

Feb 12 1998 12:00:30AM

The following expression subtracts 10 days from each date in the DATE_SHIPPED port:

ADD_TO_DATE( DATE_SHIPPED, 'D', -10 )

DATE_SHIPPED

Jan 1 1997 12:00:30AM

RETURN VALUE

Dec 22 1996 12:00AM

The following expression subtracts 15 hours from each date in the DATE_SHIPPED port:

ADD_TO_DATE( DATE_SHIPPED, 'HH', -15 )

DATE_SHIPPED

Jan 1 1997 12:00:30AM

RETURN VALUE

Dec 31 1996 9:00:30AM

In ADD_TO_DATE function, if the argument passed evaluates to a date that does not exist in a particular month, the Informatica Server returns the last day of the month.

The following expression reveals this.

ADD_TO_DATE( DATE_SHIPPED, 'MON', 3 )

DATE_SHIPPED

Jan 31 1998 6:24:45PM

3.2 DATE_COMPARE

RETURN VALUE

Apr 30 1998 6:24:45PM

The DATE_COMPARE function returns a value indicating the earlier of two dates. It is available in the Designer and the Workflow Manager.

DATE_COMPARE( date1, date2 )

Example : The following expression compares each date in the DATE_PROMISED and DATE_SHIPPED ports, and returns an integer indicating which date is earlier:

DA DATE_COMPARE ( DATE_PROMISED, DATE_SHIPPED )

DATE_PROMISED

Jan 1 1997

Feb 1 1997

Dec 22 1997

3.3 DATE_DIFF

DATE_SHIPPED

Jan 13 1997

Feb 1 1997

Dec 15 1997

RETURN VALUE

-1

0

1

The DATE_DIFF function returns the length of time between two dates, measured in the specified increment (years, months, days, hours, minutes, or seconds). It is available in the Designer and the Workflow Manager.

DATE_DIFF( date1, date2, format )

Example: The following expressions return the number of days between the DATE_PROMISED and the DATE_SHIPPED ports:

DATE_DIFF DATE_DIFF ( DATE_PROMISED, DATE_SHIPPED, 'D' )

DATE_DIFF DATE_DIFF ( DATE_PROMISED, DATE_SHIPPED, 'DD' )

DATE_PROMISED

Jan 1 1997 12:00:00AM

Mar 29 1997 12:00:00PM

DATE_SHIPPED

Mar 29 1997 12:00:00PM

Jan 1 1997 12:00:00AM

RETURN VALUE

-87.5

87.5

We can combine DATE functions and TEST functions so as to validate the dates.

For example, while using the DATE functions like DATE_COMPARE and DATE_DIFF, the dates given as inputs can be validated using the TEST function IS_DATE and then passed to them if valid.

3.4 GET_DATE_PART

The GET_DATE_PART function returns the specified part of a date as an integer value, based on the default date format of MM/DD/YYYY HH24:MI:SS. It is available in the Designer and the Workflow Manager.

GET_DATE_PART( date, format )

Example: The following expressions return the day for each date in the

DATE_SHIPPED port:

GE GET_DATE_PART ( DATE_SHIPPED, 'D' )

GEGET_DATE_PART ( DATE_SHIPPED, 'DD' )

DATE_SHIPPED

Mar 13 1997 12:00:00AM

June 3 1997 11:30:44PM

NULL

3.5 LAST_DAY

RETURN VALUE

13

3

NULL

The LAST_DAY function returns the date of the last day of the month for each date in a port. It is available in the Designer and the Workflow Manager.

LAST_DAY( date )

Example : The following expression returns the last day of the month for each date in

the ORDER_DATE port:

LAST_DAY( ORDER_DATE )

ORDER_DATE

RETURN VALUE

Apr 1 1998 12:00:00AM

Jan 6 1998 12:00:00AM

Apr 30 1998 12:00:00AM

Jan 31 1998 12:00:00AM

DATE functions combine with Conversion functions also.

The following expression has LAST_DAY and TO_DATE functions nested or combined together.

LAST_DAY( TO_DATE( GIVEN_DATE, 'DD-MON-YY' ))

3.6 MAX

The MAX function returns the latest date found in a group. It is available in the Designer.

MAX( date, filter_condition )

We can return the maximum date for a port or group.

Example: The following expression returns the maximum order date for flashlights:

MAX( ORDERDATE, ITEM_NAME='Flashlight' )

ITEM_NAME

Flashlight

Regulator System

Flashlight

Diving Hood

Halogen Flashlight

Flashlight

RETURN VALUE: Oct 10 1998

3.7 MIN

ORDER_DATE

Apr 20 1998

May 15 1998

Sep 21 1998

Aug 18 1998

Feb 1 1998

Oct 10 1998

The MIN function returns the earliest date found in a group. It is available in the Designer.

MIN( date, filter_condition )

Example: The following expression returns the oldest order date for flashlights:

MIN( ORDER_DATE, ITEM_NAME='Flashlight' )

ITEM_NAME

Flashlight

Regulator System

Flashlight

Diving Hood

ORDER_DATE

Apr 20 1998

May 15 1998

Sep 21 1998

Aug 18 1998clip_image004[8]

Halogen Flashlight

Flashlight

RETURN VALUE: Feb 1 1998

3.8 ROUND

Feb 1 1998

Oct 10 1998

The ROUND function rounds one part of a date. It is available in the Designer and the Workflow Manager.

ROUND( date [, format ] )

Example: The following expressions round the month portion of each date in the DATE_SHIPPED port.

ROUND( DATE_SHIPPED, 'MM' )

ROUND( DATE_SHIPPED, 'MON' )

DATE_SHIPPED

Jan 15 1998 2:10:30AM

RETURN VALUE

Jan 1 1998 12:00:00AM

Similarly the ROUND function can be used to round off Year, Day or Time portions.

3.9 SET_DATE_PART

The SET_DATE_PART function sets one part of a date/time value to a specified value. It is available in the Designer and the Workflow Manager.

SET_DATE_PART( date, format, value )

Example: The following expressions change the month to June for the dates in the DATE_PROMISED port. The Informatica Server displays an error when we try to create a date that does not exist, such as changing March 31 to June 31:

SET_DATE_PART( DATE_PROMISED, 'MM', 6 )

SET_DATE_PART( DATE_PROMISED, 'MON', 6 )

DATE_PROMISED

Jan 1 1997 12:15:56AM

NULL

RETURN VALUE

Jun 1 1997 12:15:56AM

NULL

Similarly the SET_DATE_PART function can be used to round off Year, Day or Time portions.

3.10 TRUNC

The TRUNC function truncates dates to a specific year, month, day, hour, or minute. It is available in the Designer and the Workflow Manager.

TRUNC( date [, format ] )

Example: The following expressions truncate the year portion of dates in the DATE_SHIPPED port:

TRUNC( DATE_SHIPPED, 'Y' )

TRUNC( DATE_SHIPPED, 'YY' )

DATE_SHIPPED

Jan 15 1998 2:10:30AM

RETURN VALUE

Jan 1 1998 12:00:00AM

Similarly the TRUNC function can be used to truncate Month , Day or Time portions.

The functions TRUNC & ROUND can be nested in order to manipulate dates.

4 Special Functions:

4.1 DECODE

The DECODE function searches a port for the specified value. It is available in the Designer and the Workflow Manager.

DECODE( value, first_search, first_result [, second_search, second_result ]…[, default ] )

Example: We might use DECODE in an expression that searches for a particular ITEM_ID and returns the ITEM_NAME:

DECODE( ITEM_ID, 10, 'Flashlight',

14, 'Regulator',

20, 'Knife',

40, 'Tank',

'NONE' )

ITEM_ID

10

14

17

4.2 IIF

RETURN VALUE

Flashlight

Regulator

NONE

The IIF function returns one of two values we specify, based on the results of a condition. It is available in the Designer and the Workflow Manager.

IIF( condition, value2 [, value2 ] )

Example : IIF( SALES < 100, 0, SALARY )

SALES

150

50

SALARY

50,000.00

20,000.00

RETURN VALUE

50,000

0

NULL

50,000.41

50,000

IIF functions can be nested if there is more than one condition to be tested. But it is always a better option to go for DECODE function when the number of conditions is large since DECODE function is less costlier compared to IIF function.

For example consider the following expression

IIF(MARKS>=90,'A',

(IIF(MARKS>= 75,'B',

(IIF(MARKS>=65,'C',

(IIF(MARKS>=55,'D',

IIF(MARKS>=45,'E',

'F'))))))))

The same result can be obtained with

DECODE(TRUE,

MARKS>=90,'A',

MARKS>=75,'B',

MARKS>=65,'C',

MARKS>=55,'D',

MARKS>=45,'E',

'F')

When the number of conditions increase we will be able to appreciate the simplicity of the DECODE function and the complexity of the IIF function.

In both the cases , If MARKS>90 it will return 'A' though it satisfies all the conditions given. It is because it returns when the first condition is satisfied.

Therefore even if a port satisfies two or more the conditions it will take only the first one. Therefore Ordering is important in IIF and DECODE functions.

4.3 ERROR:

The ERROR function causes the Informatica Server to skip a record and throws an error message defined by the user. It is available in the Designer.

ERROR( string )

Example : The following example shows how you can reference a mapping that calculates the average salary for employees in all departments of your company, but skips negative values. The following expression nests the ERROR function in an IIF expression so that if the Informatica Server finds a negative salary in the Salary port, it skips the row and displays an error:

IIF( SALARY < 0, ERROR ('Error. Negative salary found. Row skipped.', EMP_SALARY )

SALARY RETURN VALUEclip_image004[11]

10000 10000

-15000 'Error. Negative salary found. Row skipped.'

The below example combines two special functions, a test Function and a conversion function.

IIF(IS_DATE(DATE_PROMISED,'MM/DD/YY'),TO_DATE(DATE_PROMISED),ERROR('Invalid

Date'))

4.4 LOOKUP:

The LOOKUP function searches for a particular value in a lookup source column. It is available in the Designer.

LOOKUP( result, search1, value1 [, search2, value2]… )

Example : The following expression searches the lookup source :TD.SALES for a specific item ID and price, and returns the item name if both searches find a match:

LOOKUP( :TD.SALES.ITEM_NAME, :TD.SALES.ITEM_ID, 10, :TD.SALES.PRICE, 15.99 )

ITEM_NAME

Regulator

Flashlight

5 Test Functions:

5.1 ISNULL

ITEM_ID

5

10

PRICE

100.00

15.99

The ISNULL function returns whether a value is NULL. It is available in the Designer and the Workflow Manager.

ISNULL( value )

Example : The following example checks for null values in the items table:

ISNULL ISNULL ( ITEM_NAME )

ITEM_NAME

Flashlight

NULL

''

5.2 IS_DATE

RETURN VALUE

0 (FALSE)

1 (TRUE)

0 (FALSE) Empty string is not NULL

The IS_DATE function returns whether a value is a valid date. It is available in the Designer and the Workflow Manager.

IS_DATE( value )

Example : The following expression checks the INVOICE_DATE port for valid dates:

IS_DATE( INVOICE_DATE )

This expression returns data similar to the following:

INVOICE_DATE

NULL

180

'04/01/98'

'04/01/1998 00:12:15'

'02/31/1998 12:13:55'

'John Smith'

RETURN VALUE

NULL

0 (FALSE)

0 (FALSE)

1 (TRUE)

0 (FALSE) (February does not have 31 days)

0 (FALSE)

This function can also be used to validate a date for a specified format for which the

syntax is

IS_DATE( value, format )

If the format is not specified, ‘MM/DD/YYYY’ is taken as the default format.

5.3 IS_NUMBER

The IS_NUMBER returns whether a string is a valid number. It is available in the Designer and the Workflow Manager.

IS_NUMBER( value )

Example : The following expression checks the ITEM_PRICE port for valid numbers:

IS_NUMBER( ITEM_PRICE )

ITEM_PRICE

123.00

-3.45e+3

''

+123abc

ABC

-ABC

NULL

RETURN VALUE

1 (True)

1 (True)

0 (False) Empty string

0 (False)

0 (False)

0 (False)

NULL

5.4 IS_SPACES

The IS_SPACES function returns whether a value consists entirely of spaces. It is available in the Designer and the Workflow Manager.

IS_SPACES( value )

Example : The following expression checks the ITEM_NAME port for rows that consist entirely of spaces:

IS_SPACES IS_SPACES ( ITEM_NAME )

ITEM_NAME

Flashlight

Regulator

system

RETURN VALUE

0 (False)

1 (True)

0 (False)