Category Archives: Udf

Dates to “Long” – Friday function

August 3, 2012 1:00 pm / 3 Comments /

Time for another Friday function.

The ask

This time I was asked by our marketing bods to come up with something that made the dates in the SQL that is merged into our marketing and informational emails (glorified mail merge) from a dd/mm/yyyy (13/06/2012) or yyyy-mm-dd (2012-06-13) to a ddth MMM YYYY so becomes 13th June 2012.

They had been trying to do this themselves, with some mixed and non standard ways of doing it, generally it just made the code really hard to debug when they had issues, personally I could not find anything in the IBM info centre or online to do this so I created them a UDF that takes in a date and supplies out a “long” format date.

DB2 Date to “Long” format – Code


CREATE FUNCTION GLOBAL.CONVERT_DATE_LONG (IN_DATE DATE)
DETERMINISTIC
NO EXTERNAL ACTION
RETURNS VARCHAR(30)
LANGUAGE SQL
BEGIN ATOMIC
    ----------------------------------------------------------------------------
    ----------------------------------------------------------------------------
    --Takes Date in creates a long date
    ----------------------------------------------------------------------------
    ----------------------------------------------------------------------------

    ----------------------------------------------------------------------------
    ----------------------------------------------------------------------------
    --Declare Vars
    DECLARE OUT_DATE VARCHAR(30);
    DECLARE DATE_PART VARCHAR(4);
    DECLARE MONTH_PART VARCHAR(20);
    DECLARE YEAR_PART  VARCHAR(4);

    IF(IN_DATE IS NOT NULL) THEN
        ----------------------------------------------------------------------------
        ----------------------------------------------------------------------------
        --Set some vars
            --Get the Base Parts
            SET DATE_PART = DAY(IN_DATE, 2);
            SET MONTH_PART = MONTHNAME(IN_DATE);
            SET YEAR_PART = YEAR(IN_DATE,4);

            --Remove the 0 from the front of the date part
            IF(DATE_PART IN ('01','02','03','04','05','06','07','08','09')) THEN
                SET DATE_PART = RIGHT(DATE_PART,1);
            END IF;

            --Put the th nd or rd in the DATE_PART
            IF(DATE_PART IN ('3','23')) THEN 
                SET DATE_PART = DATE_PART || 'rd';
            ELSEIF (DATE_PART IN ('2','22')) THEN
                SET DATE_PART = DATE_PART || 'nd';
            ELSEIF (DATE_PART IN ('1','21','31')) THEN
                SET DATE_PART = DATE_PART || 'st';
            ELSE 
                SET DATE_PART = DATE_PART || 'th';
            END IF;

        ----------------------------------------------------------------------------
        ----------------------------------------------------------------------------
        --Set and return the result    
        SET OUT_DATE = DATE_PART || ' ' || MONTH_PART || ' ' || YEAR_PART;

        RETURN OUT_DATE;
   ELSE
        RETURN NULL;
   END IF;

END

Queston?

Is it that there is not the function built into DB2 that does this or does everyone have something similar for the audience that they deal with?

Future Post

I will be looking at converting an integer that represents seconds into a time



Posted in: Convert, Date, DB2 Administration, DB2 Data Types, DB2 Development, IBM DB2 LUW, UDF, Uncategorized, User Defined Function, Varchar / Tagged: , , , , , , , ,

Time to “English” – Friday Function

July 20, 2012 12:00 pm / 2 Comments /

I though about starting a new series that I will add to over time the Friday function, I might not be able to create something as useful as Serge Rielau (@srielau) but maybe it will helpful to someone. Over the last few days I have been asked to some interesting things with “my” data like converting times to a more “friendly” format.

The ask

To convert my nicely cleansed times (19:47:45 or 04:23:32) from various non standard sources (the wonders of Big Data) into a time format that is more compatible with your average email reader (7:47pm or 4:23am) as opposed to a techie that might be all right with the nice 24 hour times. I did a lot of searching around and I could not find any inbuilt functions of DB2 LUW that would do this and so I had to create my own user defined function. Please if you know of anything feel free to correct me, but searching the info center then there was nothing.

DB2 Time to “English” – Code

CREATE FUNCTION GLOBAL.CONVERT_TIME_12H(IN_TIME TIME)
DETERMINISTIC
NO EXTERNAL ACTION
RETURNS VARCHAR(10)
LANGUAGE SQL
BEGIN ATOMIC
    ----------------------------------------------------------------------------
    ----------------------------------------------------------------------------
    --Takes 24hrs time in gives back 12hrs time suffixed with AM or PM
    ----------------------------------------------------------------------------
    ----------------------------------------------------------------------------
    DECLARE OUT_TIME VARCHAR(10);

    IF(INT(LEFT(IN_TIME,2)) <= 12) THEN
        SET OUT_TIME = LEFT(IN_TIME,5) || 'am';

        IF(INT(LEFT(IN_TIME,2)) IN (10,11)) THEN
            RETURN REPLACE(OUT_TIME,'.',':');
        ELSE
            RETURN REPLACE(SUBSTR(OUT_TIME,1),'.',':');
        END IF;

    ELSE
        IF(INT(LEFT(IN_TIME,2)) = 24) THEN
            SET OUT_TIME = '00:00am';
        ELSE
            SET OUT_TIME = LEFT((IN_TIME - 12 HOURS),5) || 'pm';
        END IF;

        RETURN REPLACE(OUT_TIME,'.',':');
    END IF;

END

As you can see it takes in standard DB2 time, and I think managed to get all the gotchas like midnight not being 12 hours less. The downside of this function is that the format becomes text and therefore not useable so would not recommend using it for anything but for human format. As I said before if you know of a function to do this in DB2 that is built in I would love to know.

Future articles

In future Friday Functions then I will look at covering non standard asks that I have been required to do. I think after this one I will be needing to create a function to “elongate” a date!



Posted in: Convert, DB2 Data Types, DB2 Development, IBM DB2 LUW, Time, UDF, User Defined Function, Varchar / Tagged: , , , , , ,

Can’t Believe DB2 does not have this function – Convert Times

May 15, 2012 8:40 pm / Leave a Comment /

Seen as though DB2 LUW has had a major update 10.1, and I have not got round to blogging about it thought there was no point as everyone else has done it to death by now and maybe I can at later date if I see a hole someone has missed. Over the last few day I have been asked to some interesting things with “my” data like converting times to a more “friendly” format

So I needed to convert my nicely cleansed times (19:37:45 or 04:23:32) into a time format that is more compatible with your average email reader (2:30pm or 5:20am) as opposed to  a techie that might be all right with the nice 24 hour times. I did a lot of searching around and I could not find any inbuilt functions of DB2 LUW that would do this and so I had to create my own user defined function. Please if you know of anything feel free to correct me, but searching the info center then there was nothing.

CREATE FUNCTION GLOBAL.CONVERT_TIME_12H(IN_TIME TIME)
DETERMINISTIC
NO EXTERNAL ACTION
RETURNS VARCHAR(10)
LANGUAGE SQL
BEGIN ATOMIC
    ----------------------------------------------------------------------------
    ----------------------------------------------------------------------------
    --Takes 24hrs time in gives back 12hrs time suffixed with AM or PM
    ----------------------------------------------------------------------------
    ----------------------------------------------------------------------------
    DECLARE OUT_TIME VARCHAR(10);

    IF(INT(LEFT(IN_TIME,2)) <= 12) THEN
        SET OUT_TIME = LEFT(IN_TIME,5) || 'am';

        IF(INT(LEFT(IN_TIME,2)) IN (10,11)) THEN
            RETURN REPLACE(OUT_TIME,'.',':');
        ELSE
            RETURN REPLACE(SUBSTR(OUT_TIME,1),'.',':');
        END IF;

    ELSE
        IF(INT(LEFT(IN_TIME,2)) = 24) THEN
            SET OUT_TIME = '00:00am';
        ELSE
            SET OUT_TIME = LEFT((IN_TIME - 12 HOURS),5) || 'pm';
        END IF;

        RETURN REPLACE(OUT_TIME,'.',':');
    END IF;

END

As you can see it takes in standard DB2 time, and I think managed to get all the gotchas like midnight not being 12 hours less. As I said before if you know of a function to do this in DB2 that is built in I would love to know.

Posted in: Data types, DB2, DB2 Administration, DB2 built in functions, IBM, LEFT, Time, UDF, User Defined Functions