Similar LPAD function in DB2

[ajongba]

Hi All,
I am new to DB2 and was just wondering how to update my existing table a column of which has to be left padded with zeros.
Here is the scenerio :-
My table column is a varchar(30) which contains characters ranging from 0(null) to 30 now what i want to do is for those characters whose length is less than 6 should be padded with zero and leave the rest as it is ..also i would like the values to be the same with just the zeros padded wherever required.

example:-
null should be updated to 000000
1 should be updated to 000001
12 should be updated to 000012
123 should be updated to 000123
.....
123456 should be updated to 123456


Help would be really appreciated.

[sakumar9]

Hi All,
I am new to DB2 and was just wondering how to update my existing table a column of which has to be left padded with zeros.
Here is the scenerio :-
My table column is a varchar(30) which contains characters ranging from 0(null) to 30 now what i want to do is for those characters whose length is less than 6 should be padded with zero and leave the rest as it is ..also i would like the values to be the same with just the zeros padded wherever required.

example:-
null should be updated to 000000
1 should be updated to 000001
12 should be updated to 000012
123 should be updated to 000123
.....
123456 should be updated to 123456


Help would be really appreciated.

There is no such direct function. Alternatively you can have some function that will do the required concatenation. For this, you can use CONCAT() function to manually do the concatenation depending upon the string size.


Regards
-- Sanjay

[sakumar9]

If you have any problems in writing the function, then I can help you out.

Regards
-- Sanjay

[ajongba]

If you have any problems in writing the function, then I can help you out.

Regards
-- Sanjay

I think that would be really helpful if you can show me in detail how to achieve this.....

Thanks alot

[sakumar9]

Sure, I will try to give you the code, but that may not be possible today. I can send you the code by tomorrow.

Regards
-- Sanjay

[ajongba]

Sure, I will try to give you the code, but that may not be possible today. I can send you the code by tomorrow.

Regards
-- Sanjay

That is quite fine by me.... I will be looking forward to this.....

Thanks

[docdiesel]

Hi,

for a start you should change the NULL values to '0'. After this, the following UPDATE stmt should do:

update
  mytable
set
  numtxtcol = (
    concat(
      substr( '000000', 1, 6-length( numtxtcol ) ),
      numtxtcol
    )
  )
where
  length( numtxtcol ) < 6

Means, slice the leading zero chars you need from the fixed string '000000' and concatenate them with your varchar value before replacing the original value with the concatenated one - if it's less than six chars.

Regards,

Bernd

[docdiesel]

Hi,

hm, I missed your discussion. These things happen if you leave your browser window open for hours ... do you need to do this just once, repeatedly or every time data is written to the varchar() column?

If you need to do this just once, my script from above should be fine. If you need to have it left padded with zeros every time something gets written to that column, I suggest some other path: Modify that column to a nullable integer column and add a second which is generated automatically with sql like the following:

ALTER TABLE
  my.table
ADD COLUMN
  padded_int
GENERATED ALWAYS AS
(
  concat(
    substr( '000000', 1,  5 - int(log10( int_col ))  ),
    char( int_col )
  )
)  ;

This is just to show how to do it so I've not included the code for the NULL values. But you may easily solve this by adding a CASE statement (NULL -> '000000').

Regards,

Bernd

[ajongba]

Hi,

hm, I missed your discussion. These things happen if you leave your browser window open for hours ... do you need to do this just once, repeatedly or every time data is written to the varchar() column?

If you need to do this just once, my script from above should be fine. If you need to have it left padded with zeros every time something gets written to that column, I suggest some other path: Modify that column to a nullable integer column and add a second which is generated automatically with sql like the following:

ALTER TABLE
  my.table
ADD COLUMN
  padded_int
GENERATED ALWAYS AS
(
  concat(
    substr( '000000', 1,  5 - int(log10( int_col ))  ),
    char( int_col )
  )
)  ;

This is just to show how to do it so I've not included the code for the NULL values. But you may easily solve this by adding a CASE statement (NULL -> '000000').

Regards,

Bernd

okey... thank you for the help...it is working for me....as you suggested i changed the null values first then applied the first update statement.....
Just for your info i have to use it just for one time as the expected data from then on would be in the proper format...

Thanks again for your valuable input......