Nulls in hash file 2

[ritanya]

Hi All,

I'm having null values to most of the columns (apart for key column)and i need to pass through hash file. My question is, how the hash file will react or treat for the null columns? help me.

Thanks in advance.

Ritanya

 

[JGirl]

>I'm having null values to most of the columns
>(apart for key column)and i need to pass through
>hash file.

Hi Ritanya,

Can you please clarify what you are trying to achieve? Are you simply trying to write null values to a hash file, or are you using a hash file as a reference table in an attempt to eliminate the null columns from your original input data?

I may be able to help you out, but Im not sure what you are trying to achieve at the moment.

J

 

[ritanya]

Hi J,
I'm using hash file as a reference table in an attempt to eliminate the null columns from my original input data. Also, i would like to know how hash file handles the null values????

Thanks

 

[JGirl]

Hi,

Your hash file will handle the null values however you tell it to.

For example, say your job is something like the following (this is a mega simle example):
HASH_FILE
|
|
lnkLookup
|
|
V
INPUT_FILE ----lnkInput---->TRANSFORMER----lnkOutput---->OUTPUT_FILE

For this example:
* lnkInput & lnkOutput are stream links
* lnkLookup is your reference link (ie. your lookup to the HASH_FILE)
* All files contain 2 fields, "Client_Number" and "Client_Name"
* In the INPUT_FILE, the Client_Name field may be null
* In the HASH_FILE, the Client_Name field is not null
* In the OUTPUT_FILE, the Client_Name field will be derived from HASH_FILE if it is null in the INPUT_FILE

Firstly, in the transformer stage you will need to link INPUT_FILE.Client_Number to HASH_FILE.Client_Number so that the lookup works.

Secondly, in the column derivation for OUTPUT_FILE.Client_Name you will need to have something like (the syntax here isnt 100% correct):
if ((len(INPUT_FILE.Client_Name)=0 OR (INPUT.FILE.Client_Name=@NULL)) AND (len(HASH_FILE.Client_Name) > 0)) then
HASH_FILE.Client_Name
else
INPUT_FILE.Client_Name

Hope this helps

Cheers
J

 

[JGirl]

Woops....looks like my little diagram got messed up. In case you didnt figure it out, the lnkLookup is meant to connect to the TRANSFORMER.

J

 

[ritanya]

Thanks a lot J