Trim Char Datatype

[tkbharani]

Hi

I am trying to TRIM the Char datatype in Transformer stage.
Process
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Output column from teradata isCHAR datatype. At times when lookup fails the column will not be populated(It must be NULL). BUT when I try to check it for NULL or '' , its not working. When i check the length of the column its always 4, though in unix its is NULL.

I tried
TRIM(inputcolumn,'','D') -Not working
Convert() not working.

Any way to Trim the CHAR datatype , so that I can check IsNull function.

Thanks

[hamzaqk]

How are you extracting data from TD?? are you specifying a query to pull out data? if yes to the TRIM in the query.

[tkbharani]

Hi

I just used a copy stage between Teradatastage and Lookup stage, input column is CHAR and same column in output is VARCHAR. As I am checking for IsNull() its working fine.
If still there is way of triming in it transformer , please reply.

[chulett]

You can't trim a CHAR.