topic Re: [resolved] how to get the column names in a data flow? in Talend Studio

[resolved] how to get the column names in a data flow?

Anonymous — Sat, 16 Nov 2024 13:58:16 GMT

Hi ,
I'd like to know how to get the column names of a table in a flow of data: excel, delimited or postgresql.
I have to compare them to the ones I should use. It could be via a tMap component.
I must follow a strict naming plan for files and their fields...
Would you know how to get that?
Thanks,
Mathieu

Re: [resolved] how to get the column names in a data flow?

Anonymous — Tue, 05 May 2009 02:35:10 GMT

Hello Mathieu
Try the code

String columnName=null;
for (java.lang.reflect.Field field: row1.getClass().getDeclaredFields()) {
      columnName=field.getName().toLowerCase();
       System.out.println(columnName);
     }

Best regards
shong

Re: [resolved] how to get the column names in a data flow?

Anonymous — Tue, 05 May 2009 08:19:35 GMT

thanks shong,
It works well, I get the column names.
They're printed out in the system.
But how to export them in a delimited file?
or make a column name a data flow so that it can be compared to a reference table via a tMap component?
Thanks again ,
Mathieu

Re: [resolved] how to get the column names in a data flow?

Anonymous — Tue, 05 May 2009 09:24:57 GMT

Hello

But how to export them in a delimited file?
or make a column name a data flow so that it can be compared to a reference table via a tMap component?

Define context variables to store the column name.
Best regards

shong

Re: [resolved] how to get the column names in a data flow?

Anonymous — Tue, 05 May 2009 12:37:40 GMT

OK thanks

Re: [resolved] how to get the column names in a data flow?

Anonymous — Wed, 07 Aug 2013 11:19:43 GMT

Hi,
It works correctly but I would to have access to the value or at least I would like to know if the value is null/blank. It can be a problem because I will have different type. Do you have an answer?
Thanks.

Re: [resolved] how to get the column names in a data flow?

alevy — Thu, 08 Aug 2013 02:18:06 GMT

Use tJavaRow instead of tJava, then:
Object objValue = field.get(input_row);
String fldType = field.getType().getName();
Once you know the field type you can convert the value to the appropriate type for comparisons.

Re: [resolved] how to get the column names in a data flow?

_AnonymousUser — Sat, 02 Aug 2014 16:26:26 GMT

plz can u tell me how to assign column names to context variable
thanks and regards
syed

Re: [resolved] how to get the column names in a data flow?

Anonymous — Sat, 02 Aug 2014 16:28:44 GMT

plz can u tell me how to assign column names to context variable
thanks and regards
syed

Re: [resolved] how to get the column names in a data flow?

Anonymous — Mon, 04 Aug 2014 06:39:11 GMT

plz can u tell me how to assign column names to context variable
thanks and regards
syed

Plz Give me a quick reply

Re: [resolved] how to get the column names in a data flow?

Anonymous — Mon, 04 Aug 2014 08:18:26 GMT

Hi Feroz,
Following code you can use in your tJavaRow...to get the column names to the context variable.
for (java.lang.reflect.Field field: row1.getClass().getDeclaredFields()) {
context.columnName = field.getName();
System.out.println("Field name is " + context.columnName );
}
You can extend this code for your design...
Vaibhav

Re: [resolved] how to get the column names in a data flow?

Anonymous — Mon, 27 Oct 2014 15:35:07 GMT

Hello,
I have the same problem: My job consists on doing the mapping of a XML file to a Csv file.But I want to have a second Csv file which contains the columns' names and types of the first.
Do you have an answer please??
Thanks

Re: [resolved] how to get the column names in a data flow?

Anonymous — Tue, 28 Oct 2014 08:16:57 GMT

Hi rloukil,

But I want to have a second Csv file which contains the columns' names and types of the first.

Could you please elaborate your case with an example with input and expected output values?

Best regards
Sabrina