topic Re: What is Count(*) in Java Script in Talend Studio

What is Count(*) in Java Script

Anonymous — Tue, 07 May 2019 21:58:50 GMT

Hello Talend Community,

I need a tMap Java Script Expression that would do the same thing as a COUNT(*) in SQL. This will be used in a Output Column in tMap Output Column Not a tJava Component.Need something similar to a ((Integer)globalMap.get("tFileInputDelimited_1_NB_LINE")) you would use in a tJava Component. Not sure what the alternative it is in a tMap Expression

-Andrew

Re: What is Count(*) in Java Script

TRF — Tue, 07 May 2019 22:28:17 GMT

In tMap you can use a sequence to count rows one by one. The final result will be available with the last row. You may also, store the result in a global variable. For that, define a local variable inside the tMap, for exemple i with the expression "0;". The semi-column is important as it allows you to write something else after such as "globalMap.put("count", Numeric.sequence("x", 1);" (this should work but not too clean in my opinion).
However, using a tAggregateRow is probably a better approach in most cases.