tLogRow is one of the easiest and most used components in Talend Studio. While it is mostly used for adding runtime logging information, it can also be used for debugging a Talend Studio Job.
In the Job shown below, the output from the tMap component is passed to a
tLogRow component, which logs the row data in the console.
To have tLogRow logging row data in this subJob, you'll need to modify the tMap
configuration by clearing the Die on error check box to make sure that the Job
does not terminate on a failed row.
When you run the Job after making these changes, the tLogRow outputs the
successful rows from the tMap; it also shows an error for failed rows, which you
can use to troubleshoot the data issues.
For debugging purposes, you may need to print intermediate variables created by the
tMap component. These may not be necessarily part of the tMap output
and, therefore, won’t show up in the console using a tLogRow. A simple way to
capture these tMap variables is to use a Java println function in the
tMap Expression Builder, as shown below.
The console output displays the value of the tMap variable.
