Chapter 48. Common Properties of Writers

Writers are the final components of the transformation graph. Each writer must have at least one input port through which the data flows to this graph component from some of the others. The writers serve to write data to files or database tables located on disk or to send data using some FTP, LDAP or JMS connection. Among the writers, there is also the Trash component which discards all of the records it receives (unless it is set to store them in a debug file).

In all writers it is important to decide whether you want either to append data to the existing file or sheet or database table (Append attribute for files, for example), or to replace the existing file or sheet or database table by a new one. The Append attribute is set to false by default. That means "do not append data, replace it".

It is important to know that you can also write data to one file or one database table by more writers of the same graph, but in such a case you should write data by different writers in different phases.

Remember that (in case of most writers) you can see some part of resulting data when you right-click a writer and select the View data option. After that, you will be prompted with the same View data dialog as when debugging the edges. For more details see Viewing Debug Data. This dialog allows you to view the written data (it can only be used after graph has already been run).

Here we present a brief overview of links to these options:

Here we present an overview of all Writers:

Table 48.1. Writers Comparison

Component	Data output	Input ports	Output ports	Transformation	Transf. required	Java	CTL
Trash	none	1	0
CSVWriter	flat file	1	0-1
CloudConnectDataWriter	CloudConnect binary file	1	0
GD Dataset Writer	GoodData dataset	1	0