The following node is available in the Open Source KNIME predictive analytics and data mining platform version 2.7.1. Discover over 1000 other nodes, as well as enterprise functionality at http://knime.com.

CSV Writer

This node writes out the datatable coming through its input port into a file. The node provides many options to customize the output format (see below). But there is no checking done on the settings, so it is possible to write out the data in a format that makes it impossible to read it in again (e. g. if you specify no data separator).

Dialog Options

Output file location
Enter a valid file name. You can also choose a previously selected file from the drop-down list, or select a file from the "Browse..." dialog.
Write column header
If checked, the column names will be written out in the first line of the output file.
Don't write column headers if file exists
If checked, the column headers will not be written when the output is appended to the already existing output file. This is particularly useful when the csv writer is used in a LOOPER node to report results. This option is ignored when the column header is not written anyway or the file append option is unchecked (see below).
Write row ID
If checked, the row IDs will be added to the output, as first item in each line.
Compress output file (gzip)
Compress the output file in gzip format. If enabled, you will not be able to append to an existing file.
If file exists...
Specify the behavior of the node in case the output file already exists. Overwrite will replace any existing file, Append will append the input table to the end of the file (possibly skipping the column header) and Abort will issue an error during the node's execution (to prevent unintentional overwrite).
Data Separator
In the Advanced tab, you can specify the character(s) that will be written out between the data items. You can use "\t" for a tab or "\n" for a new line character (and must use "\\" for a backslash) in any character sequence.
Missing Value Pattern
In the Advanced tab, enter a pattern that will be written out for missing data values. Note, the missing value pattern will never be put into quotes (see below).
Quote Pattern
In the Quotes tab, you can enter a left and right quotation mark pattern. Also, select a mode, which determines when quotation marks should be placed around the data item. When quotes are used (in every mode other than "never") you must also specify a replacement pattern for the right quote. If it appears in the data item, it must be replaced (so it won't be confused with the actual closing quote).
Quote Mode: always
Every data item written out is placed between quotation marks. (The missing value pattern is not quoted though.)
Quote Mode: if needed
Quotes are only placed around a data item that contains the data separator (specified in the Advanced tab) or if it equals the missing value pattern. The right quote pattern will be replaced if it appears in a quoted data item.
Quote Mode: non-numerical only
Integer and floating point numbers are not quoted, all other data items are. (Selecting the decimal point as data separator will lead to an output that can't be read in again.) The right quote is replaced in quoted items.
Quote Mode: never
No data item is placed between quotation marks. You should specify a replacement pattern for the data separator, if it occurs in the data item.
Comment Header
In the Comment Header tab you can add a comment header to the beginning of the output. Either specify your own comment line(s) or choose from the predefined items. If you check one of the options you must also enter a comment begin and comment end pattern.
Header Content: the current creation time
If checked, a comment line with the current time and date is added.
Header Content: the user account name
If checked, the login name of the user that created the file (probably you!) is inserted.
Header Content: the input table name
If checked, a comment line is added showing the name of the table the data was read from.
Header Content: this text
If you check this, you can enter any text, that will be added then to the comment header. Use "\n" to start a new line, and "\t" to insert a tab character (and "\\" to produce a backslash).
Comment Pattern
If you have checked at least one of the content options, you must provide comment begin and end patterns that are placed around the comment header then. If you omit the end pattern the begin pattern is placed at the beginning of each comment line (assuming single line comments, in contrast to block comment if you specify both patterns).
Decimal Separator
In the tab "decimal separator" you can enter a character that is used as decimal separator for floating point numbers. It replaces the default character '.' then.

Ports

Input Ports
0 The Datatable to write out.
This node is contained in KNIME Base Nodes provided by KNIME GmbH, Konstanz, Germany.