The following node is available in the Open Source KNIME predictive analytics and data mining platform version 2.8.0. Discover over 1000 other nodes, as well as enterprise functionality at http://knime.com.

String Manipulation

Manipulates strings like search and replace, capitalize or remove leading and trailing white spaces.

To remove leading and trailing blanks from a column with name c0 you would use the expression:
strip($c0$)

If you have your customer names in column names with titles Mr and Mister and you want to normalize the data so that only Mr is used you could use the expression:
replace($names$, "Mister", "Mr")
or you could combine it to
replace(replace($names$, "Mister", "Mr"), "Miss", "Ms")

Or if you want to have the number of characters of the strings in a column with name text:
length($text$)

Note that strings which are part of the expression and are not from the input data (or the result of another wrapped function call) need to be enclosed in double quotes ('"'). Additionally, if the string contains a quote character, it must be escaped using a backslash character ('\"'). Finally, other special characters such as single quotes and backslashes need to be escaped using a backslash. For instance, a single backslash in a string is written as two consecutive backslash characters; the first one acts as the escape character for the second.

Dialog Options

Column List

The list contains the column that are available in the input table. Double click any of the column names to insert the respective field in the expression editor. It will replace your current selection or simply insert at the current caret position.

Flow Variable List

The list contains the flow variables that are currently available at the node input. Double clicking any of the entries will insert the respective identifier at the current cursor position (replacing the selection, if any).

Function

Select a single function to display its description. A double click will insert the function in the expression editor. It will replace your current selection or simply insert at the current caret position. Select a category to narrow down the list of displayed functions.

Expression

The place for your business logic. You can hit ctrl+space to get an auto completion box.

Replace/Append

Specify here if you want the result to be put into a separate or existing column.

Insert Missing As Null

If selected, missing values in the input table will be represented by null in the expression. If unselected, a missing value in the input will produce a missing output cell without evaluating the expression.

Syntax check on close

If unchecked the dialog can be closed even when the expression has syntax errors.

Ports

Input Ports

0	Input table.

Output Ports

0	Input table with an additional calculated column or one column replaced.