File Reader (Complex Format)

This node can be used to read data from a file. It can be configured to read various formats.
When you open the node's configuration dialog and provide a filename, it tries to guess the reader's settings by analyzing the content of the file. Check the results of these settings in the preview table. If the data shown is not correct or an error is reported, you can adjust the settings manually (see below).

The file analysis runs in the background and can be cut short by clicking the "Quick scan", which shows if the analysis takes longer. In this case the file is not analyzed completely, but only the first fifty lines are taken into account. It could happen then, that the preview appears looking fine, but the execution of the File Reader (Complex Format) fails, when it reads the lines it didn't analyze. Thus it is recommended you check the settings, when you cut an analysis short.

Note: In case this node is used in a loop, make sure that all files have the same format (e. g. separators, column headers, column types). The node saves the configuration only during the first execution.
Alternatively, the File Reader node can be used.

This node can access a variety of different file systems. More information about file handling in KNIME can be found in the official File Handling Guide.


Read from
Select a file system which stores the model you want to read. There are four default file system options to choose from:
  • Local File System: Allows you to select a file from your local system.
  • Mountpoint: Allows you to read from a mountpoint. When selected, a new drop-down menu appears to choose the mountpoint. Unconnected mountpoints are greyed out but can still be selected (note that browsing is disabled in this case). Go to the KNIME Explorer and connect to the mountpoint to enable browsing. A mountpoint is displayed in red if it was previously selected but is no longer available. You won't be able to save the dialog as long as you don't select a valid i.e. known mountpoint.
  • Relative to: Allows you to choose whether to resolve the path relative to the current mountpoint, current workflow or the current workflow's data area. When selected, a new drop-down menu appears to choose which of the two options to use.
  • Custom/KNIME URL: Allows to specify a URL (e.g. file://, http:// or knime:// protocol). When selected, a spinner appears that allows you to specify the desired connection and read timeout in milliseconds. In case it takes longer to connect to the host / read the file, the node fails to execute. Browsing is disabled for this option.
It is possible to use other file systems with this node. Therefore, you have to enable the file system connection input port of this node by clicking the ... in the bottom left corner of the node's icon and choose Add File System Connection port .
Afterwards, you can simply connect the desired connector node to this node. The file system connection will then be shown in the drop-down menu. It is greyed out if the file system is not connected in which case you have to (re)execute the connector node first. Note: The default file systems listed above can't be selected if a file system is provided via the input port.
Enter a URL when reading from Custom/KNIME URL, otherwise enter a path to a file. The required syntax of a path depends on the chosen file system, such as "C:\path\to\file" (Local File System on Windows) or "/path/to/file" (Local File System on Linux/MacOS and Mountpoint). For file systems connected via input port, the node description of the respective connector node describes the required path format. You can also choose a previously selected file from the drop-down list, or select a location from the "Browse..." dialog. Note that browsing is disabled in some cases:
  • Custom/KNIME URL: Browsing is always disabled.
  • Mountpoint: Browsing is disabled if the selected mountpoint isn't connected. Go to the KNIME Explorer and connect to the mountpoint to enable browsing.
  • File systems provided via input port: Browsing is disabled if the connector node hasn't been executed since the workflow has been opened. (Re)execute the connector node to enable browsing.
The location can be exposed as or automatically set via a path flow variable.
Preserve user settings
If checked, the checkmarks and column names/types you explicitly entered are preserved even if you select a new file. By default, the analyzer starts with fresh default settings for each new file location.
If clicked, the file content is analyzed again. All settings are reset (unless the "Preserve user settings" option is selected) and the file is read in again to pre-set new settings and the table structure.
Read RowIDs
If checked, the first column in the file is used as RowIDs. If not checked, default row headers are created.
Read column headers
If checked, the items in the first line of the file are used as column names. Otherwise default column names are created.
Column delimiter
Enter the character(s) that separate the data tokens in the file, or select a delimiter from the list.
Ignore spaces and tabs
If checked, spaces and the TAB characters are ignored (not in quoted strings though).
Java style comment
Everything between '/*' and '*/' is ignored. Also everything after '//' until the end of the line.
Single line comment
Enter one or more characters that will indicate the start of a comment (ended by a new line).
Opens a new dialog with advanced settings. There is support for quotes, different decimal separators in floating point numbers, and character encoding. Also, for ignoring whitespaces, for allowing rows with too few data items, for making RowIDs unique (not recommended for huge files), for a global missing value pattern, and for limiting the number of rows read in.
Click on the table header
If the column header in the preview table is clicked, a new dialog opens where column properties can be set: name and type can be changed (and will be fixed then). A pattern can be entered that will cause a "missing cell" to be created when it's read for this column. Additionally, possible values of the column domain can be updated by selecting "Domain". And, you can choose to skip this column entirely, i.e. it will not be included in the output table then.

Input Ports

The file system connection.

Output Ports

Datatable just read from the file


This node has no views




You want to see the source code for this node? Click the following button and we’ll use our super-powers to find it for you.