Vizlib Writeback Table Guides - Writeback Operations

Vizlib Writeback Table offers numerous operation types for writing or editing data back to your original source. They define whether you are replacing existing data, or inserting new data rows as part of your workflow.

This topic contains the following sections:

• Writeback Operations

• Update

•   Insert

• Overwrite

• Delete

Writeback Operations

Important: You must read and understand these operations as they are critical to the definition of your workflow and business process.

Overwrite	Insert	Delete	Update

Update

Update is the most sophisticated delta operation, which leaves unchanged data as it is, updating individual records and cells as the data is written back to the underlying source. It's different from Overwrite as it does not overwrite the complete source, allowing you to work, and edit a subset of the data.

Update is recommended if you wish to be able to work with Qlik Selections, and editing & writing data on a filtered data set. You can also include an audit trail with an Update operation.

As an example, you may have a table which supports multiple regions but wish to give the user rights to update records for one region only. Implementing Overwrite would replace the underlying source for a single region, whereas Update would keep all regions in the source, but only update the edited one.

Insert

Insert is the simplest operation as it adds all edited data as a new row(s) to the underlying data source. All edited data will be appended on writeback and when you load, you will receive all the history of written and edited data. This is particularly useful if you want to add adjustments to measures or correct data, but without losing any information on the state of the data before the change.

This means you would need to update your Qlik expressions in your dashboard, to ensure you

• choose the latest edited data (e.g. by using FirstSortedValue()).

• aggregate your information in some way (e.g. medium, max, min, sum).

With the Insert operation, you have two options:

• Insert All Rows: Inserts a copy of all rows visible in the table, edited or not edited, and appends it to the underlying data source.

• Insert Edited & New Rows (default): Only inserts edited rows & new rows.

Overwrite

Overwrite operation completely replaces the underlying data source with the newly modified data. Old values will not be kept, and there is no audit trail or versioning of the previous changes to the overwrite. You can, however, follow on an audit trail in which the user did the most recent changes.

Overwrite is particularly useful for mapping tables, reference files, or other static data, where the intention is to keep a single source of the truth, and only the latest version is relevant for your data analytics.

Delete

Delete only removes rows from the underlying data source. There are very rare use cases when this operation could be useful. As an example, you could implement it so that users can only remove values or rows from a given data set, such as:

• ticking off items

• removing duplicate rows

Track Unsaved Changes

The Track Unsaved Changes feature monitors the number of unsaved edits in Writeback Tables and displays this count through a configurable variable system. This feature is essential for maintaining data integrity in collaborative environments where multiple users are working with the same Qlik application simultaneously.

When enabled, this feature helps users:

• Monitor data changes before they are permanently saved.

• Prevent data loss in multi-user environments.

• Maintain awareness of pending changes across different tables.

The feature is supported in Qlik analysis mode.

Enable Changes Tracking

Before enabling this feature, ensure:

• You have created dedicated variables for tracking (one per Writeback Table extension)

• The Calculation Condition in Property Panel > Data Handling is set to less than 1.

Note: The Calculation Condition must be below 1 to ensure the tracking mechanism functions properly. This setting controls when the table recalculates and updates the tracking variable.

To enable the feature, follow these steps:

1. Go to Property Panel > Table Settings.

2. Locate the Track Unsaved Changes switch.

3. Toggle the switch to the Update Variable value.

When the feature is enabled, the system automatically counts each unsaved row edit as it occurs. The current count is written to your selected tracking variable whenever changes are made. The count updates in real-time as users make edits to table cells.

Important Considerations

When configuring the tracking feature, you need to be aware that the software may bring unexpected results when:

• The feature is being used in Qlik edit mode instead of analysis mode.

• The same variable is being updated in multiple Writeback Tables.

• The feature is used in conjunction with some other features influencing the data globally within the Writeback Table, such as Move Value Within Range in numeric columns and values in the data model initially being out of the defined range.