Charts

Charts are the visualization of data from a dataset in the form of a table, diagram, or map.

DataLens includes two types of charts:

• Dataset-based charts
• QL charts

Dataset-based charts

Charts are created in a wizard based on data from one or multiple datasets (see multi-dataset charts).
You can create an unlimited number of charts based on a single dataset.

The workspace in the wizard interface is divided into three main panels:

1. A dataset panel where available fields are displayed: Dimensions and Measures. You can add a calculated field to the list.
2. A visualization setup panel that you can use to select a chart type. Each type has its own set of sections (such as X-axis, Y-axis, and filters) where you can drag and drop fields. Learn more in Chart settings.
3. A preview panel where the visualization is displayed.

Charts let you quickly analyze and test hypotheses. You can also save charts and add them to dashboards as widgets.

Multi-dataset charts

Multi-dataset charts display data from multiple datasets.

Queries for each dataset are processed independently of each other. You cannot create calculated fields from fields in multiple datasets.
When you add a second dataset DataLens, the link is automatically created based on the first match for the field name and field data type.

In this case, you can:

• Change links.
• Add new links.
• Delete links.

Specifics of working with linked datasets in the chart, except for geochart layers:

• One chart can use any measures from datasets, regardless of their links.
• One chart can only use linked dimensions.
• Filters by linked dimensions are applied to all datasets.
• Filters by non-linked dimensions are applied only to their own dataset.

Working with linked datasets in geovisualizations on different layers:

• A geolayer can use any measures from datasets regardless of their links
• A geolayer can only use its linked dimensions.
• Filters by linked dimensions from the General filters section are applied to all datasets in all layers.
• Filters from the General filters section that use non-linked dimensions only apply to their own dataset in all layers.
• Filters in the Layer filters section that use linked dimensions apply to all datasets within the current layer.
• Filters in the Layer filters section that use non-linked dimensions only apply to their own dataset within the current layer.
• There are no restrictions on using non-linked dimensions in different layers.

QL charts

QL charts are charts created from a connection if the connection target is a database. Use a SQL query to build these charts. The query is executed using the original database's SQL flavor, which helps expand visualization capabilities by using database-specific transactions.

Executing a SQL query does not set up a separate Dataset object, but rather generates one on the fly and displays it in the preview panel.

Unlike regular charts, the logic of using the wizard in QL charts favors the SQL query, that is, the wizard only displays data from a query.

QL chart features:

• They reduce database workload by using direct queries.
• They are only suitable for SELECTs.
• They enable the use of the JOIN, GROUP BY, and SORT BY operators as well as aggregate functions in a SQL query.
• They enable the parameterization of any part of a SQL query.
• They support a limited set of visualizations types.
• They have public access restrictions.
• They do not support data materialization.
• They do not use RLS or calculated fields.

SELECT Category, Month, ROUND(SUM(Sales))
FROM samples.SampleLite
WHERE Category in {{category}} -- a variable used in the selector
GROUP BY Category, Month -- grouping by category and month
ORDER BY Category, Month -- sorting by category and month

To create a QL chart, see the instructions.

Publishing a chart

You can grant any internet user access to a chart using DataLens Public. This chart becomes public and any user can view it without authorization.

To grant public access to a chart:

1. On the navigation page, find the chart and open it.

2. At the top of the wizard interface, click .

3. In the window that opens, enable Access via link. DataLens automatically grants access to related objects.

   Warning

   You should materialize the dataset that the object is based on.

   If the data source is a ClickHouse DB in Yandex Cloud, then materialization is not required.

4. Copy the public link and click Apply.

Access management

You can configure chart permissions.

To configure chart permissions:

1. On the navigation page, find the chart that you want to change permissions for.
2. On the right side, click and select Configure access.
3. Enter the username in the Add participants field and click Select.
4. In the window that opens, select the permission type and click Add.

For more information about types of permissions, see Managing access to DataLens.

See also

• Creating a line chart
• Creating a pivot table
• Creating a table
• Creating an stacked area chart
• Creating a column chart
• Creating a bar chart
• Creating a pie chart
• Creating a map
• Creating a QL chart
• Publishing a chart