#Use context variables

With context variables, you can reuse information from the current page, user, time, and filter inputs to render charts and enable linkage based on context.

#Applicable scope

• Data query in Builder mode: select variables for filter conditions.

• Data query in SQL mode: choose variables and insert expressions (for example, {{ ctx.user.id }}).

• Chart options in Custom mode: write JS expressions directly.

• Interaction events (for example, click to open a drill‑down dialog and pass data): write JS expressions directly.

Note:

• Do not wrap {{ ... }} with single or double quotes; binding is handled safely based on variable type (string, number, time, NULL).
• When a variable is NULL or undefined, handle nulls explicitly in SQL using COALESCE(...) or IS NULL.