Oracle template variables

Use template variables to create dynamic, reusable dashboards. Instead of hard-coding details such as server names, applications, or regions in your queries, you can use variables that appear as drop-down selectors at the top of the dashboard.

Before you begin

Configure the Oracle data source.
Understand Grafana template variables.

Supported variable types

Variable type	Supported
Query	Yes
Custom	Yes
Data source	Yes
Interval	Yes

Create a query variable

To create a query variable:

Navigate to Dashboard settings > Variables.
Click Add variable.
Select Query as the variable type.
Select the Oracle data source.
Enter a SQL query that returns the values you want as variable options.

For detailed instructions, refer to Add a query variable.

Query examples

An Oracle variable query returns column values that populate the variable drop-down.

Single column

Return all values from a single column:

SELECT hostname FROM host

Multiple columns

A query can return multiple columns. Grafana creates a combined list from all returned columns:

SELECT host.hostname, other_host.hostname2
FROM host
JOIN other_host ON host.city = other_host.city

Key/value variables

Return two columns named __text and __value to create a variable where the display name differs from the stored value. The __text column values must be unique:

SELECT hostname AS __text, id AS __value
FROM host

Time-dependent variables

To use time range macros like $__timeFilter(column) in your variable query, set the variable refresh to On Time Range Change:

SELECT event_name
FROM event_log
WHERE $__timeFilter(time_column)

Chained variables

Create nested variables by referencing one variable inside another. For example, create a region variable, then use it to filter a hosts variable:

SELECT hostname
FROM host
WHERE region = '$region'

Use variables in queries

Reference variables in your Oracle queries using the $variable or ${variable} syntax.

Multi-value variables

If a variable allows multiple selections, use the IN operator instead of =:

SELECT *
FROM host
WHERE hostname IN ($hostname)

Grafana interpolates multi-value variables as single-quoted, comma-separated values (for example, 'host1','host2','host3').

Interval variables

Use an interval variable to let users control the time-grouping granularity of a query. Reference the variable inside a time-grouping macro:

SELECT
  $__timeGroup(sample_time, '$interval') AS time,
  AVG(cpu_percent) AS value
FROM system_metrics
WHERE $__timeFilter(sample_time)
GROUP BY $__timeGroup(sample_time, '$interval')
ORDER BY time

Grafana’s built-in $__interval variable works the same way and adjusts the grouping automatically based on the panel’s time range and width.