diff --git a/docs/sources/dashboards/variables/add-template-variables/index.md b/docs/sources/dashboards/variables/add-template-variables/index.md index 21ae42d1e56..ee2e77bace2 100644 --- a/docs/sources/dashboards/variables/add-template-variables/index.md +++ b/docs/sources/dashboards/variables/add-template-variables/index.md @@ -135,9 +135,12 @@ Query expressions are different for each data source. For more information, refe - **On Dashboard Load:** Queries the data source every time the dashboard loads. This slows down dashboard loading, because the variable query needs to be completed before dashboard can be initialized. - **On Time Range Change:** Queries the data source every time the dashboard loads and when the dashboard time range changes. Use this option if your variable options query contains a time range filter or is dependent on the dashboard time range. 1. In the **Query** field, enter a query. + - The query field varies according to your data source. Some data sources have custom query editors. - - Make sure that the query returns values named `__text` and `__value` as appropriate in your query syntax. For example, in SQL, you can use a query such as `SELECT hostname AS __text, id AS __value FROM MyTable`. Queries for other languages will vary depending on syntax. + - Each data source defines how the variable values are extracted. The typical implementation uses every string value returned from the data source response as a variable value. Make sure to double-check the documentation for the data source. + - Some data sources let you provide custom "display names" for the values. For instance, the PostgreSQL, MySQL, and Microsoft SQL Server plugins handle this by looking for fields named `__text` and `__value` in the result. Other data sources may look for `text` and `value` or use a different approach. Always remember to double-check the documentation for the data source. - If you need more room in a single input field query editor, then hover your cursor over the lines in the lower right corner of the field and drag downward to expand. + 1. (Optional) In the **Regex** field, type a regex expression to filter or capture specific parts of the names returned by your data source query. To see examples, refer to [Filter variables with regex](#filter-variables-with-regex). 1. In the **Sort** list, select the sort order for values to be displayed in the dropdown list. The default option, **Disabled**, means that the order of options returned by your data source query will be used. 1. (Optional) Enter [Selection Options](#configure-variable-selection-options).