mirror of
https://github.com/grafana/grafana.git
synced 2025-09-17 17:52:57 +08:00
0cc636665a
* created config doc * updated the config doc * updates to the configure doc * updates to configure doc * updated the templates doc * more query editor edits * final edit on templates doc * final query editor edits and new screenshots * added tables to configure * final edits * final edits * final edits * added admonition and updates based on feedback * ran prettier
131 lines
4.9 KiB
Markdown
131 lines
4.9 KiB
Markdown
---
|
|
aliases:
|
|
- ../../data-sources/mssql/template-variables/
|
|
description: Using template variables with Microsoft SQL Server in Grafana
|
|
keywords:
|
|
- grafana
|
|
- MSSQL
|
|
- Microsoft
|
|
- SQL
|
|
- Azure SQL Database
|
|
- templates
|
|
- variables
|
|
- queries
|
|
labels:
|
|
products:
|
|
- cloud
|
|
- enterprise
|
|
- oss
|
|
menuTitle: Template variables
|
|
title: Microsoft SQL Server template variables
|
|
weight: 400
|
|
refs:
|
|
variables:
|
|
- pattern: /docs/grafana/
|
|
destination: /docs/grafana/<GRAFANA_VERSION>/dashboards/variables/
|
|
- pattern: /docs/grafana-cloud/
|
|
destination: /docs/grafana/<GRAFANA_VERSION>/dashboards/variables/
|
|
variable-syntax-advanced-variable-format-options:
|
|
- pattern: /docs/grafana/
|
|
destination: /docs/grafana/<GRAFANA_VERSION>/dashboards/variables/variable-syntax/#advanced-variable-format-options
|
|
- pattern: /docs/grafana-cloud/
|
|
destination: /docs/grafana/<GRAFANA_VERSION>/dashboards/variables/variable-syntax/#advanced-variable-format-options
|
|
add-template-variables:
|
|
- pattern: /docs/grafana/
|
|
destination: /docs/grafana/<GRAFANA_VERSION>/dashboards/variables/add-template-variables/
|
|
- pattern: /docs/grafana-cloud/
|
|
destination: /docs/grafana/<GRAFANA_VERSION>/dashboards/variables/add-template-variables/
|
|
---
|
|
|
|
# Microsoft SQL Server template variables
|
|
|
|
Instead of hard-coding details such as server, application, and sensor names in metric queries, you can use variables.
|
|
Grafana displays these variables in drop-down select boxes at the top of the dashboard to help you change the data displayed in your dashboard.
|
|
Grafana refers to such variables as **template variables**.
|
|
|
|
For general information on using variables in Grafana, refer to [Add variables](ref:add-template-variables).
|
|
|
|
For an introduction to templating and template variables, refer to [Templating](ref:variables) and [Add and manage variables](ref:add-template-variables).
|
|
|
|
## Query variable
|
|
|
|
A query variable in Grafana dynamically retrieves values from your data source using a query. With a query variable, you can write a SQL query that returns values such as measurement names, key names, or key values that are shown in a drop-down select box.
|
|
|
|
For example, the following query returns all values from the `hostname` column:
|
|
|
|
```sql
|
|
SELECT hostname FROM host
|
|
```
|
|
|
|
A query can return multiple columns, and Grafana automatically generates a list using the values from those columns. For example, the following query returns values from both the `hostname` and `hostname2` columns, which are included in the variable's drop-down list.
|
|
|
|
```sql
|
|
SELECT [host].[hostname], [other_host].[hostname2] FROM host JOIN other_host ON [host].[city] = [other_host].[city]
|
|
```
|
|
|
|
You can also create a key/value variable using a query that returns two columns named `__text` and `__value`.
|
|
|
|
- The `__text` column defines the label shown in the drop-down.
|
|
|
|
- The `__value` column defines the value passed to panel queries.
|
|
|
|
This is useful when you want to display a user-friendly label (like a hostname) but use a different underlying value (like an ID).
|
|
|
|
Note that the values in the `_text` column should be unique. If there are duplicates, Grafana uses only the first matching entry.
|
|
|
|
```sql
|
|
SELECT hostname __text, id __value FROM host
|
|
```
|
|
|
|
You can also create nested variables, where one variable depends on the value of another. For example, if you have a variable named `region`, you can configure a `hosts` variable to only show hosts from the selected region. If `region` is a multi-value variable, use the `IN` operator instead of `=` to match against multiple selected values.
|
|
|
|
```sql
|
|
SELECT hostname FROM host WHERE region IN ($region)
|
|
```
|
|
|
|
## Use variables in queries
|
|
|
|
Grafana automatically quotes template variable values only when the template variable is a `multi-value`.
|
|
|
|
When using a multi-value variable, use the `IN` comparison operator instead of `=` to match against multiple values.
|
|
|
|
Grafana supports two syntaxes for using variables in queries:
|
|
|
|
- **`$<varname>` syntax**
|
|
|
|
Example with a template variable named `hostname`:
|
|
|
|
```sql
|
|
SELECT
|
|
atimestamp time,
|
|
aint value
|
|
FROM table
|
|
WHERE $__timeFilter(atimestamp) and hostname in($hostname)
|
|
ORDER BY atimestamp
|
|
```
|
|
|
|
- **`[[varname]]` syntax**
|
|
|
|
Example with a template variable named `hostname`:
|
|
|
|
```sql
|
|
SELECT
|
|
atimestamp as time,
|
|
aint as value
|
|
FROM table
|
|
WHERE $__timeFilter(atimestamp) and hostname in([[hostname]])
|
|
ORDER BY atimestamp
|
|
```
|
|
|
|
### Disable quoting for multi-value variables
|
|
|
|
By default, Grafana formats multi-value variables as a quoted, comma-separated string. For example, if `server01` and `server02` are selected, the result will be `'server01'`, `'server02'`. To disable quoting, use the `csv` formatting option for variables:
|
|
|
|
```text
|
|
${servers:csv}
|
|
```
|
|
|
|
This outputs the values as an unquoted comma-separated list.
|
|
|
|
Refer to [Advanced variable format options](ref:variable-syntax-advanced-variable-format-options) for additional information.
|