*$__timeFilter(dateColumn)* | Will be replaced by a time range filter using the specified column name. For example, *dateColumn > FROM_UNIXTIME(1494410783) AND dateColumn < FROM_UNIXTIME(1494497183)*
We plan to add many more macros. If you have suggestions for what macros you would like to see, please [open an issue](https://github.com/grafana/grafana) in our GitHub repo.
The query editor has a link named `Generated SQL` that show up after a query as been executed, while in panel edit mode. Click on it and it will expand and show the raw interpolated SQL string that was executed.
If the `Format as` query option is set to `Table` then you can basically do any type of SQL query. The table panel will automatically show the results of whatever columns & rows your query returns.
Query editor with example query:
The query:
```sql
SELECT
title as 'Title',
user.login as 'Created By' ,
dashboard.created as 'Created On'
FROM dashboard
INNER JOIN user on user.id = dashboard.created_by
WHERE $__timeFilter(dashboard.created)
```
You can control the name of the Table panel columns by using regular `as ` SQL column selection syntax.
The resulting table panel:
### Time series queries
If you set `Format as` to `Time series`, for use in Graph panel for example, then there are some requirements for
what your query returns.
- Must be a column named `time_sec` representing a unix epoch in seconds.
- Must be a column named `value` representing the time series value.
- Must be a column named `metric` representing the time series name.
Example:
```sql
SELECT
min(UNIX_TIMESTAMP(time_date_time)) as time_sec,
max(value_double) as value,
metric1 as metric
FROM test_data
WHERE $__timeFilter(time_date_time)
GROUP BY metric1, UNIX_TIMESTAMP(time_date_time) DIV 300
ORDER BY time_sec asc
```
Currently, there is no support for a dynamic group by time based on time range & panel width.
Instead of hard-coding things like server, application and sensor name in you metric queries you can use variables in their place. Variables are shown as dropdown select boxes at the top of the dashboard. These dropdowns makes it easy to change the data being displayed in your dashboard.
Checkout the [Templating]({{< relref "reference/templating.md" >}}) documentation for an introduction to the templating feature and the different types of template variables.
### Query Variable
If you add a template variable of the type `Query`, you can write a MySQL query that can
return things like measurement names, key names or key values that are shown as a dropdown select box.
For example, you can have a variable that contains all values for the `hostname` column in a table if you specify a query like this in the templating variable *Query* setting.
```sql
SELECT hostname FROM my_host
```
A query can returns multiple columns and Grafana will automatically create a list from them. For example, the query below will return a list with values from `hostname` and `hostname2`.
```sql
SELECT my_host.hostname, my_other_host.hostname2 FROM my_host JOIN my_other_host ON my_host.city = my_other_host.city
```
You can also create nested variables. For example if you had another variable named `region`. Then you could have
the hosts variable only show hosts from the current selected region with a query like this (if `region` is a multi-value variable then use the `IN` comparison operator rather than `=` to match against multiple values):
```sql
SELECT hostname FROM my_host WHERE region IN($region)
```
### Using Variables in Queries
Template variables are quoted automatically so if it is a string value do not wrap them in quotes in where clauses. If the variable is a multi-value variable then use the `IN` comparison operator rather than `=` to match against multiple values.
There are two syntaxes:
`$<varname>` Example with a template variable named `hostname`:
```sql
SELECT
UNIX_TIMESTAMP(atimestamp) as time_sec,
aint as value,
avarchar as metric
FROM my_table
WHERE $__timeFilter(atimestamp) and hostname in($hostname)
ORDER BY atimestamp ASC
```
`[[varname]]` Example with a template variable named `hostname`:
```sql
SELECT
UNIX_TIMESTAMP(atimestamp) as time_sec,
aint as value,
avarchar as metric
FROM my_table
WHERE $__timeFilter(atimestamp) and hostname in([[hostname]])
