> Starting from Grafana v5.1 you can name the time column _time_ in addition to earlier supported _time_sec_. Usage of _time_sec_ will eventually be deprecated.
Grafana ships with a built-in MySQL data source plugin that allows you to query and visualize data from a MySQL compatible database like MariaDB or Percona Server.
| **Name** | The data source name. This is how you refer to the data source in panels and queries. |
| **Default** | Default data source means that it will be pre-selected for new panels. |
| **Host** | The IP address/hostname and optional port of your MySQL instance. |
| **Database** | Name of your MySQL database. |
| **User** | Database user's login/username |
| **Password** | Database user's password |
| **Session Timezone** | Specifies the time zone used in the database session, such as `Europe/Berlin` or `+02:00`. Required if the timezone of the database (or the host of the database) is set to something other than UTC. Set the value used in the session with `SET time_zone='...'`. If you leave this field empty, then the time zone is not updated. For more information, refer to the [MySQL documentation](https://dev.mysql.com/doc/en/time-zone-support.html). |
| **Max open** | The maximum number of open connections to the database, default `100` (Grafana v5.4+). |
| **Max idle** | The maximum number of connections in the idle connection pool, default `100` (Grafana v5.4+). |
| **Auto (max idle)** | Toggle to set the maximum number of idle connections to the number of maximum open connections (available in Grafana v9.5.1+). Default is `true`. |
| **Allow cleartext passwords** | Allows the use of the [cleartext client side plugin](https://dev.mysql.com/doc/en/cleartext-pluggable-authentication.html) as required by a specific type of account, such as one defined with the [PAM authentication plugin](https://dev.mysql.com/doc/en/pam-pluggable-authentication.html). <br/>**Sending passwords in clear text may be a security problem in some configurations**. To avoid password issues, it is recommended that clients connect to a MySQL server using a method that protects the password. Possibilities include [TLS / SSL](https://github.com/go-sql-driver/mysql#tls), IPsec, or a private network. Default is `false`. |
| **Max lifetime** | The maximum amount of time in seconds a connection may be reused. This should always be lower than configured [wait_timeout](https://dev.mysql.com/doc/en/server-system-variables.html#sysvar_wait_timeout) in MySQL (Grafana v5.4+). The default is `14400` or 4 hours. |
The **Min time interval** setting defines a lower limit for the [`$__interval`][add-template-variables-interval] and [`$__interval_ms`][add-template-variables-interval-ms] variables.
If your table or database name contains a reserved word or a [prohibited character](https://dev.mysql.com/doc/en/identifiers.html) the editor will put quotes around the name. For example, the name `table-name` will be quoted with backticks - `` `table-name` ``.
**Note:** If a default database has been configured through the Data Source Configuration page (or through a provisioning configuration file), the user will only be able to use that single preconfigured database for querying.
Use the first dropdown to choose whether all of the filters need to match (`AND`), or if only one of the filters needs to match (`OR`).
Use the second dropdown to choose a filter.
To filter on more columns, click the plus (`+`) button to the right of the condition dropdown.
To remove a filter, click the `x` button next to that filter's dropdown.
After selecting a date type column, you can choose Macros from the operators list and select timeFilter which will add the $\_\_timeFilter macro to the query with the selected date column.
To group the results by column, flip the group switch at the top of the editor. You can then choose which column to group the results by. The group by clause can be removed by pressing the X button.
To make advanced queries, switch to the code editor by clicking `code` in the top right corner of the editor. The code editor support autocompletion of tables, columns, SQL keywords, standard sql functions, Grafana template variables and Grafana macros. Columns cannot be completed before a table has been specified.
| `$__time(dateColumn)` | Will be replaced by an expression to convert to a UNIX timestamp and rename the column to `time_sec`. For example, _UNIX_TIMESTAMP(dateColumn) as time_sec_ |
| `$__timeEpoch(dateColumn)` | Will be replaced by an expression to convert to a UNIX timestamp and rename the column to `time_sec`. For example, _UNIX_TIMESTAMP(dateColumn) as time_sec_ |
| `$__timeFilter(dateColumn)` | Will be replaced by a time range filter using the specified column name. For example, _dateColumn BETWEEN FROM_UNIXTIME(1494410783) AND FROM_UNIXTIME(1494410983)_ |
| `$__timeFrom()` | Will be replaced by the start of the currently active time selection. For example, _FROM_UNIXTIME(1494410783)_ |
| `$__timeTo()` | Will be replaced by the end of the currently active time selection. For example, _FROM_UNIXTIME(1494410983)_ |
| `$__timeGroup(dateColumn,'5m')` | Will be replaced by an expression usable in GROUP BY clause. For example, *cast(cast(UNIX_TIMESTAMP(dateColumn)/(300) as signed)*300 as signed),\* |
| `$__timeGroup(dateColumn,'5m', 0)` | Same as above but with a fill parameter so missing points in that series will be added by grafana and 0 will be used as value. |
| `$__timeGroup(dateColumn,'5m', NULL)` | Same as above but NULL will be used as value for missing points. |
| `$__timeGroup(dateColumn,'5m', previous)` | Same as above but the previous value in that series will be used as fill value if no value has been seen yet NULL will be used (only available in Grafana 5.3+). |
| `$__timeGroupAlias(dateColumn,'5m')` | Will be replaced identical to $\_\_timeGroup but with an added column alias (only available in Grafana 5.3+). |
| `$__unixEpochFilter(dateColumn)` | Will be replaced by a time range filter using the specified column name with times represented as Unix timestamp. For example, _dateColumn > 1494410783 AND dateColumn < 1494497183_ |
| `$__unixEpochFrom()` | Will be replaced by the start of the currently active time selection as Unix timestamp. For example, _1494410783_ |
| `$__unixEpochTo()` | Will be replaced by the end of the currently active time selection as Unix timestamp. For example, _1494497183_ |
| `$__unixEpochNanoFilter(dateColumn)` | Will be replaced by a time range filter using the specified column name with times represented as nanosecond timestamp. For example, _dateColumn > 1494410783152415214 AND dateColumn < 1494497183142514872_ |
| `$__unixEpochNanoFrom()` | Will be replaced by the start of the currently active time selection as nanosecond timestamp. For example, _1494410783152415214_ |
| `$__unixEpochNanoTo()` | Will be replaced by the end of the currently active time selection as nanosecond timestamp. For example, _1494497183142514872_ |
| `$__unixEpochGroup(dateColumn,'5m', [fillmode])` | Same as $\_\_timeGroup but for times stored as Unix timestamp (only available in Grafana 5.3+). |
| `$__unixEpochGroupAlias(dateColumn,'5m', [fillmode])` | Same as above but also adds a column alias (only available in Grafana 5.3+). |
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 shows up after a query has 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 and rows your query returns.
If the `Format as` query option is set to `Time Series` then the query must have a column named time that returns either a SQL datetime or any numeric datatype representing Unix epoch in seconds. In addition, result sets of time series queries must be sorted by time for panels to properly visualize the result.
A time series query result is returned in a [wide data frame format](https://grafana.com/developers/plugin-tools/introduction/data-frames#wide-format). Any column except time or of type string transforms into value fields in the data frame query result. Any string column transforms into field labels in the data frame query result.
> For backward compatibility, there's an exception to the above rule for queries that return three columns including a string column named metric. Instead of transforming the metric column into field labels, it becomes the field name, and then the series name is formatted as the value of the metric column. See the example with the metric column below.
Given the data frame result in the following example and using the graph panel, you will get two series named _value 10.0.1.1_ and _value 10.0.1.2_. To render the series with a name of _10.0.1.1_ and _10.0.1.2_ , use a [Standard options definitions][configure-standard-options-display-name] display value of `${__field.labels.hostname}`.
Instead of hard-coding things like server, application and sensor name in your metric queries you can use variables in their place. Variables are shown as dropdown select boxes at the top of the dashboard. These dropdowns make it easy to change the data being displayed in your dashboard.
For example, you can have a variable that contains all values for the `hostname` column in a table if you specify a query like this in the templating variable _Query_ setting.
A query can return multiple columns and Grafana will automatically create a list from them. For example, the query below will return a list with values from `hostname` and `hostname2`.
To use time range dependent macros like `$__timeFilter(column)` in your query the refresh mode of the template variable needs to be set to _On Time Range Change_.
Another option is a query that can create a key/value variable. The query should return two columns that are named `__text` and `__value`. The `__text` column value should be unique (if it is not unique then the first value is used). The options in the dropdown will have a text and value that allows you to have a friendly name as text and an id as the value. An example query with `hostname` as the text and `id` as the value:
```sql
SELECT hostname AS __text, id AS __value FROM my_host
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)
> Important that you surround the `__searchFilter` expression with quotes as Grafana does not do this for you.
The example below shows how to use `__searchFilter` as part of the query field to enable searching for `hostname` while the user types in the dropdown select box.
From Grafana 4.3.0 to 4.6.0, template variables are always quoted automatically so if it is a string value do not wrap them in quotes in where clauses.
From Grafana 4.7.0, template variable values are only quoted when the template variable is a `multi-value`.
If the variable is a multi-value variable then use the `IN` comparison operator rather than `=` to match against multiple values.
Grafana automatically creates a quoted, comma-separated string for multi-value variables. For example: if `server01` and `server02` are selected then it will be formatted as: `'server01', 'server02'`. To disable quoting, use the csv formatting option for variables:
[Annotations][annotate-visualizations] allow you to overlay rich event information on top of graphs. You add annotation queries via the Dashboard menu / Annotations view.
