---
title: "Using and Developing Query Managers"
manual: "SAV Charts"
version: "14.7"
source: "Tutorial/ParsersTutorial/UsingAndDevelopingQueryManagers/Index.rst"
rendered: "2026-09-17T13:01:15+00:00"
---

# Using and Developing Query Managers {#using-and-developing-query-managers}

Query managers are used in \<query> tags to execute
queries that can be used in charts.

The SAV Charts extension comes with an internal query
manager named `savcharts` that can
handle TYPO3 database queries as well as queries
from other databases.

## Using the Query Manager {#using-the-query-manager}

In the backend in `Records` mode create a new record
in a page or a folder.

![](../../../Images/Tutorial/InternalQueryManager.png)

Select `Database` if you need to access to an external database,
fill the different fields and save.

> [!TIP]
> You do not need to create a new database access if you only need
> to access to the current TYPO3 database.

Select `Query` to create a query. Select a database (default is
`TYPO3 Database`), fill the different clauses and save.

The following configuration is an example of how to obtain the
number of pages created per year.

-   In SELECT clause field

    ```sql
    COUNT(*) AS Count,
    YEAR(FROM_UNIXTIME(crdate)) AS Year
    ```
-   In FROM clause field

    ```sql
    pages
    ```
-   In WHERE clause field

    ```sql
    NOT deleted AND NOT hidden
    ```
-   In GROUP BY clause field

    ```sql
    year
    ```

The following query is generated by this configuration.

```sql
SELECT
    COUNT(*) AS Count,
    YEAR(FROM_UNIXTIME(crdate)) AS Year
FROM
    pages
WHERE
    NOT deleted AND NOT hidden
GROUP BY
    Year
```

If the new query has ID 1, the following FlexForm
configurations will display a bar chart showing
the number of pages per year.

> [!IMPORTANT]
> The flag `Allow queries (Admin)` must be set by an Admin user in the content
> Flexform to execute queries.

-   In the Markers Flexform field

    **Fluid Parser**

    ```xml
    <c:marker id="title">Analysis of the site</c:marker>
    <c:marker id="labelSet0">Pages per year</c:marker>
    ```

    **XML Parser**

    ```xml
    <marker id="title">Analysis of the site</marker>
    <marker id="labelSet0">Pages per year</marker>
    ```
-   In the Queries Flexform field

    **Fluid Parser**

    ```xml
    <c:query id="1"  manager="savcharts" uid="1" />
    ```

    **XML Parser**

    ```xml
    <query id="1">
        <setQueryManager name="savcharts" uid="1" />
    </query>
    ```
-   In the Data Flexform field

    **Fluid Parser**

    ```xml
    <c:data id="labels" values="{query__1.Year}" />

    <c:data id="data">
      <c:item key="0" value="{query__1.Count}" />
    </c:data>
    ```

    **XML Parser**

    ```xml
    <data id="data0" >
      <setDataFromQuery query="1" field="Count" />
    </data>
    <data id="labels" >
      <setDataFromQuery query="1" field="Year" />
    </data>
    <data id="data">
      <item key="0" value="data#data0" />
    </data>
    ```
-   In the Templates Flexform field

    **Fluid Parser**

    ```xml
    <c:template id="1">
        EXT:sav_charts/Resources/Private/Templates/ChartsExamples/FluidParser/BarChartAdvanced.fluid
    </c:template>
    ```

    **XML Parser**

    ```xml
    <template id="1">
        EXT:sav_charts/Resources/Private/Templates/ChartsExamples/BarChartAdvanced.xml
    </template>
    ```

The default query manager, savcharts, is used
in the `Queries` section. It calls the query
with the UID 1.

The Data section of the FlexForm overloads
the template to display a single bar chart
with data from the query, as explained
in [Using Advanced Templates](../UsingAdvancedTemplates/Index.html#usingAdvancedTemplates).

Go to the front-end to view the resulting chart.

![](../../../Images/Tutorial/barChartWithQueryInFrontEnd.png)

## Using Markers in Queries {#using-markers-in-queries}

Markers can be used in queries. For example,
assume that the previous query should return
the number of pages created between the
years `yearMin` and `yearMax`.

First, insert the syntax `###marker###` into
the WHERE clause of the previous content element
in the query.

```sql
NOT deleted AND NOT hidden AND YEAR(FROM_UNIXTIME(crdate)) BETWEEN ###yearMin### AND ###yearMax###
```

Add markers to the Flexform field of your chart,
then save and go to the front-end.

**Fluid Parser**

```xml
<c:marker id="title">Analysis of the site</c:marker>
<c:marker id="labelSet0">Pages per year</c:marker>

<c:marker id="yearMin">2010</c:marker>
<c:marker id="yearMax">2020</c:marker>
```

**XML Parser**

```xml
<marker id="title">Analysis of the site</marker>
<marker id="labelSet0">Pages per year</marker>

<marker id="yearMin">2010</marker>
<marker id="yearMax">2020</marker>
```

![](../../../Images/Tutorial/barChartWithQueryAndMarkersInFrontEnd.png)

You can also introduce markers in TypoScript.
For example, add the following TypoScript to
your page to modify only the value of the
`###yearMin###` marker, then clear the cache and
go to the front-end. The syntax `customQuery.1` refers
to the query with the UID of 1.

```typoscript
plugin.tx_savcharts.settings.customQuery.1 {
  yearMin = TEXT
  yearMin.value = 2009
}
```

![](../../../Images/Tutorial/barChartWithQueryAndTyposcriptMarkersInFrontEnd.png)

## Developing Your Query Manager {#developing-your-query-manager}

Query managers are implemented by means of hooks.The hook for the internal query manager
is in `Classes/Hooks/SavChartsQueryManager.php`. This class extends the abstract class
AbstractQueryManager (`Classes/Hooks/AbstractQueryManager.php`)
which itself implements the interface QueryManagerInterface
(`Classes/Hooks/QueryManagerInterface.php`).

You can develop your own query manager by providing a hook which must
be added in the file `ext_localconf.php`
of your extension.

Assuming that your vendor name is `MyVendorName` and your extension
name is `my_extension`. Assuming also
that you have written your manager as the class MyQueryManager
in `Classes/Hooks/MyQueryManager.php`.
Finally, assuming that you want to name your query manager `myManager`, you should add
the following code in `ext_localconf.php` of your extension.

```php
$TYPO3_CONF_VARS['EXTCONF'][$_EXTKEY]['queryManagerClass']['myManager'] = \MyVendorName\MyExtension\Hooks\MyQueryManager::class;
```