# QBGroupBy

## Overview

The `QBGroupBy` class is utilized to define SQL `GROUP BY` conditions within a `QBSelect` query. It allows adding columns, functions, or primary key columns to the `GROUP BY` clause. This class also provides the capability to clear the existing `GROUP BY` clause, ensuring flexibility in query construction.

**Key Features**

The `parent` property links the `QBGroupBy` instance to its parent table clause, which can be a query or a join clause. The `root` property provides access to the parent query builder, enabling hierarchical query manipulation.

The `add(column)` and `add(function)` methods enable adding columns or functions to the `GROUP BY` clause, supporting aggregation queries. The `addPk()` method simplifies grouping by adding primary key columns in alphabetical order. Additionally, the `clear()` method removes all conditions from the `GROUP BY` clause, allowing for dynamic query adjustments.

For further details on query construction and execution, refer to the [QBSelect](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbselect) section of the documentation.

## Properties Summarized

| Type                                                                                       | Name              | Summary                                                                      |
| ------------------------------------------------------------------------------------------ | ----------------- | ---------------------------------------------------------------------------- |
| [QBSelect](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbselect) | [parent](#parent) | Get query builder parent table clause, this may be a query or a join clause. |
| [QBSelect](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbselect) | [root](#root)     | Get query builder parent.                                                    |

## Methods Summarized

| Type                                                                                         | Name                       | Summary                                                                          |
| -------------------------------------------------------------------------------------------- | -------------------------- | -------------------------------------------------------------------------------- |
| [QBGroupBy](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbgroupby) | [add(column)](#add-column) | Add column name to group-by clause.                                              |
| [QBGroupBy](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbgroupby) | [addPk()](#addpk)          | Add the tables' primary pk columns in alphabetical order to the group by clause. |
| [QBGroupBy](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbgroupby) | [clear()](#clear)          | Clear the to group-by clause.                                                    |

## Properties Detailed

### parent

Get query builder parent table clause, this may be a query or a join clause.

**Type**\
[QBSelect](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbselect)

**Sample**

```js
var query = datasources.db.example_data.person.createSelect();
	query.where.add(query.joins.person_to_parent.joins.person_to_parent.columns.name.eq('john'))
	foundset.loadRecords(query)
```

### root

Get query builder parent.

**Type**\
[QBSelect](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbselect)

**Sample**

```js
var subquery = datasources.db.example_data.order_details.createSelect();

	var query = datasources.db.example_data.orders.createSelect();
	query.where.add(query
		.or
			.add(query.columns.order_id.not.isin([1, 2, 3]))

			.add(query.exists(
					subquery.where.add(subquery.columns.orderid.eq(query.columns.order_id)).root
			))
		)

	foundset.loadRecords(query)
```

## Methods Detailed

### add(column)

Add column name to group-by clause.

Same as query.groupBy().add(join.getColumn("value"))

**Parameters**

* [QBColumn](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbcolumn) **column** the column to add to the query condition

**Returns:** [QBGroupBy](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbgroupby) the updated group-by clause with the specified column added.

**Sample**

```js
var query = datasources.db.example_data.orders.createSelect();
query.groupBy.add(query.columns.orderid) // have to group by on pk when using having-conditions in (foundset) pk queries
.root.having.add(query.joins.orders_to_order_details.columns.quantity.count.eq(0))
foundset.loadRecords(query)
```

### addPk()

Add the tables' primary pk columns in alphabetical order to the group by clause.

**Returns:** [QBGroupBy](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbgroupby) the updated group-by clause with the primary key(s) of the table added.

**Sample**

```js
var query = datasources.db.example_data.orders.createSelect();
query.groupBy.addPk() // have to group by on pk when using having-conditions in (foundset) pk queries
.root.having.add(query.joins.orders_to_order_details.columns.quantity.count.eq(0))
foundset.loadRecords(query)
```

### clear()

Clear the to group-by clause.

**Returns:** [QBGroupBy](https://docs.servoy.com/reference/servoycore/dev-api/database-manager/qbgroupby) the cleared group-by clause.

**Sample**

```js
var q = foundset.getQuery()
q.where.add(q.columns.x.eq(100))
query.groupBy.clear.root.clearHaving()
foundset.loadRecords(q);
```

***