silverstripe-framework/docs/en/02_Developer_Guides/00_Model/08_SQL_Select.md

title: SQLSelect summary: Write and modify direct database queries through SQLSelect.

SQLSelect

A [api:SQLSelect] object represents a SQL query, which can be serialized into a SQL statement. Dealing with low-level SQL such as mysql_query() is not encouraged, since the ORM provides powerful abstraction API's.

For example, if you want to run a simple COUNT SQL statement, the following three statements are functionally equivalent:

:::php
// Through raw SQL.
$count = DB::query('SELECT COUNT(*) FROM "Member"')->value();

// Through SQLSelect abstraction layer.
$query = new SQLSelect();
$count = $query->setFrom('Member')->setSelect('COUNT(*)')->value();

// Through the ORM.
$count = Member::get()->count();

The SQLSelect object is used by the SilverStripe ORM internally. By understanding SQLSelect, you can modify the SQL that the ORM creates.

Usage

Select

:::php
$sqlQuery = new SQLSelect();
$sqlQuery->setFrom('Player');
$sqlQuery->selectField('FieldName', 'Name');
$sqlQuery->selectField('YEAR("Birthday")', 'Birthyear');
$sqlQuery->addLeftJoin('Team','"Player"."TeamID" = "Team"."ID"');
$sqlQuery->addWhere(array('YEAR("Birthday") = ?' => 1982));

// $sqlQuery->setOrderBy(...);
// $sqlQuery->setGroupBy(...);
// $sqlQuery->setHaving(...);
// $sqlQuery->setLimit(...);
// $sqlQuery->setDistinct(true);

// Get the raw SQL (optional)
$rawSQL = $sqlQuery->sql();

// Execute and return a Query object
$result = $sqlQuery->execute();

// Iterate over results
foreach($result as $row) {
	echo $row['BirthYear'];
}

The $result is an array lightly wrapped in a database-specific subclass of [api:Query]. This class implements the Iterator-interface, and provides convenience-methods for accessing the data.

Delete

:::php
$sqlQuery->setDelete(true);

Insert / Update

Currently not supported through the `SQLSelect` class, please use raw `DB::query()` calls instead.

:::php
DB::query('UPDATE "Player" SET "Status"=\'Active\'');

Joins

:::php
$sqlQuery = new SQLSelect();
$sqlQuery->setFrom('Player');
$sqlQuery->addSelect('COUNT("Player"."ID")');
$sqlQuery->addWhere(array('"Team"."ID" => 99));
$sqlQuery->addLeftJoin('Team', '"Team"."ID" = "Player"."TeamID"');

$count = $sqlQuery->execute()->value();

Mapping

Creates a map based on the first two columns of the query result.

:::php
$sqlQuery = new SQLSelect();
$sqlQuery->setFrom('Player');
$sqlQuery->setSelect('ID');
$sqlQuery->selectField('CONCAT("Name", ' - ', YEAR("Birthdate")', 'NameWithBirthyear');
$map = $sqlQuery->execute()->map();

echo $map;

// returns array(
// 	1 => "Foo - 1920",
//	2 => "Bar - 1936"
// );

Related Documentation

• Introduction to the Data Model and ORM

API Documentation

• [api:DataObject]
• [api:SQLSelect]
• [api:DB]
• [api:Query]
• [api:Database]