silverstripe-framework/core/model/DataQuery.php
Sam Minnee de1494e3a8 ENHANCEMENT: Implemented DataList as the successor of DataObjectSet. DataList doesn't execute the query until it's actually needed, allowing for a more flexible ORM.
API CHANGE: augmentSQL is now passed a DataQuery object from which query parameters can be extracted.
API CHANGE: DataObjectDecorators that manipulate the query can now define augmentDataQueryCreation().
API CHANGE: The container class argument for DataObject::get() is deprecated.
API CHANGE: DataObject::buildSQL() and DataObject::extendedSQL() are deprecated; just use DataObject::get() now.
API CHANGE: DataObject::instance_get() and DataObject::instance_get_one() are deprecated, and can no longer be overloaded.
API CHANGE: DataObject::buildDataObjectSet() is deprecated.
API CHANGE: Cant't call manual manipulation methods on DataList such as insertFirst()
2011-05-01 15:25:45 +12:00

428 lines
11 KiB
PHP

<?php
/**
* An object representing a query of data from the DataObject's supporting database.
* Acts as a wrapper over {@link SQLQuery} and performs all of the query generation.
* Used extensively by DataList.
*/
class DataQuery {
protected $dataClass;
protected $query;
protected $collidingFields = array();
private $queryFinalised = false;
// TODO: replace subclass_access with this
protected $querySubclasses = true;
// TODO: replace restrictclasses with this
protected $filterByClassName = true;
/**
* Create a new DataQuery.
* @param $dataClass The name of the DataObject class that you wish to query
*/
function __construct($dataClass) {
$this->dataClass = $dataClass;
$this->initialiseQuery();
}
/**
* Clone this object
*/
function __clone() {
$this->query = clone $this->query;
}
/**
* Return the {@link DataObject} class that is being queried.
*/
function dataClass() {
return $this->dataClass;
}
/**
* Return the {@link SQLQuery} object that represents the current query; note that it will
* be a clone of the object.
*/
function query() {
return $this->getFinalisedQuery();
}
/**
* Remove a filter from the query
*/
function removeFilterOn($fieldExpression) {
$matched = false;
foreach($this->query->where as $i=>$item) {
if(strpos($item, $fieldExpression) !== false) {
unset($this->query->where[$i]);
$matched = true;
}
}
if(!$matched) user_error("Couldn't find $fieldExpression in the query filter.", E_USER_WARNING);
return $this;
}
/**
* Set up the simplest intial query
*/
function initialiseQuery() {
// Get the tables to join to
$tableClasses = ClassInfo::dataClassesFor($this->dataClass);
// Error checking
if(!$tableClasses) {
if(!ManifestBuilder::has_been_included()) {
user_error("DataObjects have been requested before the manifest is loaded. Please ensure you are not querying the database in _config.php.", E_USER_ERROR);
} else {
user_error("DataObject::buildSQL: Can't find data classes (classes linked to tables) for $this->dataClass. Please ensure you run dev/build after creating a new DataObject.", E_USER_ERROR);
}
}
$baseClass = array_shift($tableClasses);
$select = array("\"$baseClass\".*");
// Build our intial query
$this->query = new SQLQuery(array());
$this->query->distinct = true;
if($sort = singleton($this->dataClass)->stat('default_sort')) {
$this->sort($sort);
}
$this->query->from("\"$baseClass\"");
$this->selectAllFromTable($this->query, $baseClass);
singleton($this->dataClass)->extend('augmentDataQueryCreation', $this->query, $this);
}
/**
* Ensure that the query is ready to execute.
*/
function getFinalisedQuery() {
$query = clone $this->query;
// Get the tables to join to
$tableClasses = ClassInfo::dataClassesFor($this->dataClass);
$baseClass = array_shift($tableClasses);
$collidingFields = array();
// Join all the tables
if($this->querySubclasses) {
foreach($tableClasses as $tableClass) {
$query->leftJoin($tableClass, "\"$tableClass\".\"ID\" = \"$baseClass\".\"ID\"") ;
$this->selectAllFromTable($query, $tableClass);
}
}
// Resolve colliding fields
if($this->collidingFields) {
foreach($this->collidingFields as $k => $collisions) {
$caseClauses = array();
foreach($collisions as $collision) {
if(preg_match('/^"([^"]+)"/', $collision, $matches)) {
$collisionBase = $matches[1];
$collisionClasses = ClassInfo::subclassesFor($collisionBase);
$caseClauses[] = "WHEN \"$baseClass\".\"ClassName\" IN ('"
. implode("', '", $collisionClasses) . "') THEN $collision";
} else {
user_error("Bad collision item '$collision'", E_USER_WARNING);
}
}
$query->select[$k] = "CASE " . implode( " ", $caseClauses) . " ELSE NULL END"
. " AS \"$k\"";
}
}
if($this->filterByClassName) {
// If querying the base class, don't bother filtering on class name
if($this->dataClass != $baseClass) {
// Get the ClassName values to filter to
$classNames = ClassInfo::subclassesFor($this->dataClass);
if(!$classNames) user_error("DataObject::get() Can't find data sub-classes for '$callerClass'");
$query->where[] = "\"$baseClass\".\"ClassName\" IN ('" . implode("','", $classNames) . "')";
}
}
$query->select[] = "\"$baseClass\".\"ID\"";
$query->select[] = "CASE WHEN \"$baseClass\".\"ClassName\" IS NOT NULL THEN \"$baseClass\".\"ClassName\" ELSE '$baseClass' END AS \"RecordClassName\"";
// TODO: Versioned, Translatable, SiteTreeSubsites, etc, could probably be better implemented as subclasses of DataQuery
singleton($this->dataClass)->extend('augmentSQL', $query, $this);
return $query;
}
/**
* Execute the query and return the result as {@link Query} object.
*/
function execute() {
return $this->getFinalisedQuery()->execute();
}
/**
* Return this query's SQL
*/
function sql() {
return $this->getFinalisedQuery()->sql();
}
/**
* Return the number of records in this query.
* Note that this will issue a separate SELECT COUNT() query.
*/
function count() {
$baseClass = ClassInfo::baseDataClass($this->dataClass);
return $this->getFinalisedQuery()->count("DISTINCT \"$baseClass\".\"ID\"");
}
/**
* Return the maximum value of the given field in this DataList
*/
function Max($field) {
return $this->getFinalisedQuery()->aggregate("MAX(\"$field\")")->execute()->value();
}
/**
* Return the minimum value of the given field in this DataList
*/
function Min($field) {
return $this->getFinalisedQuery()->aggregate("MIN(\"$field\")")->execute()->value();
}
/**
* Return the average value of the given field in this DataList
*/
function Avg($field) {
return $this->getFinalisedQuery()->aggregate("AVG(\"$field\")")->execute()->value();
}
/**
* Return the sum of the values of the given field in this DataList
*/
function Sum($field) {
return $this->getFinalisedQuery()->aggregate("SUM(\"$field\")")->execute()->value();
}
/**
* Return the first row that would be returned by this full DataQuery
* Note that this will issue a separate SELECT ... LIMIT 1 query.
*/
function firstRow() {
return $this->getFinalisedQuery()->firstRow();
}
/**
* Return the last row that would be returned by this full DataQuery
* Note that this will issue a separate SELECT ... LIMIT query.
*/
function lastRow() {
return $this->getFinalisedQuery()->lastRow();
}
/**
* Update the SELECT clause of the query with the columns from the given table
*/
protected function selectAllFromTable(SQLQuery &$query, $tableClass) {
// Add SQL for multi-value fields
$databaseFields = DataObject::database_fields($tableClass);
$compositeFields = DataObject::composite_fields($tableClass, false);
if($databaseFields) foreach($databaseFields as $k => $v) {
if(!isset($compositeFields[$k])) {
// Update $collidingFields if necessary
if(isset($query->select[$k])) {
if(!isset($this->collidingFields[$k])) $this->collidingFields[$k] = array($query->select[$k]);
$this->collidingFields[$k][] = "\"$tableClass\".\"$k\"";
} else {
$query->select[$k] = "\"$tableClass\".\"$k\"";
}
}
}
if($compositeFields) foreach($compositeFields as $k => $v) {
if($v) {
$dbO = Object::create_from_string($v, $k);
$dbO->addToQuery($query);
}
}
}
/**
* Set the HAVING clause of this query
*/
function having($having) {
if($having) {
$clone = $this;
$clone->query->having[] = $having;
return $clone;
} else {
return $this;
}
}
/**
* Set the WHERE clause of this query
*/
function filter($filter) {
if($filter) {
$clone = $this;
$clone->query->where($filter);
return $clone;
} else {
return $this;
}
}
/**
* Set the ORDER BY clause of this query
*/
function sort($sort) {
if($sort) {
$clone = $this;
// Add quoting to sort expression if it's a simple column name
if(!is_array($sort) && preg_match('/^[A-Z][A-Z0-9_]*$/i', $sort)) $sort = "\"$sort\"";
$clone->query->orderby($sort);
return $clone;
} else {
return $this;
}
}
/**
* Set the limit of this query
*/
function limit($limit) {
if($limit) {
$clone = $this;
$clone->query->limit($limit);
return $clone;
} else {
return $this;
}
}
/**
* Add a join clause to this query
* @deprecated Use innerJoin() or leftJoin() instead.
*/
function join($join) {
if($join) {
$clone = $this;
$clone->query->from[] = $join;
// TODO: This needs to be resolved for all databases
if(DB::getConn() instanceof MySQLDatabase) $clone->query->groupby[] = reset($clone->query->from) . ".\"ID\"";
return $clone;
} else {
return $this;
}
}
/**
* Add an INNER JOIN clause to this queyr
* @param $table The table to join to.
* @param $onClause The filter for the join.
*/
public function innerJoin($table, $onClause, $alias = null) {
if($table) {
$clone = $this;
$clone->query->innerJoin($table, $onClause, $alias);
return $clone;
} else {
return $this;
}
}
/**
* Add a LEFT JOIN clause to this queyr
* @param $table The table to join to.
* @param $onClause The filter for the join.
*/
public function leftJoin($table, $onClause, $alias = null) {
if($table) {
$clone = $this;
$clone->query->leftJoin($table, $onClause, $alias);
return $clone;
} else {
return $this;
}
}
/**
* Select the given fields from the given table
*/
public function selectFromTable($table, $fields) {
$fieldExpressions = array_map(create_function('$item',
"return '\"$table\".\"' . \$item . '\"';"), $fields);
$this->select($fieldExpressions);
}
/**
* Query the given field column from the database and return as an array.
*/
public function column($field = 'ID') {
$query = $this->getFinalisedQuery();
$query->select($this->expressionForField($field, $query));
return $query->execute()->column();
}
protected function expressionForField($field, $query) {
// Special case for ID
if($field == 'ID') {
$baseClass = ClassInfo::baseDataClass($this->dataClass);
return "\"$baseClass\".\"ID\"";
} else {
return $query->expressionForField($field);
}
}
/**
* Clear the selected fields to start over
*/
public function clearSelect() {
$this->query->select = array();
return $this;
}
/**
* Select the given field expressions. You must do your own escaping
*/
protected function select($fieldExpressions) {
$this->query->select = array_merge($this->query->select, $fieldExpressions);
}
//// QUERY PARAMS
/**
* An arbitrary store of query parameters that can be used by decorators.
* @todo This will probably be made obsolete if we have subclasses of DataList and/or DataQuery.
*/
private $queryParams;
/**
* Set an arbitrary query parameter, that can be used by decorators to add additional meta-data to the query.
* It's expected that the $key will be namespaced, e.g, 'Versioned.stage' instead of just 'stage'.
*/
function setQueryParam($key, $value) {
$this->queryParams[$key] = $value;
}
/**
* Set an arbitrary query parameter, that can be used by decorators to add additional meta-data to the query.
*/
function getQueryParam($key) {
if(isset($this->queryParams[$key])) return $this->queryParams[$key];
else return null;
}
}
?>