silverstripe-framework/model/SQLQuery.php

565 lines
15 KiB
PHP
Executable File

<?php
/**
* Object representing a SQL query.
* The various parts of the SQL query can be manipulated individually.
*
* Caution: Only supports SELECT (default) and DELETE at the moment.
*
* @todo Add support for INSERT and UPDATE queries
*
* @package sapphire
* @subpackage model
*/
class SQLQuery {
/**
* An array of fields to select.
* @var array
*/
public $select = array();
/**
* An array of join clauses. The first one is just the table name.
* @var array
*/
public $from = array();
/**
* An array of filters.
* @var array
*/
public $where = array();
/**
* An ORDER BY clause.
* @var string
*/
public $orderby;
/**
* An array of fields to group by.
* @var array
*/
public $groupby = array();
/**
* An array of having clauses.
* @var array
*/
public $having = array();
/**
* A limit clause.
* @var string
*/
public $limit;
/**
* If this is true DISTINCT will be added to the SQL.
* @var boolean
*/
public $distinct = false;
/**
* If this is true, this statement will delete rather than select.
* @var boolean
*/
public $delete = false;
/**
* The logical connective used to join WHERE clauses. Defaults to AND.
* @var string
*/
public $connective = 'AND';
/**
* Keep an internal register of find/replace pairs to execute when it's time to actually get the
* query SQL.
*/
private $replacementsOld = array(), $replacementsNew = array();
/**
* Construct a new SQLQuery.
*
* @param array $select An array of fields to select.
* @param array $from An array of join clauses. The first one should be just the table name.
* @param array $where An array of filters, to be inserted into the WHERE clause.
* @param string $orderby An ORDER BY clause.
* @param array $groupby An array of fields to group by.
* @param array $having An array of having clauses.
* @param string $limit A LIMIT clause.
*
* TODO: perhaps we can quote things here instead of requiring all the parameters to be quoted
* by this stage.
*/
function __construct($select = "*", $from = array(), $where = "", $orderby = "", $groupby = "", $having = "", $limit = "") {
$this->select($select);
// @todo
$this->from = is_array($from) ? $from : array(str_replace(array('"','`'),'',$from) => $from);
$this->where($where);
$this->orderby($orderby);
$this->groupby($groupby);
$this->having($having);
$this->limit($limit);
}
/**
* Specify the list of columns to be selected by the query.
*
* <code>
* // pass fields to select as single parameter array
* $query->select(array("Col1","Col2"))->from("MyTable");
*
* // pass fields to select as multiple parameters
* $query->select("Col1", "Col2")->from("MyTable");
* </code>
*
* @param mixed $fields
* @return SQLQuery
*/
public function select($fields) {
if (func_num_args() > 1) {
$this->select = func_get_args();
} else {
$this->select = is_array($fields) ? $fields : array($fields);
}
return $this;
}
/**
* Specify the target table to select from.
*
* <code>
* $query->from("MyTable"); // SELECT * FROM MyTable
* </code>
*
* @param string $table
* @return SQLQuery This instance
*/
public function from($table) {
$this->from[str_replace(array('"','`'),'',$table)] = $table;
return $this;
}
/**
* Add a LEFT JOIN criteria to the FROM clause.
*
* @param String $table Table name (unquoted)
* @param String $onPredicate The "ON" SQL fragment in a "LEFT JOIN ... AS ... ON ..." statement.
* Needs to be valid (quoted) SQL.
* @param String $tableAlias Optional alias which makes it easier to identify and replace joins later on
* @return SQLQuery This instance
*/
public function leftJoin($table, $onPredicate, $tableAlias=null) {
if( !$tableAlias ) {
$tableAlias = $table;
}
$this->from[$tableAlias] = "LEFT JOIN \"$table\" AS \"$tableAlias\" ON $onPredicate";
return $this;
}
/**
* Add an INNER JOIN criteria to the FROM clause.
*
* @param String $table Table name (unquoted)
* @param String $onPredicate The "ON" SQL fragment in a "LEFT JOIN ... AS ... ON ..." statement.
* Needs to be valid (quoted) SQL.
* @param String $tableAlias Optional alias which makes it easier to identify and replace joins later on
* @return SQLQuery This instance
*/
public function innerJoin($table, $onPredicate, $tableAlias=null) {
if( !$tableAlias ) {
$tableAlias = $table;
}
$this->from[$tableAlias] = "INNER JOIN \"$table\" AS \"$tableAlias\" ON $onPredicate";
return $this;
}
/**
* Returns true if we are already joining to the given table alias
*/
public function isJoinedTo($tableAlias) {
return isset($this->from[$tableAlias]);
}
/**
* Pass LIMIT clause either as SQL snippet or in array format.
* Internally, limit will always be stored as a map containing the keys 'start' and 'limit'
*
* @param string|array $limit
* @return SQLQuery This instance
*/
public function limit($limit) {
if($limit && is_numeric($limit)) {
$this->limit = array(
'start' => 0,
'limit' => $limit,
);
} else if($limit && is_string($limit)) {
if(strpos($limit,',') !== false) list($start, $innerLimit) = explode(',', $limit, 2);
else list($innerLimit, $start) = explode(' OFFSET ', strtoupper($limit), 2);
$this->limit = array(
'start' => trim($start),
'limit' => trim($innerLimit),
);
} else {
$this->limit = $limit;
}
return $this;
}
/**
* Pass ORDER BY clause either as SQL snippet or in array format.
*
* @todo Implement passing of multiple orderby pairs in nested array syntax,
* e.g. array(array('sort'=>'A','dir'=>'asc'),array('sort'=>'B'))
*
* @param string|array $orderby
* @return SQLQuery This instance
*/
public function orderby($orderby) {
// if passed as an array, assume two array values with column and direction (asc|desc)
if(is_array($orderby)) {
if(!array_key_exists('sort', $orderby)) user_error('SQLQuery::orderby(): Wrong format for $orderby array', E_USER_ERROR);
if(isset($orderby['sort']) && !empty($orderby['sort']) && isset($orderby['dir']) && !empty($orderby['dir'])) {
$combinedOrderby = "\"" . Convert::raw2sql($orderby['sort']) . "\" " . Convert::raw2sql(strtoupper($orderby['dir']));
} elseif(isset($orderby['sort']) && !empty($orderby['sort'])) {
$combinedOrderby = "\"" . Convert::raw2sql($orderby['sort']) . "\"";
} else {
$combinedOrderby = false;
}
} else {
$combinedOrderby = $orderby;
}
// If sort contains a function call, let's move the sort clause into a separate selected field.
// Some versions of MySQL choke if you have a group function referenced directly in the ORDER BY
if($combinedOrderby && strpos($combinedOrderby,'(') !== false && strtoupper(trim($combinedOrderby)) != DB::getConn()->random()) {
// Sort can be "Col1 DESC|ASC, Col2 DESC|ASC", we need to handle that
$sortParts = explode(",", $combinedOrderby);
// If you have select if(X,A,B),C then the array will return 'if(X','A','B)','C'.
// Turn this into 'if(X,A,B)','C' by counting brackets
while(list($i,$sortPart) = each($sortParts)) {
while(substr_count($sortPart,'(') > substr_count($sortPart,')')) {
list($i,$nextSortPart) = each($sortParts);
if($i === null) break;
$sortPart .= ',' . $nextSortPart;
}
$lumpedSortParts[] = $sortPart;
}
foreach($lumpedSortParts as $i => $sortPart) {
$sortPart = trim($sortPart);
if(substr(strtolower($sortPart),-5) == ' desc') {
$this->select[] = substr($sortPart,0,-5) . " AS \"_SortColumn{$i}\"";
$newSorts[] = "\"_SortColumn{$i}\" DESC";
} else if(substr(strtolower($sortPart),-4) == ' asc') {
$this->select[] = substr($sortPart,0,-4) . " AS \"_SortColumn{$i}\"";
$newSorts[] = "\"_SortColumn{$i}\" ASC";
} else {
$this->select[] = "$sortPart AS \"_SortColumn{$i}\"";
$newSorts[] = "\"_SortColumn{$i}\" ASC";
}
}
$combinedOrderby = implode(", ", $newSorts);
}
if(!empty($combinedOrderby)) $this->orderby = $combinedOrderby;
return $this;
}
/**
* Add a GROUP BY clause.
*
* @param string|array $groupby
* @return SQLQuery
*/
public function groupby($groupby) {
if(is_array($groupby)) {
$this->groupby = array_merge($this->groupby, $groupby);
} elseif(!empty($groupby)) {
$this->groupby[] = $groupby;
}
return $this;
}
/**
* Add a HAVING clause.
*
* @param string|array $having
* @return SQLQuery
*/
public function having($having) {
if(is_array($having)) {
$this->having = array_merge($this->having, $having);
} elseif(!empty($having)) {
$this->having[] = $having;
}
return $this;
}
/**
* Apply a predicate filter to the where clause.
*
* Accepts a variable length of arguments, which represent
* different ways of formatting a predicate in a where clause:
*
* <code>
* // the entire predicate as a single string
* $query->where("Column = 'Value'");
*
* // an exact match predicate with a key value pair
* $query->where("Column", "Value");
*
* // a predicate with user defined operator
* $query->where("Column", "!=", "Value");
* </code>
*
*/
public function where() {
$args = func_get_args();
if (func_num_args() == 3) {
$filter = "{$args[0]} {$args[1]} '{$args[2]}'";
} elseif (func_num_args() == 2) {
$filter = "{$args[0]} = '{$args[1]}'";
} else {
$filter = $args[0];
}
if(is_array($filter)) {
$this->where = array_merge($this->where,$filter);
} elseif(!empty($filter)) {
$this->where[] = $filter;
}
return $this;
}
/**
* Use the disjunctive operator 'OR' to join filter expressions in the WHERE clause.
*/
public function useDisjunction() {
$this->connective = 'OR';
}
/**
* Use the conjunctive operator 'AND' to join filter expressions in the WHERE clause.
*/
public function useConjunction() {
$this->connective = 'AND';
}
/**
* Swap the use of one table with another.
* @param string $old Name of the old table.
* @param string $new Name of the new table.
*/
function renameTable($old, $new) {
$this->replaceText("`$old`", "`$new`");
$this->replaceText("\"$old\"", "\"$new\"");
}
/**
* Swap some text in the SQL query with another.
* @param string $old The old text.
* @param string $new The new text.
*/
function replaceText($old, $new) {
$this->replacementsOld[] = $old;
$this->replacementsNew[] = $new;
}
/**
* Return an SQL WHERE clause to filter a SELECT query.
*
* @return string
*/
function getFilter() {
return ($this->where) ? implode(") {$this->connective} (" , $this->where) : '';
}
/**
* Generate the SQL statement for this query.
*
* @return string
*/
function sql() {
$sql = DB::getConn()->sqlQueryToString($this);
if($this->replacementsOld) $sql = str_replace($this->replacementsOld, $this->replacementsNew, $sql);
return $sql;
}
/**
* Return the generated SQL string for this query
*
* @return string
*/
function __toString() {
return $this->sql();
}
/**
* Execute this query.
* @return SS_Query
*/
function execute() {
return DB::query($this->sql(), E_USER_ERROR);
}
/**
* Checks whether this query is for a specific ID in a table
*
* @todo Doesn't work with combined statements (e.g. "Foo='bar' AND ID=5")
*
* @return boolean
*/
function filtersOnID() {
$regexp = '/^(.*\.)?("|`)?ID("|`)?\s?=/';
// Sometimes the ID filter will be the 2nd element, if there's a ClasssName filter first.
if(isset($this->where[0]) && preg_match($regexp, $this->where[0])) return true;
if(isset($this->where[1]) && preg_match($regexp, $this->where[1])) return true;
return false;
}
/**
* Checks whether this query is filtering on a foreign key, ie finding a has_many relationship
*
* @todo Doesn't work with combined statements (e.g. "Foo='bar' AND ParentID=5")
*
* @return boolean
*/
function filtersOnFK() {
return (
$this->where
&& preg_match('/^(.*\.)?("|`)?[a-zA-Z]+ID("|`)?\s?=/', $this->where[0])
);
}
/// VARIOUS TRANSFORMATIONS BELOW
/**
* Return the number of rows in this query if the limit were removed. Useful in paged data sets.
* @return int
*/
function unlimitedRowCount( $column = null) {
// we can't clear the select if we're relying on its output by a HAVING clause
if(count($this->having)) {
$records = $this->execute();
return $records->numRecords();
}
$clone = clone $this;
$clone->limit = null;
$clone->orderby = null;
// Choose a default column
if($column == null) {
if($this->groupby) {
$countQuery = new SQLQuery();
$countQuery->select = array("count(*)");
$countQuery->from = array('(' . $clone->sql() . ') all_distinct');
return $countQuery->execute()->value();
} else {
$clone->select = array("count(*)");
}
} else {
$clone->select = array("count($column)");
}
$clone->groupby = null;
return $clone->execute()->value();
}
/**
* Returns true if this query can be sorted by the given field.
* Note that the implementation of this method is a little crude at the moment, it wil return
* "false" more often that is strictly necessary.
*/
function canSortBy($fieldName) {
$fieldName = preg_replace('/(\s+?)(A|DE)SC$/', '', $fieldName);
$sql = $this->sql();
$selects = $this->select;
foreach($selects as $i => $sel) {
if (preg_match('/"(.*)"\."(.*)"/', $sel, $matches)) $selects[$i] = $matches[2];
}
$SQL_fieldName = Convert::raw2sql($fieldName);
return (in_array($SQL_fieldName,$selects) || stripos($sql,"AS {$SQL_fieldName}"));
}
/**
* Return the number of rows in this query if the limit were removed. Useful in paged data sets.
* @return int
*
* TODO Respect HAVING and GROUPBY, which can affect the result-count
*/
function count( $column = null) {
// Choose a default column
if($column == null) {
if($this->groupby) {
$column = 'DISTINCT ' . implode(", ", $this->groupby);
} else {
$column = '*';
}
}
$clone = clone $this;
$clone->select = array("count($column)");
$clone->limit = null;
$clone->orderby = null;
$clone->groupby = null;
$count = $clone->execute()->value();
// If there's a limit set, then that limit is going to heavily affect the count
if($this->limit) {
if($count >= ($this->limit['start'] + $this->limit['limit']))
return $this->limit['limit'];
else
return max(0, $count - $this->limit['start']);
// Otherwise, the count is going to be the output of the SQL query
} else {
return $count;
}
}
/**
* Returns a query that returns only the first row of this query
*/
function firstRow() {
$query = clone $this;
$offset = $this->limit ? $this->limit['start'] : 0;
$query->limit(array('start' => $offset, 'limit' => 1));
return $query;
}
/**
* Returns a query that returns only the last row of this query
*/
function lastRow() {
$query = clone $this;
$offset = $this->limit ? $this->limit['start'] : 0;
$query->limit(array('start' => $this->count() + $offset - 1, 'limit' => 1));
return $query;
}
}
?>