Файл: framework/model/connect/Query.php
Строк: 237
<?php
/**
* Abstract query-result class.
* Once again, this should be subclassed by an actual database implementation. It will only
* ever be constructed by a subclass of SS_Database. The result of a database query - an iteratable object
* that's returned by DB::SS_Query
*
* Primarily, the SS_Query class takes care of the iterator plumbing, letting the subclasses focusing
* on providing the specific data-access methods that are required: {@link nextRecord()}, {@link numRecords()}
* and {@link seek()}
* @package framework
* @subpackage model
*/
abstract class SS_Query implements Iterator {
/**
* The current record in the interator.
*
* @var array
*/
protected $currentRecord = null;
/**
* The number of the current row in the interator.
*
* @var int
*/
protected $rowNum = -1;
/**
* Flag to keep track of whether iteration has begun, to prevent unnecessary seeks
*
* @var bool
*/
protected $queryHasBegun = false;
/**
* Return an array containing all the values from a specific column. If no column is set, then the first will be
* returned
*
* @param string $column
* @return array
*/
public function column($column = null) {
$result = array();
while ($record = $this->next()) {
if ($column) {
$result[] = $record[$column];
} else {
$result[] = $record[key($record)];
}
}
return $result;
}
/**
* Return an array containing all values in the leftmost column, where the keys are the
* same as the values.
*
* @return array
*/
public function keyedColumn() {
$column = array();
foreach ($this as $record) {
$val = $record[key($record)];
$column[$val] = $val;
}
return $column;
}
/**
* Return a map from the first column to the second column.
*
* @return array
*/
public function map() {
$column = array();
foreach ($this as $record) {
$key = reset($record);
$val = next($record);
$column[$key] = $val;
}
return $column;
}
/**
* Returns the next record in the iterator.
*
* @return array
*/
public function record() {
return $this->next();
}
/**
* Returns the first column of the first record.
*
* @return string
*/
public function value() {
$record = $this->next();
if ($record) return $record[key($record)];
}
/**
* Return an HTML table containing the full result-set
*
* @return string
*/
public function table() {
$first = true;
$result = "<table>n";
foreach ($this as $record) {
if ($first) {
$result .= "<tr>";
foreach ($record as $k => $v) {
$result .= "<th>" . Convert::raw2xml($k) . "</th> ";
}
$result .= "</tr> n";
}
$result .= "<tr>";
foreach ($record as $k => $v) {
$result .= "<td>" . Convert::raw2xml($v) . "</td> ";
}
$result .= "</tr> n";
$first = false;
}
$result .= "</table>n";
if ($first) return "No records found";
return $result;
}
/**
* Iterator function implementation. Rewind the iterator to the first item and return it.
* Makes use of {@link seek()} and {@link numRecords()}, takes care of the plumbing.
*
* @return array
*/
public function rewind() {
if ($this->queryHasBegun && $this->numRecords() > 0) {
$this->queryHasBegun = false;
$this->currentRecord = null;
return $this->seek(0);
}
}
/**
* Iterator function implementation. Return the current item of the iterator.
*
* @return array
*/
public function current() {
if (!$this->currentRecord) {
return $this->next();
} else {
return $this->currentRecord;
}
}
/**
* Iterator function implementation. Return the first item of this iterator.
*
* @return array
*/
public function first() {
$this->rewind();
return $this->current();
}
/**
* Iterator function implementation. Return the row number of the current item.
*
* @return int
*/
public function key() {
return $this->rowNum;
}
/**
* Iterator function implementation. Return the next record in the iterator.
* Makes use of {@link nextRecord()}, takes care of the plumbing.
*
* @return array
*/
public function next() {
$this->queryHasBegun = true;
$this->currentRecord = $this->nextRecord();
$this->rowNum++;
return $this->currentRecord;
}
/**
* Iterator function implementation. Check if the iterator is pointing to a valid item.
*
* @return bool
*/
public function valid() {
if (!$this->queryHasBegun) $this->next();
return $this->currentRecord !== false;
}
/**
* Return the next record in the query result.
*
* @return array
*/
abstract public function nextRecord();
/**
* Return the total number of items in the query result.
*
* @return int
*/
abstract public function numRecords();
/**
* Go to a specific row number in the query result and return the record.
*
* @param int $rowNum Row number to go to.
* @return array
*/
abstract public function seek($rowNum);
}