/**
* Compiles an array of ORDER BY statements into an SQL partial.
*
* @param array $columns sorting columns
* @return string
*/
protected function compileOrderBy(array $columns)
{
$sort = array();
foreach ($columns as $group) {
list($column, $direction) = $group;
if (is_array($column)) {
$column = $this->quoter->quoteIdentifier(end($column));
} else {
$column = $this->quoter->quoteColumn($column);
}
if ($direction) {
$direction = ' ' . strtoupper($direction);
}
$sort[] = $column . $direction;
}
return 'ORDER BY ' . implode(', ', $sort);
}
/**
* Compile the SQL partial for a JOIN statement and return it.
*
* @return string
*/
public function compile()
{
if (null !== $this->type) {
$sql = strtoupper($this->type) . ' JOIN';
} else {
$sql = 'JOIN';
}
$sql .= ' ' . $this->quoter->quoteTable($this->table);
if (!empty($this->using)) {
$sql .= ' USING (' . implode(', ', array_map(array($this->quoter, 'quoteColumn'), $this->using)) . ')';
} else {
$conditions = array();
foreach ($this->on as $condition) {
list($c1, $op, $c2) = $condition;
if ($op) {
$op = ' ' . strtoupper($op);
}
$conditions[] = $this->quoter->quoteColumn($c1) . $op . ' ' . $this->quoter->quoteColumn($c2);
}
$sql .= ' ON (' . implode(' AND ', $conditions) . ')';
}
return $sql;
}
/**
* Creates a new SQL query of the specified type.
*
* @param string $sql query string
*/
public function __construct($sql)
{
$this->sql = $sql;
$this->quoter = Quoter::instance();
}