/**
* Compile the SQL partial for a JOIN statement and return it.
*
* @param object Database instance
* @return string
*/
public function compile(\Database_Connection $db)
{
if ($this->_type) {
$sql = strtoupper($this->_type) . ' JOIN';
} else {
$sql = 'JOIN';
}
// Quote the table name that is being joined
$sql .= ' ' . $db->quote_table($this->_table) . ' ON ';
$conditions = array();
foreach ($this->_on as $condition) {
// Split the condition
list($c1, $op, $c2) = $condition;
if ($op) {
// Make the operator uppercase and spaced
$op = ' ' . strtoupper($op);
}
// Quote each of the identifiers used for the condition
$conditions[] = $db->quote_identifier($c1) . $op . ' ' . $db->quote_identifier($c2);
}
// Concat the conditions "... AND ..."
$sql .= '(' . implode(' AND ', $conditions) . ')';
return $sql;
}
/**
* Compiles an array of ORDER BY statements into an SQL partial.
*
* @param object Database instance
* @param array sorting columns
* @return string
*/
protected function _compile_order_by(\Database_Connection $db, array $columns)
{
$sort = array();
foreach ($columns as $group) {
list($column, $direction) = $group;
if (!empty($direction)) {
// Make the direction uppercase
$direction = ' ' . strtoupper($direction);
}
$sort[] = $db->quote_identifier($column) . $direction;
}
return 'ORDER BY ' . implode(', ', $sort);
}
