/**
* Compiles the GROUP BY clause of a SQL query.
*
* @return array
*/
private function compileGroup()
{
if (!$this->group) {
return null;
}
$parts = [];
foreach ($this->group as $column) {
$parts[] = e\columnize($column, $this->alias);
}
return 'GROUP BY ' . implode($parts, ', ');
}
/**
* Compiles the ORDER BY clause of a SQL query.
*
* @return array
*/
private function compileOrder()
{
if (!$this->order) {
return null;
}
$parts = [];
foreach ($this->order as $source => $dir) {
$parts[] = e\columnize($source, $this->alias) . ' ' . strtoupper($dir);
}
return 'ORDER BY ' . implode($parts, ', ');
}
/**
* @return array
*/
private function compilePart($alias, $type, $expr, array $params)
{
$ret = [];
// Passing a simple string like 'foo.bar = ?', [$bar] should
// work fine, so we can skip the complicated array syntax.
if (is_string($expr)) {
return [['expr' => $expr, 'params' => $params, 'type' => $type]];
}
// Allow passing completely bare expressions.
if ($expr instanceof ExpressionInterface) {
return [['expr' => $expr->getExpr($alias), 'params' => $expr->getBinds(), 'type' => $type]];
}
foreach ($expr as $column => $value) {
// Allow passing a literal string, which is useful for
// completely literal expressions (such as those used for joins).
if (is_int($column)) {
$ret[] = ['expr' => $value, 'type' => $type, 'params' => []];
continue;
}
// Try and provide a table alias if possible.
$column = e\columnize($column, $alias);
// And automatically detect an IN if possible.
if (is_array($value)) {
$value = e\in($value);
}
if (!$value instanceof ExpressionInterface) {
$value = e\eq($value);
}
$ret[] = ['expr' => $value->getExpr($column), 'params' => $value->getBinds(), 'type' => $type];
}
return $ret;
}
/**
* Compiles the columns to select in a SELECT.
*
* @return string
*/
private function compileColumns()
{
if (!$this->select) {
$this->select = ['*'];
}
$parts = [];
foreach ($this->select as $column => $alias) {
// Allow no aliasing as well, as denoted by an it key
if (is_int($column)) {
$parts[] = e\columnize($alias, $this->alias);
} else {
$column = e\columnize($column, $this->alias);
$parts[] = e\alias($column, $alias);
}
}
return implode($parts, ', ');
}
