Viewing file:  JoinKeyword.php (6.3 KB) -rw-r--r--
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<?php
/**
* `JOIN` keyword parser.
*/
declare(strict_types=1);
namespace PhpMyAdmin\SqlParser\Components;
use PhpMyAdmin\SqlParser\Component;
use PhpMyAdmin\SqlParser\Parser;
use PhpMyAdmin\SqlParser\Token;
use PhpMyAdmin\SqlParser\TokensList;
use function array_search;
use function implode;
/**
* `JOIN` keyword parser.
*/
class JoinKeyword extends Component
{
/**
* Types of join.
*
* @var array
*/
public static $JOINS = [
'CROSS JOIN' => 'CROSS',
'FULL JOIN' => 'FULL',
'FULL OUTER JOIN' => 'FULL',
'INNER JOIN' => 'INNER',
'JOIN' => 'JOIN',
'LEFT JOIN' => 'LEFT',
'LEFT OUTER JOIN' => 'LEFT',
'RIGHT JOIN' => 'RIGHT',
'RIGHT OUTER JOIN' => 'RIGHT',
'NATURAL JOIN' => 'NATURAL',
'NATURAL LEFT JOIN' => 'NATURAL LEFT',
'NATURAL RIGHT JOIN' => 'NATURAL RIGHT',
'NATURAL LEFT OUTER JOIN' => 'NATURAL LEFT OUTER',
'NATURAL RIGHT OUTER JOIN' => 'NATURAL RIGHT OUTER',
'STRAIGHT_JOIN' => 'STRAIGHT',
];
/**
* Type of this join.
*
* @see static::$JOINS
*
* @var string
*/
public $type;
/**
* Join expression.
*
* @var Expression
*/
public $expr;
/**
* Join conditions.
*
* @var Condition[]
*/
public $on;
/**
* Columns in Using clause.
*
* @var ArrayObj
*/
public $using;
/**
* @see JoinKeyword::$JOINS
*
* @param string $type Join type
* @param Expression $expr join expression
* @param Condition[] $on join conditions
* @param ArrayObj $using columns joined
*/
public function __construct($type = null, $expr = null, $on = null, $using = null)
{
$this->type = $type;
$this->expr = $expr;
$this->on = $on;
$this->using = $using;
}
/**
* @param Parser $parser the parser that serves as context
* @param TokensList $list the list of tokens that are being parsed
* @param array $options parameters for parsing
*
* @return JoinKeyword[]
*/
public static function parse(Parser $parser, TokensList $list, array $options = [])
{
$ret = [];
$expr = new static();
/**
* The state of the parser.
*
* Below are the states of the parser.
*
* 0 -----------------------[ JOIN ]----------------------> 1
*
* 1 -----------------------[ expr ]----------------------> 2
*
* 2 ------------------------[ ON ]-----------------------> 3
* 2 -----------------------[ USING ]---------------------> 4
*
* 3 --------------------[ conditions ]-------------------> 0
*
* 4 ----------------------[ columns ]--------------------> 0
*
* @var int
*/
$state = 0;
// By design, the parser will parse first token after the keyword.
// In this case, the keyword must be analyzed too, in order to determine
// the type of this join.
if ($list->idx > 0) {
--$list->idx;
}
for (; $list->idx < $list->count; ++$list->idx) {
/**
* Token parsed at this moment.
*
* @var Token
*/
$token = $list->tokens[$list->idx];
// End of statement.
if ($token->type === Token::TYPE_DELIMITER) {
break;
}
// Skipping whitespaces and comments.
if (($token->type === Token::TYPE_WHITESPACE) || ($token->type === Token::TYPE_COMMENT)) {
continue;
}
if ($state === 0) {
if (($token->type === Token::TYPE_KEYWORD)
&& ! empty(static::$JOINS[$token->keyword])
) {
$expr->type = static::$JOINS[$token->keyword];
$state = 1;
} else {
break;
}
} elseif ($state === 1) {
$expr->expr = Expression::parse($parser, $list, ['field' => 'table']);
$state = 2;
} elseif ($state === 2) {
if ($token->type === Token::TYPE_KEYWORD) {
switch ($token->keyword) {
case 'ON':
$state = 3;
break;
case 'USING':
$state = 4;
break;
default:
if (! empty(static::$JOINS[$token->keyword])
) {
$ret[] = $expr;
$expr = new static();
$expr->type = static::$JOINS[$token->keyword];
$state = 1;
} else {
/* Next clause is starting */
break 2;
}
break;
}
}
} elseif ($state === 3) {
$expr->on = Condition::parse($parser, $list);
$ret[] = $expr;
$expr = new static();
$state = 0;
} elseif ($state === 4) {
$expr->using = ArrayObj::parse($parser, $list);
$ret[] = $expr;
$expr = new static();
$state = 0;
}
}
if (! empty($expr->type)) {
$ret[] = $expr;
}
--$list->idx;
return $ret;
}
/**
* @param JoinKeyword[] $component the component to be built
* @param array $options parameters for building
*
* @return string
*/
public static function build($component, array $options = [])
{
$ret = [];
foreach ($component as $c) {
$ret[] = array_search($c->type, static::$JOINS) . ' ' . $c->expr
. (! empty($c->on)
? ' ON ' . Condition::build($c->on) : '')
. (! empty($c->using)
? ' USING ' . ArrayObj::build($c->using) : '');
}
return implode(' ', $ret);
}
}
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