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<?php
/**
* Defines the parser of the library.
*
* This is one of the most important components, along with the lexer.
*
* @package SqlParser
*/
namespace {
if (!function_exists('__')) {
/**
* Translates the given string.
*
* @param string $str String to be translated.
*
* @return string
*/
function __($str)
{
return $str;
}
}
}
namespace SqlParser {
use SqlParserExceptionsParserException;
use SqlParserStatementsSelectStatement;
use SqlParserStatementsTransactionStatement;
/**
* Takes multiple tokens (contained in a Lexer instance) as input and builds a
* parse tree.
*
* @category Parser
* @package SqlParser
* @author Dan Ungureanu <udan1107@gmail.com>
* @license http://opensource.org/licenses/GPL-2.0 GNU Public License
*/
class Parser
{
/**
* Array of classes that are used in parsing the SQL statements.
*
* @var array
*/
public static $STATEMENT_PARSERS = array(
// MySQL Utility Statements
'EXPLAIN' => 'SqlParser\\Statements\\ExplainStatement',
'DESCRIBE' => 'SqlParser\\Statements\\ExplainStatement',
'HELP' => '',
'USE' => '',
'STATUS' => '',
// Table Maintenance Statements
// https://dev.mysql.com/doc/refman/5.7/en/table-maintenance-sql.html
'ANALYZE' => 'SqlParser\\Statements\\AnalyzeStatement',
'BACKUP' => 'SqlParser\\Statements\\BackupStatement',
'CHECK' => 'SqlParser\\Statements\\CheckStatement',
'CHECKSUM' => 'SqlParser\\Statements\\ChecksumStatement',
'OPTIMIZE' => 'SqlParser\\Statements\\OptimizeStatement',
'REPAIR' => 'SqlParser\\Statements\\RepairStatement',
'RESTORE' => 'SqlParser\\Statements\\RestoreStatement',
// Database Administration Statements
// https://dev.mysql.com/doc/refman/5.7/en/sql-syntax-server-administration.html
'SET' => 'SqlParser\\Statements\\SetStatement',
'SHOW' => 'SqlParser\\Statements\\ShowStatement',
// Data Definition Statements.
// https://dev.mysql.com/doc/refman/5.7/en/sql-syntax-data-definition.html
'ALTER' => 'SqlParser\\Statements\\AlterStatement',
'CREATE' => 'SqlParser\\Statements\\CreateStatement',
'DROP' => 'SqlParser\\Statements\\DropStatement',
'RENAME' => 'SqlParser\\Statements\\RenameStatement',
'TRUNCATE' => 'SqlParser\\Statements\\TruncateStatement',
// Data Manipulation Statements.
// https://dev.mysql.com/doc/refman/5.7/en/sql-syntax-data-manipulation.html
'CALL' => 'SqlParser\\Statements\\CallStatement',
'DELETE' => 'SqlParser\\Statements\\DeleteStatement',
'DO' => '',
'HANDLER' => '',
'INSERT' => 'SqlParser\\Statements\\InsertStatement',
'LOAD' => '',
'REPLACE' => 'SqlParser\\Statements\\ReplaceStatement',
'SELECT' => 'SqlParser\\Statements\\SelectStatement',
'UPDATE' => 'SqlParser\\Statements\\UpdateStatement',
// Prepared Statements.
// https://dev.mysql.com/doc/refman/5.7/en/sql-syntax-prepared-statements.html
'PREPARE' => '',
'EXECUTE' => '',
// Transactional and Locking Statements
// https://dev.mysql.com/doc/refman/5.7/en/commit.html
'START TRANSACTION' => 'SqlParser\\Statements\\TransactionStatement',
'BEGIN' => 'SqlParser\\Statements\\TransactionStatement',
'COMMIT' => 'SqlParser\\Statements\\TransactionStatement',
'ROLLBACK' => 'SqlParser\\Statements\\TransactionStatement',
);
/**
* Array of classes that are used in parsing SQL components.
*
* @var array
*/
public static $KEYWORD_PARSERS = array(
// This is not a proper keyword and was added here to help the
// formatter.
'PARTITION BY' => array(),
'SUBPARTITION BY' => array(),
// This is not a proper keyword and was added here to help the
// builder.
'_OPTIONS' => array(
'class' => 'SqlParser\\Components\\OptionsArray',
'field' => 'options',
),
'UNION' => array(
'class' => 'SqlParser\\Components\\UnionKeyword',
'field' => 'union',
),
// Actual clause parsers.
'ALTER' => array(
'class' => 'SqlParser\\Components\\Expression',
'field' => 'table',
'options' => array('skipColumn' => true),
),
'ANALYZE' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'tables',
'options' => array('skipColumn' => true),
),
'BACKUP' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'tables',
'options' => array('skipColumn' => true),
),
'CALL' => array(
'class' => 'SqlParser\\Components\\FunctionCall',
'field' => 'call',
),
'CHECK' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'tables',
'options' => array('skipColumn' => true),
),
'CHECKSUM' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'tables',
'options' => array('skipColumn' => true),
),
'DROP' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'fields',
'options' => array('skipColumn' => true),
),
'FROM' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'from',
'options' => array('skipColumn' => true),
),
'GROUP BY' => array(
'class' => 'SqlParser\\Components\\OrderKeyword',
'field' => 'group',
),
'HAVING' => array(
'class' => 'SqlParser\\Components\\Condition',
'field' => 'having',
),
'INTO' => array(
'class' => 'SqlParser\\Components\\IntoKeyword',
'field' => 'into',
),
'JOIN' => array(
'class' => 'SqlParser\\Components\\JoinKeyword',
'field' => 'join',
),
'LEFT JOIN' => array(
'class' => 'SqlParser\\Components\\JoinKeyword',
'field' => 'join',
),
'RIGHT JOIN' => array(
'class' => 'SqlParser\\Components\\JoinKeyword',
'field' => 'join',
),
'INNER JOIN' => array(
'class' => 'SqlParser\\Components\\JoinKeyword',
'field' => 'join',
),
'FULL JOIN' => array(
'class' => 'SqlParser\\Components\\JoinKeyword',
'field' => 'join',
),
'LIMIT' => array(
'class' => 'SqlParser\\Components\\Limit',
'field' => 'limit',
),
'OPTIMIZE' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'tables',
'options' => array('skipColumn' => true),
),
'ORDER BY' => array(
'class' => 'SqlParser\\Components\\OrderKeyword',
'field' => 'order',
),
'PARTITION' => array(
'class' => 'SqlParser\\Components\\ArrayObj',
'field' => 'partition',
),
'PROCEDURE' => array(
'class' => 'SqlParser\\Components\\FunctionCall',
'field' => 'procedure',
),
'RENAME' => array(
'class' => 'SqlParser\\Components\\RenameOperation',
'field' => 'renames',
),
'REPAIR' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'tables',
'options' => array('skipColumn' => true),
),
'RESTORE' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'tables',
'options' => array('skipColumn' => true),
),
'SET' => array(
'class' => 'SqlParser\\Components\\SetOperation',
'field' => 'set',
),
'SELECT' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'expr',
),
'TRUNCATE' => array(
'class' => 'SqlParser\\Components\\Expression',
'field' => 'table',
'options' => array('skipColumn' => true),
),
'UPDATE' => array(
'class' => 'SqlParser\\Components\\ExpressionArray',
'field' => 'tables',
'options' => array('skipColumn' => true),
),
'VALUE' => array(
'class' => 'SqlParser\\Components\\Array2d',
'field' => 'values',
),
'VALUES' => array(
'class' => 'SqlParser\\Components\\Array2d',
'field' => 'values',
),
'WHERE' => array(
'class' => 'SqlParser\\Components\\Condition',
'field' => 'where',
),
);
/**
* The list of tokens that are parsed.
*
* @var TokensList
*/
public $list;
/**
* Whether errors should throw exceptions or just be stored.
*
* @var bool
*
* @see static::$errors
*/
public $strict = false;
/**
* List of errors that occurred during parsing.
*
* Usually, the parsing does not stop once an error occurred because that
* error might be a false positive or a partial result (even a bad one)
* might be needed.
*
* @var ParserException[]
*
* @see Parser::error()
*/
public $errors = array();
/**
* List of statements parsed.
*
* @var Statement[]
*/
public $statements = array();
/**
* Constructor.
*
* @param string|UtfString|TokensList $list The list of tokens to be parsed.
* @param bool $strict Whether strict mode should be enabled or not.
*/
public function __construct($list = null, $strict = false)
{
if ((is_string($list)) || ($list instanceof UtfString)) {
$lexer = new Lexer($list, $strict);
$this->list = $lexer->list;
} elseif ($list instanceof TokensList) {
$this->list = $list;
}
$this->strict = $strict;
if ($list !== null) {
$this->parse();
}
}
/**
* Builds the parse trees.
*
* @return void
*/
public function parse()
{
/**
* Last transaction.
*
* @var TransactionStatement $lastTransaction
*/
$lastTransaction = null;
/**
* Last parsed statement.
*
* @var Statement $lastStatement
*/
$lastStatement = null;
/**
* Whether a union is parsed or not.
*
* @var bool $inUnion
*/
$inUnion = false;
/**
* The index of the last token from the last statement.
*
* @var int $prevLastIdx
*/
$prevLastIdx = -1;
/**
* The list of tokens.
*
* @var TokensList $list
*/
$list = &$this->list;
for (; $list->idx < $list->count; ++$list->idx) {
/**
* Token parsed at this moment.
*
* @var Token $token
*/
$token = $list->tokens[$list->idx];
// `DELIMITER` is not an actual statement and it requires
// special handling.
if (($token->type === Token::TYPE_NONE)
&& (strtoupper($token->token) === 'DELIMITER')
) {
// Skipping to the end of this statement.
$list->getNextOfType(Token::TYPE_DELIMITER);
$prevLastIdx = $list->idx;
continue;
}
// Statements can start with keywords only.
// Comments, whitespaces, etc. are ignored.
if ($token->type !== Token::TYPE_KEYWORD) {
if (($token->type !== TOKEN::TYPE_COMMENT)
&& ($token->type !== Token::TYPE_WHITESPACE)
&& ($token->type !== Token::TYPE_OPERATOR) // `(` and `)`
&& ($token->type !== Token::TYPE_DELIMITER)
) {
$this->error(
__('Unexpected beginning of statement.'),
$token
);
}
continue;
}
if ($token->value === 'UNION') {
$inUnion = true;
continue;
}
// Checking if it is a known statement that can be parsed.
if (empty(static::$STATEMENT_PARSERS[$token->value])) {
if (!isset(static::$STATEMENT_PARSERS[$token->value])) {
// A statement is considered recognized if the parser
// is aware that it is a statement, but it does not have
// a parser for it yet.
$this->error(
__('Unrecognized statement type.'),
$token
);
}
// Skipping to the end of this statement.
$list->getNextOfType(Token::TYPE_DELIMITER);
$prevLastIdx = $list->idx;
continue;
}
/**
* The name of the class that is used for parsing.
*
* @var string $class
*/
$class = static::$STATEMENT_PARSERS[$token->value];
/**
* Processed statement.
*
* @var Statement $statement
*/
$statement = new $class($this, $this->list);
// The first token that is a part of this token is the next token
// unprocessed by the previous statement.
// There might be brackets around statements and this shouldn't
// affect the parser
$statement->first = $prevLastIdx + 1;
// Storing the index of the last token parsed and updating the old
// index.
$statement->last = $list->idx;
$prevLastIdx = $list->idx;
// Handles unions.
if (($inUnion)
&& ($lastStatement instanceof SelectStatement)
&& ($statement instanceof SelectStatement)
) {
/**
* This SELECT statement.
*
* @var SelectStatement $statement
*/
/**
* Last SELECT statement.
*
* @var SelectStatement $lastStatement
*/
$lastStatement->union[] = $statement;
// if there are no no delimiting brackets, the `ORDER` and
// `LIMIT` keywords actually belong to the first statement.
$lastStatement->order = $statement->order;
$lastStatement->limit = $statement->limit;
$statement->order = array();
$statement->limit = null;
// The statement actually ends where the last statement in
// union ends.
$lastStatement->last = $statement->last;
$inUnion = false;
continue;
}
// Handles transactions.
if ($statement instanceof TransactionStatement) {
/**
* @var TransactionStatement $statement
*/
if ($statement->type === TransactionStatement::TYPE_BEGIN) {
$lastTransaction = $statement;
$this->statements[] = $statement;
} elseif ($statement->type === TransactionStatement::TYPE_END) {
if ($lastTransaction === null) {
// Even though an error occurred, the query is being
// saved.
$this->statements[] = $statement;
$this->error(
__('No transaction was previously started.'),
$token
);
} else {
$lastTransaction->end = $statement;
}
$lastTransaction = null;
}
continue;
}
// Finally, storing the statement.
if ($lastTransaction !== null) {
$lastTransaction->statements[] = $statement;
} else {
$this->statements[] = $statement;
}
$lastStatement = $statement;
}
}
/**
* Creates a new error log.
*
* @param string $msg The error message.
* @param Token $token The token that produced the error.
* @param int $code The code of the error.
*
* @throws ParserException Throws the exception, if strict mode is enabled.
*
* @return void
*/
public function error($msg = '', Token $token = null, $code = 0)
{
$error = new ParserException($msg, $token, $code);
if ($this->strict) {
throw $error;
}
$this->errors[] = $error;
}
}
}
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