Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Completing, refactoring and improving the WITH statements parser #363

Merged
merged 12 commits into from
Dec 29, 2021
53 changes: 45 additions & 8 deletions src/Statements/CreateStatement.php
Original file line number Diff line number Diff line change
Expand Up @@ -310,6 +310,17 @@ class CreateStatement extends Statement
*/
public $fields;

/**
* If `CREATE TABLE WITH`.
* If `CREATE TABLE AS WITH`.
* If `CREATE VIEW AS WITH`.
*
* Used by `CREATE TABLE`, `CREATE VIEW`
*
* @var WithStatement|null
*/
public $with;

/**
* If `CREATE TABLE ... SELECT`.
* If `CREATE VIEW AS ` ... SELECT`.
Expand Down Expand Up @@ -436,6 +447,13 @@ public function build()
. Expression::build($this->like);
}

if ($this->with !== null) {
return 'CREATE '
. OptionsArray::build($this->options) . ' '
. Expression::build($this->name) . ' '
. $this->with->build();
}

$partition = '';

if (! empty($this->partitionBy)) {
Expand Down Expand Up @@ -465,10 +483,17 @@ public function build()
. OptionsArray::build($this->entityOptions)
. $partition;
} elseif ($this->options->has('VIEW')) {
$builtStatement = '';
if ($this->select !== null) {
$builtStatement = $this->select->build();
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

do you know why it is reported non covered ?

Copy link
Contributor Author

@iifawzi iifawzi Dec 11, 2021

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

After 2 hours of investigation, It seems like it was always reporting false positive. it's A separate bug not related to the changes proposed in this PR, but it's now shown as uncovered because previously it wasn't in a separate branch:

return 'CREATE '
. OptionsArray::build($this->options) . ' '
. Expression::build($this->name) . ' '
. $fields . ' AS ' . ($this->select ? $this->select->build() : '')

The bug seems to be coming from this portion of code:

$token = $list->getNext(); // Skipping whitespaces and comments.
// Parsing columns list.
if (($token->type === Token::TYPE_OPERATOR) && ($token->value === '(')) {
--$list->idx; // getNext() also goes forward one field.
$this->fields = ArrayObj::parse($parser, $list);
++$list->idx; // Skipping last token from the array.
$list->getNext();
}
// Parsing the SELECT expression if the view started with it.
if (
$token->type === Token::TYPE_KEYWORD
&& $token->keyword === 'AS'
&& $list->tokens[$nextidx]->type === Token::TYPE_KEYWORD
&& $list->tokens[$nextidx]->value === 'SELECT'
) {
$list->idx = $nextidx;
$this->select = new SelectStatement($parser, $list);
}

You will notice that after parsing the array options if exists, we update the $list->idx by these two lines of code:

 ++$list->idx; // Skipping last token from the array. 
$list->getNext(); 

and that's totally fine, the issue is that in the code that follows, we're checking the keywords using the $token and the $nextidx but their old state, which was set before updating the idx after parsing the options.

if (
$token->type === Token::TYPE_KEYWORD
&& $token->keyword === 'AS'
&& $list->tokens[$nextidx]->type === Token::TYPE_KEYWORD
&& $list->tokens[$nextidx]->value === 'SELECT'
) {

so, we would need to update the $token and the $nextidx to their new values corresponding to the update that occured after parsing the options.

I will try to find sometime to fix it in the next weeks, but it has nothing to do with this PR.

} elseif ($this->with !== null) {
$builtStatement = $this->with->build();
}

return 'CREATE '
. OptionsArray::build($this->options) . ' '
. Expression::build($this->name) . ' '
. $fields . ' AS ' . ($this->select ? $this->select->build() : '')
. $fields . ' AS ' . $builtStatement
. (! empty($this->body) ? TokensList::build($this->body) : '') . ' '
. OptionsArray::build($this->entityOptions);
} elseif ($this->options->has('TRIGGER')) {
Expand Down Expand Up @@ -546,14 +571,22 @@ public function parse(Parser $parser, TokensList $list)
if (($token->type === Token::TYPE_KEYWORD) && ($token->keyword === 'SELECT')) {
/* CREATE TABLE ... SELECT */
$this->select = new SelectStatement($parser, $list);
} elseif ($token->type === Token::TYPE_KEYWORD && ($token->keyword === 'WITH')) {
/* CREATE TABLE WITH */
$this->with = new WithStatement($parser, $list);
} elseif (
($token->type === Token::TYPE_KEYWORD) && ($token->keyword === 'AS')
&& ($list->tokens[$nextidx]->type === Token::TYPE_KEYWORD)
&& ($list->tokens[$nextidx]->value === 'SELECT')
) {
/* CREATE TABLE ... AS SELECT */
$list->idx = $nextidx;
$this->select = new SelectStatement($parser, $list);
if ($list->tokens[$nextidx]->value === 'SELECT') {
/* CREATE TABLE ... AS SELECT */
$list->idx = $nextidx;
$this->select = new SelectStatement($parser, $list);
} elseif ($list->tokens[$nextidx]->value === 'WITH') {
/* CREATE TABLE WITH */
$list->idx = $nextidx;
$this->with = new WithStatement($parser, $list);
}
} elseif ($token->type === Token::TYPE_KEYWORD && $token->keyword === 'LIKE') {
/* CREATE TABLE `new_tbl` LIKE 'orig_tbl' */
$list->idx = $nextidx;
Expand Down Expand Up @@ -711,10 +744,14 @@ public function parse(Parser $parser, TokensList $list)
$token->type === Token::TYPE_KEYWORD
&& $token->keyword === 'AS'
&& $list->tokens[$nextidx]->type === Token::TYPE_KEYWORD
&& $list->tokens[$nextidx]->value === 'SELECT'
) {
$list->idx = $nextidx;
$this->select = new SelectStatement($parser, $list);
if ($list->tokens[$nextidx]->value === 'SELECT') {
$list->idx = $nextidx;
$this->select = new SelectStatement($parser, $list);
} elseif ($list->tokens[$nextidx]->value === 'WITH') {
++$list->idx;
$this->with = new WithStatement($parser, $list);
}
}

// Parsing all other tokens
Expand Down
10 changes: 10 additions & 0 deletions src/Statements/InsertStatement.php
Original file line number Diff line number Diff line change
Expand Up @@ -98,6 +98,14 @@ class InsertStatement extends Statement
*/
public $select;

/**
* If WITH CTE is present
* holds the WithStatement.
*
* @var WithStatement|null
*/
public $with;

/**
* If ON DUPLICATE KEY UPDATE clause is present
* holds the SetOperation.
Expand Down Expand Up @@ -210,6 +218,8 @@ public function parse(Parser $parser, TokensList $list)
$this->set = SetOperation::parse($parser, $list);
} elseif ($token->keyword === 'SELECT') {
$this->select = new SelectStatement($parser, $list);
} elseif ($token->keyword === 'WITH') {
$this->with = new WithStatement($parser, $list);
} else {
$parser->error('Unexpected keyword.', $token);
break;
Expand Down
174 changes: 137 additions & 37 deletions src/Statements/WithStatement.php
Original file line number Diff line number Diff line change
Expand Up @@ -66,26 +66,34 @@ final class WithStatement extends Statement
*/
public function parse(Parser $parser, TokensList $list)
{
++$list->idx; // Skipping `WITH`.

// parse any options if provided
$this->options = OptionsArray::parse($parser, $list, static::$OPTIONS);
++$list->idx;

/**
* The state of the parser.
*
* Below are the states of the parser.
*
* 0 ---------------- [ name ] -----------------> 1
* 1 -------------- [( columns )] AS ----------------> 2
* 2 ------------------ [ , ] --------------------> 0
*
* 1 ------------------ [ ( ] ------------------> 2
*
* 2 ------------------ [ AS ] -----------------> 3
*
* 3 ------------------ [ ( ] ------------------> 4
*
* 4 ------------------ [ , ] ------------------> 1
*
* 4 ----- [ SELECT/UPDATE/DELETE/INSERT ] -----> 5
*
* @var int
*/
$state = 0;
$wither = null;

++$list->idx; // Skipping `WITH`.

// parse any options if provided
$this->options = OptionsArray::parse($parser, $list, static::$OPTIONS);
++$list->idx;

for (; $list->idx < $list->count; ++$list->idx) {
/**
* Token parsed at this moment.
Expand All @@ -99,57 +107,149 @@ public function parse(Parser $parser, TokensList $list)
continue;
}

if ($token->type === Token::TYPE_NONE) {
if ($state === 0) {
if ($token->type !== Token::TYPE_NONE) {
$parser->error('The name of the CTE was expected.', $token);
break;
}

$wither = $token->value;
$this->withers[$wither] = new WithKeyword($wither);
$state = 1;
continue;
}

if ($state === 1) {
if ($token->value === '(') {
} elseif ($state === 1) {
if ($token->type === Token::TYPE_OPERATOR && $token->value === '(') {
$this->withers[$wither]->columns = Array2d::parse($parser, $list);
continue;
}

if ($token->keyword === 'AS') {
++$list->idx;
$state = 2;
continue;
} elseif ($token->type === Token::TYPE_KEYWORD && $token->keyword === 'AS') {
$state = 3;
} else {
$parser->error('Unexpected token.', $token);
break;
}
} elseif ($state === 2) {
if ($token->value === '(') {
++$list->idx;
$subList = $this->getSubTokenList($list);
if ($subList instanceof ParserException) {
$parser->errors[] = $subList;
continue;
}
if (! ($token->type === Token::TYPE_KEYWORD && $token->keyword === 'AS')) {
$parser->error('AS keyword was expected.', $token);
break;
}

$subParser = new Parser($subList);
$state = 3;
} elseif ($state === 3) {
$idxBeforeGetNext = $list->idx;

if (count($subParser->errors)) {
foreach ($subParser->errors as $error) {
$parser->errors[] = $error;
}
// We want to get the next non-comment and non-space token after $token
// therefore, the first getNext call will start with the current $idx which's $token,
// will return it and increase $idx by 1, which's not guaranteed to be non-comment
// and non-space, that's why we're calling getNext again.
$list->getNext();
$nextKeyword = $list->getNext();

if (! ($token->value === '(' && ($nextKeyword && $nextKeyword->value === 'SELECT'))) {
$parser->error('Subquery of the CTE was expected.', $token);
$list->idx = $idxBeforeGetNext;
break;
}

// Restore the index
$list->idx = $idxBeforeGetNext;

++$list->idx;
$subList = $this->getSubTokenList($list);
if ($subList instanceof ParserException) {
$parser->errors[] = $subList;
break;
}

$subParser = new Parser($subList);

if (count($subParser->errors)) {
foreach ($subParser->errors as $error) {
$parser->errors[] = $error;
}

$this->withers[$wither]->statement = $subParser;
continue;
break;
}

// There's another WITH expression to parse, go back to state=0
$this->withers[$wither]->statement = $subParser;

$state = 4;
} elseif ($state === 4) {
if ($token->value === ',') {
$list->idx++;
// There's another WITH expression to parse, go back to state=0
$state = 0;
continue;
}

// No more WITH expressions, we're done with this statement
if (
$token->type === Token::TYPE_KEYWORD && (
$token->value === 'SELECT'
|| $token->value === 'INSERT'
|| $token->value === 'UPDATE'
|| $token->value === 'DELETE'
)
) {
$state = 5;
--$list->idx;
continue;
}

$parser->error('An expression was expected.', $token);
break;
} elseif ($state === 5) {
/**
* We need to parse all of the remaining tokens becuase mostly, they are only the CTE expression
* which's mostly is SELECT, or INSERT, UPDATE, or delete statement.
* e.g: INSERT .. ( SELECT 1 ) SELECT col1 FROM cte ON DUPLICATE KEY UPDATE col_name = 3.
* The issue is that, `ON DUPLICATE KEY UPDATE col_name = 3` is related to the main INSERT query
* not the cte expression (SELECT col1 FROM cte) we need to determine the end of the expression
* to parse `ON DUPLICATE KEY UPDATE` from the InsertStatement parser instead.
*/

// Index of the last parsed token by default would be the last token in the $list, because we're
// assuming that all remaining tokens at state 4, are related to the expression.
$idxOfLastParsedToken = $list->count - 1;
// Index before search to be able to restore the index.
$idxBeforeSearch = $list->idx;
// Length of expression tokens is null by default, in order for the $subList to start
// from $list->idx to the end of the $list.
$lengthOfExpressionTokens = null;

if ($list->getNextOfTypeAndValue(Token::TYPE_KEYWORD, 'ON')) {
// (-1) because getNextOfTypeAndValue returned ON and increased the index.
$idxOfOn = $list->idx - 1;
// Index of the last parsed token will be the token before the ON Keyword, therefore $idxOfOn - 1.
$idxOfLastParsedToken = $idxOfOn - 1;
// The length of the expression tokens would be the position of
$lengthOfExpressionTokens = $idxOfOn - $idxBeforeSearch;
}

// Restore the index
$list->idx = $idxBeforeSearch;

$subList = new TokensList(array_slice($list->tokens, $list->idx, $lengthOfExpressionTokens));
$subParser = new Parser($subList);
if (count($subParser->errors)) {
foreach ($subParser->errors as $error) {
$parser->errors[] = $error;
}
}

$list->idx = $idxOfLastParsedToken;
break;
}
}

// 5 is the only valid end state
if ($state !== 5) {
/**
* Token parsed at this moment.
*
* @var Token
*/
$token = $list->tokens[$list->idx];

$parser->error('Unexpected end of the WITH CTE.', $token);
}

--$list->idx;
}

Expand Down
Loading