Lexer - Solving ambiguity on function keywords #385
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Codecov ReportBase: 95.64% // Head: 95.66% // Increases project coverage by
Additional details and impacted files@@ Coverage Diff @@
## master #385 +/- ##
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+ Coverage 95.64% 95.66% +0.02%
- Complexity 2144 2156 +12
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Files 67 67
Lines 4548 4569 +21
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+ Hits 4350 4371 +21
Misses 198 198
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Note: When this gets merged please hard reset your master branch to phpmyadmin/sql-parser#master and use specific branch names for your PRs ;) |
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Yes, i've mistakenly used the master branch here, I will make sure to do this after this get merged |
iifawzi
changed the title
iifawzi
changed the title
src/Lexer.php
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| /** | ||
| * Resolves the ambiguity when dealing with the functions keywords. | ||
| * | ||
| * In SQL statements, the function keywords might be used as table names or columns names. | ||
| * To solve this ambiguity, the solution is to find the next token, excluding whitespaces and | ||
| * comments, right after the function keyword position. The function keyword is for sure used | ||
| * as column name or table name if the next token found is any of: | ||
| * | ||
| * - "FROM" (the FROM keyword like in "SELECT Country x, AverageSalary avg FROM..."); | ||
| * - "WHERE" (the WHERE keyword like in "DELETE FROM emp x WHERE x.salary = 20"); | ||
| * - "SET" (the SET keyword like in "UPDATE Country x, City y set x.Name=x.Name"); | ||
| * - "," (a comma separator like 'x,' in "UPDATE Country x, City y set x.Name=x.Name"); | ||
| * - "." (a dot separator like in "x.asset_id FROM (SELECT evt.asset_id FROM evt)". | ||
| * - "NULL" (when used as a table alias like in "avg.col FROM (SELECT ev.col FROM ev) avg"). | ||
| * | ||
| * This method will change the flag of the function keyword tokens when any of those | ||
| * condition above is true. Otherwise, the | ||
| * default flag (function keyword) will be kept. | ||
| * | ||
| * @return void | ||
| */ | ||
| private function solveAmbiguityOnFunctionKeywords() | ||
| { | ||
| $iBak = $this->list->idx; | ||
| $keywordFunction = Token::TYPE_KEYWORD | Token::FLAG_KEYWORD_FUNCTION; | ||
| while (($keywordToken = $this->list->getNextOfTypeAndFlag(Token::TYPE_KEYWORD, $keywordFunction)) !== null) { | ||
| $next = $this->list->getNext(); | ||
| if ( | ||
| ($next->type !== Token::TYPE_KEYWORD || ! in_array($next->value, ['FROM', 'SET', 'WHERE'], true)) | ||
| && ($next->type !== Token::TYPE_OPERATOR || ! in_array($next->value, ['.', ','], true)) | ||
| && ($next->value !== null) | ||
| ) { | ||
| continue; | ||
| } | ||
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| $keywordToken->type = Token::TYPE_NONE; | ||
| $keywordToken->flags = Token::TYPE_NONE; | ||
| $keywordToken->keyword = $keywordToken->value; | ||
| } | ||
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| $this->list->idx = $iBak; | ||
| } |
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I hope that I'm not missing any other cases. This way the keywords that represent functions names can be used freely as aliases or table names if the lexer detected that they're not being used as functions
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Can you squash your commits on the next push ? |
Signed-off-by: iifawzi <iifawzie@gmail.com>
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Since it affects the lexer, I agree that it's potentially risky. But still, the risks that this might introduce are minimal since we're only changing the token type in very specific cases, and otherwise it's kept as it's. Anyway, this's not an emergency yes, it can for sure wait for the next release. |
Pull-request: #385 Signed-off-by: William Desportes <williamdes@wdes.fr>
Fixing: #327 and #378
Signed-off-by: iifawzi iifawzie@gmail.com