feat: match empty column when in entityCollecting context#457
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JackWang032 wants to merge 17 commits into
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feat: match empty column when in entityCollecting context#457JackWang032 wants to merge 17 commits into
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* feat: support queryResult and derived table entities collecting * feat: support query result and derived table entity collecting * test: enhance hive and spark entity collect test case * fix: remove _ctx and add tokenIndex into position * fix: rename declareType COMMON to LITERAL * fix: optimize entity collector and update grammar * test: add derived table and query result entities test case * fix: remove isCaretInDerivedTableStmt and set default isAccessible to null * fix: update _caretStmt docs * test: add isAccessible test case * fix: skip _caretStmt ts check * docs: update README to include additional entity information * test: fix create view test case * fix: import from error sql module * test: update entity collection tests * fix: remove unused type
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额外需要注意：非保留关键字可能会被识别为别名，需要做些特殊处理手段 |
Cythia828
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Mar 24, 2026
- Add shouldMatchEmpty() method to SQLParserBase - Add emptyColumn rule to PostgreSQL grammar - Add exitTarget_empty method to entity collector - Update grammar files to remove semantic predicates - Update tests to expect empty column entities - Regenerate all parser files Fixes: DTStack#457
Cythia828
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May 19, 2026
…lecting context (#467) Co-authored-by: zhaoge <>
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当输入的SQL不完整时，特别是没有输入字段或者输入了表名
table1.<empty>时，会导致语法解析错误恢复失败，最终的语法解析树无法作为实体收集的参考模板， 实体收集失败。如在MySQL中输入
SELECT t1. FROM t1，没法收集到任何实体，那么就没法去提供对应的补全我们已在 grammar 中对
columnName添加了{this.shouldMatchEmpty()}?语义谓词分支的支持，使在实体收集时能够匹配空字段，但这仅能覆盖一小部分情况，当where、order by、join on等场景时（会匹配 expression ）无效，并且输入点时也无法命中。语义谓词：语义谓词是 ANTLR4 中将语法规则与自定义代码逻辑结合的核心机制，用于在语法解析过程中动态控制规则的匹配行为
一般来说 grammar 中将字段拆分成了
columnName与columnNamePath两个规则，columnName在select item中匹配，columnNamePath在表达式中匹配。目前有两种方法利用语义谓词解决该问题：
方案一
为
columnNamePath也添加空字段的语义谓词分支，但该方式会导致比较多的语法校验单测失败（语义谓词分支会影响预测，即使该语义谓词分支没有匹配上），影响范围也没法确定。目前PGSQL尝试使用了该方式。方案二
最小化改动原则（当前尝试的方式），在具体规则(where、 order by、 join on等)后添加语义谓词，基本不会导致现有的单测报错。
如果采用方案一，其表现效果很好，但需要深入分析下语义谓词对antlr4 预测、错误恢复等阶段的影响，避免其影响到非实体收集上下文时的功能。
如果采用方案二，需要处理很多不同 expression下的场景，如需要处理
join ... on t1.id = t2.id中 比较操作符=可能会嵌套递归的情况使用语义谓词后语法解析树基本能保证完整
Preview地址 https://jackwang032.github.io/monaco-sql-languages/