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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"sqlite virtual table silently returns empty rows for unavailable join parameters","articleBody":"### Version\n\nmain\n\n### Platform\n\n```text\nAll\n```\n\n### Subsystem\n\nsqlite\n\n### What steps will reproduce the bug?\n\n```js\nimport { DatabaseSync } from 'node:sqlite';\n\nconst db = new DatabaseSync(':memory:');\n\ndb.createModule('m', {\n  columns: [\n    { name: 'value', type: 'INTEGER' },\n    { name: 'a', type: 'INTEGER', hidden: true },\n  ],\n  *rows(a) { if (a !== null) yield [a]; },\n});\n\ndb.exec('CREATE TABLE t (a INTEGER)');\ndb.exec('INSERT INTO t VALUES (1), (2), (3)');\n\nconsole.log(db.prepare('SELECT DISTINCT * FROM m(t.a) JOIN t ON t.a = m.a').all());\n```\n\n### How often does it reproduce? Is there a required condition?\n\nAlways\n\n### What is the expected behavior? Why is that the expected behavior?\n\nPer SQLite's [Enforcing Required Parameters On Table-Valued Functions](https://www.sqlite.org/vtab.html#enforcing_required_parameters_on_table_valued_functions), `xBestIndex()` must return `SQLITE_CONSTRAINT` when a parameter has an EQ constraint whose `usable` flag is false, so the planner picks an ordering where the parameter is available. Cost estimates alone cannot enforce parameter dependencies.\n\n### What do you see instead?\n\n`rows()` is called with `null` and the query returns `[]`. `xBestIndex()` skips constraints with `usable == false`, accepts the unconstrained plan, and `xFilter()` passes `Null(isolate)`.\n\n### Additional information\n\n_No response_","author":{"url":"https://github.com/trivikr","@type":"Person","name":"trivikr"},"datePublished":"2026-09-22T23:22:25Z","url":"https://github.com/nodejs/node/issues/66214"}