fix: resolve double LIMIT bug in SQL pagination wrapping#154
Merged
debba merged 1 commit intoTabularisDB:mainfrom May 4, 2026
Merged
fix: resolve double LIMIT bug in SQL pagination wrapping#154debba merged 1 commit intoTabularisDB:mainfrom
debba merged 1 commit intoTabularisDB:mainfrom
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The `strip_limit_offset` and `extract_user_limit` helpers used naive
`rfind("LIMIT")` / `rfind("OFFSET")` which matched the keyword as a
substring of table names (e.g. `tapp_appointment_message_event_limit`),
string literals, or quoted identifiers — producing corrupted pagination
queries.
Replace the raw string search with a quote-and-bracket-aware SQL
tokenizer (`tokenize_sql`) that treats single-quoted strings,
double-quoted identifiers, backtick-quoted identifiers, and
parenthesized groups as opaque tokens. `strip_limit_offset` and
`extract_user_limit` now scan backward over tokens so only standalone
`LIMIT` / `OFFSET` keywords are matched.
Also update MCP `run_query` tool:
- Accept an optional `limit` parameter (default 100)
- Document that user LIMIT clauses in the SQL are respected
Add 11 new test cases covering table names containing "limit", quoted
identifiers, string literals with SQL keywords, and subqueries.
Made-with: Cursor
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Thanks for PR, I will check it ASAP |
Collaborator
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i will merge it, thanks |
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Summary
extract_order_by/remove_order_byused naiverfind("ORDER BY")that captured trailing LIMIT/OFFSET clauses, producing double LIMIT syntax errors when the pagination layer appended its own LIMIT.extract_trailing_clauses+build_paginated_query) indrivers/common.rsthat correctly separates ORDER BY, LIMIT, and OFFSET from the base query.run_querynow accepts an optionallimitparameter and respects user-specified LIMIT clauses (takesmin(user_limit, page_size)).Bug details
When a user (or AI agent via MCP) ran a query like:
The old code produced invalid SQL:
The double
LIMIT 10 LIMIT 101is a syntax error on all database engines.Changes
src-tauri/src/drivers/common.rstokenize_sql,extract_trailing_clauses,build_paginated_query+ 18 unit testssrc-tauri/src/drivers/postgres/mod.rssrc-tauri/src/drivers/mysql/mod.rssrc-tauri/src/drivers/sqlite/mod.rssrc-tauri/src/mcp/mod.rslimitparam torun_query, use configurable max_rowsTest plan
cargo test --lib drivers::common::tests) covering:tapp_appointment_message_event_limit)build_paginated_querywith user limit smaller/larger than page_sizecargo test --libpasses (115/117 pass; 2 pre-existing failures inupdater::testsunrelated to this change)cargo buildsucceeds with no warnings