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ClickHouse: tuple element access followed by a field changes meaning after round-trip #2599
Description
Description
With ClickHouseDialect, a tuple element access followed by a named field prints without spaces around the second dot. The printed SQL parses back as a different query, with no error.
Reproduction
use sqlparser::dialect::ClickHouseDialect;
use sqlparser::parser::Parser;
let sql = "SELECT t.1.name";
let ast = Parser::parse_sql(&ClickHouseDialect {}, sql).unwrap();
let printed = ast[0].to_string();
println!("{printed}"); // SELECT t . 1.name
let reparsed = Parser::parse_sql(&ClickHouseDialect {}, &printed).unwrap();
println!("{}", reparsed[0]); // SELECT t . 1. AS name| Step | Result |
|---|---|
| Input | SELECT t.1.name |
| Parsed | CompoundFieldAccess { root: t, access_chain: [Dot(1), Dot(name)] } (correct) |
| Printed | SELECT t . 1.name |
| Re-parsed | SELECT t . 1. AS name: the number 1. with alias name |
Expected
The printed output keeps the access chain, e.g. SELECT t . 1 . name, and parses back to the same AST.
Context
ClickHouse's lexer tokenizes t.1.name as t . 1 . name (see the "chained tuple access" disambiguation in src/Parsers/Lexer.cpp), so the initial parse is correct and only Display is wrong.
Follow-up to #2574 (tuple element access). Found with the fuzz_parse_roundtrip fuzz target.
Activity
princejain756 commentedon Oct 21, 2026
Verified fixed on current main (post-#2675, which added the
prev_is_numberhandling inCompoundFieldAccessdisplay).t.1.name,t.1.name.2,t.1.2.x, and(t.1).nameall round-trip with identical ASTs now. This can be closed.s5dsn-eqee commentedon Oct 22, 2026
Thank you @princejain756
princejain756 commentedon Oct 22, 2026
Happy to help. #2675 covers the reparsing side; the report can probably close.