Fix jdbc-v2: lex heredoc strings as a single literal in the JavaCC parser - #3030
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Fix jdbc-v2: lex heredoc strings as a single literal in the JavaCC parser#3030polyglotAI-bot wants to merge 1 commit into
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…rser The JavaCC grammar had no heredoc token, so the body of `$$...$$` / `$tag$...$tag$` was lexed as ordinary SQL. A body character with no standalone token (`!`, `&`, `|`, `~`) raised a TokenMgrException, which is not a ParseException and so escaped dataClause()'s recovery, leaving the whole statement classified as UNKNOWN: an INSERT was reported as a result-set-bearing statement with no table name and no values-list positions. Fixes: #3029
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This was referenced Aug 4, 2026
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Description
Fixes #3029.
The
jdbc-v2JavaCC grammar (the default parser,jdbc_sql_parser=JAVACC) has no heredoc token, so the body of a$$...$$/$tag$...$tag$literal is lexed as ordinary SQL —$$aeven matchesIDENTIFIER. A body character that is not a valid standalone token (!,&,|,~) therefore raises aTokenMgrException, which is not aParseException, so the recovery indataClause()never sees it. It escapes toClickHouseSqlParser.parse, whosecatch (Exception)discards the parse result and leaves the pre-initializedStatementType.UNKNOWNstatement: anINSERTis reported asisInsert() == false,isHasResultSet() == true,hasErrors() == true, with no table name, no values-list positions and no value groups — which silently disables the batch values template, the table-name based paths (e.g. the beta RowBinary writer) and theexecute()/getMetaData()routing, and logs a parse warning. The server accepts all of these statements, and both ANTLR4 backends already classify them correctly.The fix teaches the lexer about heredocs (the grammar's own
FIXMEindataClause()flagged the missing lexical state) so a heredoc is a single string literal, as it is on the server.Changes
jdbc-v2/src/main/javacc/ClickHouseSqlParser.jjHEREDOC_LITERALtoken:$tag$body$tag$with an optional[a-zA-Z0-9_]tag. It is declared beforeIDENTIFIERso that on an equal-length match (e.g.$$a$$, whichIDENTIFIERalso matches because$is in both its first and continuation sets) the heredoc wins.$and the opening/closing tags are not required to be equal. An unterminated tag ($foo$bar) stays the longerIDENTIFIERmatch, i.e. existing behavior is preserved — and that is also how the server reads it (SELECT $foo$barfails withUNKNOWN_IDENTIFIER '$foo$bar', not an unterminated-heredoc error).literal()accepts the new token, which makes a heredoc usable wherever a string literal is a value — this reaches bothcolumnExpr()andanyColumnExpr(), so VALUES lists, select lists and the "not interested" statements are all covered.CHANGELOG.md: entry under0.11.0-rc1→ Bug Fixes.No public API change; no configuration change. The change is additive at the lexer level: input that parsed before still parses, and input that previously raised a lexer error is now accepted.
Test
jdbc-v2/src/test/java/com/clickhouse/jdbc/internal/BaseSqlParserFacadeTest.java— the shared parser-facade suite, so the cases run against all three backends (JAVACC,ANTLR4,ANTLR4_PARAMS_PARSER):testHeredocStatements(@DataProvider) assertshasErrors,isInsert,isHasResultSet, the extracted table and the exact values-list substring (sliced from the caller's SQL via the reported start/stop positions) for: each offending body character (!,&,|,~,@), the tagged form, a body with whitespace, parentheses and commas in a body (so a shifted values list would be caught), two heredocs in one values list, and a heredoc in aSELECTlist.SELECT $foo$bar FROM t) and a$inside an identifier (SELECT a$b FROM t) keep parsing as identifiers, and a quoted'a!b'literal keeps its existing handling.testHeredocStatementsJavaCcOnlycovers two bodies the ANTLR4 grammars do not accept yet (a;inside the body — which must not split the statement — and an empty$$$$body), guarded with the file's existingjavaCcBackendpattern.Verification: the new cases fail on
main(9 failures for the JavaCC backend) and pass with the fix; the fulljdbc-v2unit suite is green (1343 tests), including the ANTLR4 backends, with no existing test modified.Note on scope: the character-scanning placeholder pass (
parseParameters) is separately not heredoc-aware — that is #3009 / PR #3010 and is deliberately untouched here. The legacyclickhouse-jdbc(v1) module carries a copy of this grammar with the same missing token; it is not changed in this PR.Pre-PR validation gate
main@ 1a11756, passes with the fix)jdbc-v2unit suite green)AGENTS.md(single logical change, targeted Maven runs,@DataProviderinstead of near-identical methods, no issue numbers inside test code, CHANGELOG updated)docs/features.mdchange (no feature added, removed or intentionally changed)