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JDBC Driver: PreparedStatement counts ? placeholders inside SQL comments (regression since 0.1.36) #2835
Description
Activity
@polyglotAI-bot verify if there is an issue still. Add tests and minimum
@chernser verified on current
main: the reported defect no longer reproduces. A?inside a--or/* */comment is not counted as a parameter placeholder by either driver.The issue's own example reports 2 parameters (not 4):
-- filter by ? and ? SELECT * FROM my_table WHERE severity = ? AND status = ?
- jdbc-v2 — correct with all three backends (
JAVACC,ANTLR4,ANTLR4_PARAMS_PARSER), for the leading--, the leading/* */, a trailing--, and anINSERT ... VALUESpreceded by a comment. Fixed by Fix jdbc-v2: skip // comments and heredocs when scanning for ? placeholders #3010, Fix jdbc-v2: nest /* */ block comments in the ANTLR4 lexer #3022, Fix jdbc-v2: accept // line comments in the ANTLR4 lexer #3024, Fix jdbc-v2: reparse the parameters of a recovered ANTLR4 parse tree #3026 and Fix JDBC parser parameter counting for empty comments and SELECT * EXCEPT #3067; already covered byBaseSqlParserFacadeTestandPreparedStatementTest. - jdbc-v1 — correct as well.
JdbcParameterizedQuery.parse()skips--and/* */, verified both at the scanner level and end to end throughConnection#prepareStatementagainst ClickHouse 25.3.
jdbc-v1 had no test pinning this, so I opened #3154 with tests only (no production change): a
@DataProvideronJdbcParameterizedQueryTestcovering the comment forms, an empty comment, a;inside a comment, a nested block comment and a quoted-literal contrast case, plus an end-to-endPreparedStatementtest.One residual, jdbc-v1 only, not fixed: the v1 scan still counts a
?inside a//,#or#!comment and inside a heredoc ($$...$$,$tag$...$tag$) — forms the server does accept (confirmed against a live server). That is the same v1 parser gap as #3035 / #3037, which you closed as wontfix for v1 ("requires parser refactor - will be fixed in V2"), so #3154 proposes no v1 parser change and asserts none of those forms. jdbc-v2 handles all of them correctly.Suggest closing this issue once #3154 is merged, unless you want the v1 residual tracked separately.
- jdbc-v2 — correct with all three backends (
- added a commit that references this issue
on Oct 4, 2026
Problem
When a SQL query contains parameters inside comments (e.g.
-- filter by ${param}which gets replaced with
-- filter by ?before reaching the driver), the drivercounts those
?placeholders inside comments as actual parameters.This causes:
ArrayIndexOutOfBoundsException: Index 2 out of bounds for length 2Parameter index must between 1 and 2 but we got 3Example SQL (after parameter substitution by the application)
Driver sees 4 placeholders, application binds 2 values → exception.
Expected behavior
?inside SQL comments (--and/* */) should be ignored when countingPreparedStatement parameter placeholders.
Versions tested
All versions below have this bug:
com.clickhouse.jdbc.ClickHouseDriverandru.yandex.clickhouse.ClickHouseDriver)ClickHouseDriver,DriverV1, andjdbc_sql_parser=JAVACC/ANTLR4/ANTLR4_PARAMS_PARSER)Working version
clickhouse-jdbc-0.1.36(ru.yandex.clickhouse.ClickHouseDriver) correctly ignores?inside comments.Environment