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### What problem does this PR solve? Issue Number: None Related PR: None Problem Summary: A comment on a VARIANT predefined field is printed without SQL-literal escaping, so the output of SHOW CREATE TABLE cannot be replayed when the comment contains a quote: ```sql CREATE TABLE t (id INT, v VARIANT<'price':INT COMMENT "O'Reilly">) ...; SHOW CREATE TABLE t; -- v variant<'price':int COMMENT 'O'Reilly', ...> -- replaying it fails: no viable alternative at input 'variant<'price':int COMMENT 'O'Reilly' ``` Root cause: both `catalog.VariantField.toSql` (used by SHOW CREATE TABLE through `Column.toSql`) and `nereids.types.VariantField.toSql` wrap the raw comment in single quotes. The parser side was also inconsistent with the rest of the grammar: `visitVariantSubColType` only strips the outer quotes and unescapes backslashes, so a doubled quote such as `'O''Reilly'` is stored as `O''Reilly`. Fix, following how STRUCT field comments are already handled: - print the comment with `SqlUtils.quoteStringLiteral` / `SqlLiteralUtils.quoteStringLiteral`; - parse it with `SqlLiteralUtils.parseStringLiteral`, like `visitComplexColType` does. After the fix the comment above is printed as `COMMENT "O'Reilly"`, and quotes, doubled quotes and backslashes survive a SHOW CREATE TABLE → CREATE TABLE round trip. ### Release note Fix SHOW CREATE TABLE output that could not be replayed when a VARIANT predefined field comment contains quotes or backslashes. ### Check List (For Author) - Test: Regression test (variant_p0/predefine/test_variant_predefine_comment_escape) / Unit Test (TypeTest#testVariantFieldCommentToSqlRoundTrip) - Behavior changed: Yes. SHOW CREATE TABLE prints predefined field comments as double-quoted, escaped literals; a doubled quote inside a comment is now stored as a single quote, like column and STRUCT field comments. - Does this need documentation: No Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
eldenmoon
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924060929,
englefly,
morrySnow and
starocean999
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September 18, 2026 09:38
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What problem does this PR solve?
Issue Number: None
Related PR: None
Problem Summary:
A comment on a VARIANT predefined field is printed without SQL-literal escaping, so the output of SHOW CREATE TABLE cannot be replayed when the comment contains a quote:
Root cause: both
catalog.VariantField.toSql(used by SHOW CREATE TABLE throughColumn.toSql) andnereids.types.VariantField.toSqlwrap the raw comment in single quotes. The parser side was also inconsistent with the rest of the grammar:visitVariantSubColTypeonly strips the outer quotes and unescapes backslashes, so a doubled quote such as'O''Reilly'is stored asO''Reilly.Fix, following how STRUCT field comments are already handled:
SqlUtils.quoteStringLiteral/SqlLiteralUtils.quoteStringLiteral;SqlLiteralUtils.parseStringLiteral, likevisitComplexColTypedoes.After the fix the comment above is printed as
COMMENT "O'Reilly", and quotes, doubled quotes and backslashes survive a SHOW CREATE TABLE → CREATE TABLE round trip.Release note
Fix SHOW CREATE TABLE output that could not be replayed when a VARIANT predefined field comment contains quotes or backslashes.
Check List (For Author)
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