fix(postgres): support UNIQUE NULLS NOT DISTINCT constraint syntax#839
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NQPhuc merged 2 commits intoholistics:masterfrom Mar 9, 2026
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PostgreSQL 15 introduced `NULLS NOT DISTINCT` for unique constraints, allowing NULL values to be treated as equal. The parser grammar was missing this optional clause in the `constraintelem` rule, causing a crash when importing SQL dumps containing this syntax. Fixes holistics#838 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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While waiting for this PR to be merged, I've published a temporary fork to npm: Packages: Version: Usage# Using npx
npx -p @frenzzy/dbml-cli@nulls-not-distinct sql2dbml schema.sql --postgres -o schema.dbml
# Or install as dependency
npm install @frenzzy/dbml-cli@nulls-not-distinctThese are drop-in replacements until the official packages are updated. |
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PR: Bug Fix 🐛
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Summary
Fix
sql2dbmlcrash when parsing PostgreSQL dumps containingUNIQUE NULLS NOT DISTINCTconstraints (introduced in PostgreSQL 15).Root cause: The
constraintelemgrammar rule was missing the optionalnulls_distinct?clause before the column list in theUNIQUEalternative. This caused the ANTLR parser to produce a null node for the column list, leading toCannot read properties of null (reading 'accept')invisitConstraintelem.Fix: Added
nulls_distinct?(which already existed in the grammar forCREATE INDEX) to theUNIQUEbranch ofconstraintelem. TheNULLS NOT DISTINCTmodifier is gracefully ignored in the DBML output, falling back to a regularUNIQUEconstraint — consistent with how DBML currently handles index-levelNULLS NOT DISTINCT.Fixes #838
Changes
PostgreSQLParser.g4: Addednulls_distinct?to theUNIQUEbranch ofconstraintelem(1-line change)PostgreSQLParser.jsandPostgreSQLParser.interpvia ANTLR 4.13.2nulls_not_distinct.in.sql/nulls_not_distinct.out.dbml)Test plan
nulls_not_distincttest case passespg_dumpoutput containingUNIQUE NULLS NOT DISTINCT