1702
MariaDBWARNINGCriticalDDLHIGH confidence
Legacy SQL syntax was automatically converted to the new syntax
Production Risk
Low — warning only; statement executes.
What this means
MySQL silently converted deprecated SQL syntax to the current equivalent. While the statement succeeds, the legacy syntax should be updated to avoid failures in future versions.
Why it happens
- 1Using old JOIN syntax such as comma-join without explicit ON clause.
- 2Other deprecated DDL constructs accepted for backwards compatibility.
How to reproduce
trigger — this will error
trigger — this will error
-- Example: using old-style implicit join. SELECT * FROM t1, t2 WHERE t1.id = t2.id;
expected output
Warning (Code 1702): Statement converted from legacy syntax.
Fix
Rewrite using explicit JOIN syntax
Rewrite using explicit JOIN syntax
SELECT * FROM t1 INNER JOIN t2 ON t1.id = t2.id;
Why this works
Explicit JOIN syntax is standard SQL and will not trigger conversion warnings.
What not to do
✕
Sources
Official documentation ↗
MySQL 8.0 — 1702 ER_WARN_LEGACY_SYNTAX_CONVERTED
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