EC
1665
MySQLERRORNotableSchemaHIGH confidence

Unknown ALTER TABLE LOCK value

Production Risk

Low — the ALTER is rejected; no data change.

What this means

The LOCK clause in an ALTER TABLE statement specifies an unrecognised lock mode.

Why it happens
  1. 1A typo or unsupported value was used in LOCK=.
How to reproduce
trigger — this will error
trigger — this will error
ALTER TABLE t ADD COLUMN x INT, LOCK=PARTIAL;

expected output

ERROR 1665 (HY000): Unknown LOCK 'PARTIAL'.

Fix

Use a valid LOCK value

Use a valid LOCK value
ALTER TABLE t ADD COLUMN x INT, LOCK=NONE;
-- Valid values: DEFAULT, NONE, SHARED, EXCLUSIVE

Why this works

Using a supported lock level resolves the error.

Sources
Official documentation ↗

MySQL 8.0 — 1665 ER_UNKNOWN_ALTER_LOCK

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