1989
MariaDBERRORNotableQueryHIGH confidence
Unknown HANDLER statement
Production Risk
Low — statement is rejected; no data is modified.
What this means
A HANDLER ... READ or HANDLER ... CLOSE was issued for a handler name that was not opened with HANDLER ... OPEN, or the handler was already closed.
Why it happens
- 1HANDLER READ issued before HANDLER OPEN.
- 2Handler name misspelled in HANDLER READ or HANDLER CLOSE.
- 3Handler was implicitly closed (e.g. by DDL on the table) before the read.
How to reproduce
trigger — this will error
trigger — this will error
HANDLER nonexistent_handler READ FIRST;
expected output
ERROR 1989 (42000): Unknown HANDLER 'nonexistent_handler'.
Fix
Open the handler before reading
Open the handler before reading
HANDLER my_table OPEN AS h1; HANDLER h1 READ FIRST; HANDLER h1 CLOSE;
Why this works
A HANDLER must be explicitly opened and its alias used consistently.
What not to do
✕
Sources
Official documentation ↗
MySQL 8.0 — 1989 ER_UNKNOWN_STMT_HANDLER
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