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Unknown Collation: utf8mb4_0900_ai_ci

A MySQL 8 dump won't import into MariaDB or MySQL 5.7 because they don't recognise the utf8mb4_0900_ai_ci collation.

Common causes

  • • Exported from MySQL 8 (0900 = Unicode 9.0 collation)
  • • Importing into MariaDB or MySQL 5.7
  • • Target server has no matching collation name

Best fixes

  • • Replace utf8mb4_0900_ai_ci with utf8mb4_unicode_ci
  • • Re-export with a compatible default character set
  • • Convert MyISAM tables to InnoDB if 'key too long' follows

Quick fix

Split the dump into smaller parts to reduce statement size and import time.

Open SQLSplit

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