1.确保编码是:
[mysqld] character-set-server=utf8mb4
2.确保参数 ngram_token_size=1,如果参数修改过，并且原来有全文索引，则需要执行"ALTER TABLE your_table DROP INDEX idx_fulltext, ADD FULLTEXT INDEX idx_fulltext (your_column) WITH PARSER ngram;"
3.CREATE FULLTEXT INDEX idx_fulltext ON your_table (your_column) WITH PARSER ngram;
