Keywords are words that have significance in SQL. Certain keywords, such as SELECT, DELETE, or BIGINT, are reserved and require special treatment for use as identifiers such as table and column names. This may also be true for the names of built-in functions. Nonreserved keywords are permitted as identifiers without quoting. 参考:https://dev.mysql.com/doc/refman/5.5/en/keywords.html 翻译一下: 也就是说在Mysql中一些保留字在用作表名,列名的时候需要使用倒引号`这种标识符来特殊的标识.注意只是保留字需要特殊,不包括一般的关键字,比如BEGIN和BEGIN是关键字但不保留，因此使用它们作为标识符的使用不需要倒引用。