TIMESTAMP columns are NOT NULL by default, cannot contain NULL values, and assigning NULL assigns the current timestamp. However, a TIMESTAMP column can be permitted to contain NULL by declaring it with the NULL attribute. In this case, the default value also becomes NULL unless overridden with a DEFAULT clause that specifies a different default value. DEFAULT NULL can be used to explicitly specify NULL as the default value. (For a TIMESTAMP column not declared with the NULL attribute, DEFAULT NULL is illegal.) If a TIMESTAMP column permits NULL values, assigning NULL sets it to NULL, not to the current timestamp.

你在创建表的时候，直接 AUDITTIME TIMESTAMP null default NULL comment ‘审核时间’, 不行？