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ADDDATE(date,INTERVAL expr type) ADDDATE(expr,days)
当被第二个参数的INTERVAL 格式激活后, ADDDATE() 就是DATE_ADD() 的同义词。相关函数SUBDATE() 则是DATE_SUB() 的同义词。对于INTERVAL 参数上的信息 ,请参见关于DATE_ADD() 的论述。
mysql> SELECT DATE_ADD('1998-01-02', INTERVAL 31 DAY);
-> '1998-02-02'
mysql> SELECT ADDDATE('1998-01-02', INTERVAL 31 DAY);
-> '1998-02-02'
若 days 参数只是整数值,则 MySQL 5.1 将其作为天数值添加至 expr 。
mysql> SELECT ADDDATE('1998-01-02', 31);
-> '1998-02-02'
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