题解 | #将所有to_date为9999-01-01的全部更新为NULL#
将所有to_date为9999-01-01的全部更新为NULL
http://www.nowcoder.com/practice/859f28f43496404886a77600ea68ef59
update titles_test set to_date=null,from_date='2001-01-01'where to_date='9999-01-01'
update table_name set column_name="value" where column="condition"