无法更新postgres中的时间戳

Question

这是我正在使用的查询

update table_x set is_resolved = true and updated_on='2015-02-06 13:51:04.980294' 
where ps='XXX' and pi='YYY' and is_resolved is false and activity_type='ZZZ'

运行更新的结果是：

"Query returned successfully: one row affected, 22 ms execution time."

当我这样做时

select * from table_x where where ps='XXX' and pi='YYY'  and activity_type='ZZZ'

我仍然看到is_resolved或updated_on值未更改