SQL问题（update）， 请大神帮忙解决！

update loan set keyinfostate = ? and applyModifyContent = ? where id = ?

报的错误是：Data truncation: Column set to default value; NULL supplied to NOT NULL column 'keyinfostate' at row 1

已解决

要使用这样的update格式：
update loan set keyinfostate = 'ABC ' where id = 'AAA';
update loan set applyModifyContent = 'DEF' where id = 'AAA';

select fyp from b where wrcvdate between 2013-08-01 and 2013-08-31

非空的列却给了空值