db2 10 往一个测试表里插入空字符串'',但是查询出来后,该字段为null...答:insert into tab values(1,'JACK','0001','2000');insert into tab values(2,'TOM','0002','');insert into tab values(3,'LUCY','0003','3000');insert into tab values(4,'JAME','0004','');insert into tab values(4,'KIM','0005',null);db2 => select * from tab;select ...