在线有请问大家下面这个语句怎么写？？

[Fibona]

我现在两个表，一个表user_self_assessmentt中有如下字段：testid,userid ,testdate
另一个表question_answer 中：id,testid,questionid ,answer(其中的testid为test表的外键）
现在要求用一条语句选出两个表中的数据，即选出所有用户的所有测试的成绩，及日期
我的语句如下：select user_self_assessment.testid,user_self_assessment.userid,user_self_assessment.testdate, question_answer.questionid,question_answer.answer from user_self_assessment inner join question_answer where question_answer.testid=user_self_assessment.testid
有请各位老大帮帮忙，谢谢各位？

[Fibona]

upup

[victorycyz]

select a.*,
b.questionid,
b.answer
from user_self_assessment a join question_answer b
on a.testid=b.testid

[dafu71]

select user_self_assessment.testid,user_self_assessment.userid,user_self_assessment.testdate, question_answer.questionid,question_answer.answer from user_self_assessment inner join question_answer on question_answer.testid=user_self_assessment.testid


where---->on

[leeboyan]

select user_self_assessment.testid,user_self_assessment.userid,user_self_assessment.testdate, question_answer.questionid,question_answer.answer from question_answer left join user_self_assessment on question_answer.testid=user_self_assessment.testid

[leeboyan]

left join ,right join,inner join,full join后跟条件不用where改用on

[leeboyan]

cross join 后不跟条件

[Fibona]

谢了，刚才的问题谢谢各位了，我想再问一下各位，如何给表中增加记录：比如增加的记录如下：
12（testid)，abc(userid),2004-4-02(testdate),1(questionid),a(answer)
括号里的为字段解释，谢谢各位的回答。