Question

UPDATE SELECT操作 在mybatis里为什么放在<select>标签里？

mybatis的XML文件里SQL如下： 为什么放在select标签里，而且无返回值？求SQL大神解释。

<select id="setFaltCountByResourceId">
UPDATE ts_testfalttree INNER JOIN (
SELECT sectionResourceId, leveCode, count(exerciseId) faultNum FROM (
SELECT ts_testfaltdetail.exerciseId, sr.sectionResourceId,sr.leveCode
FROM (select * from ts_testfaltdetail where studentId = #{studentid,jdbcType=BIGINT} ) ts_testfaltdetail right join (
SELECT sr2.sectionResourceId,sr2.levecode
FROM ts_studyresource sr1,ts_studyresource sr2
WHERE sr1.sectionResourceId = #{sectionresourceid,jdbcType=BIGINT}
AND LEFT(sr1.leveCode ,5) = LEFT(sr2.leveCode,5)) sr
ON sr.sectionResourceId = ts_testfaltdetail.sectionResourceId
) a
group by sectionResourceId ) b
ON ts_testfalttree.sectionResourceId = b.sectionResourceId
SET ts_testfalttree.faltCount = b.faultNum
</select>

Answer 1

你的SQL 主体在做Update操作, 所以最外面的标签需要从<select></select>改为<update></update>就可以正常返回了.