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SQL语句PART8

PairWise subquery:
e.g.:
select * from wf_docsort where (ndocsortid,nmoduleinfoid)  in (select ndocsortid, nmoduleinfoid from wf_docsort where instr(cname,'文')>0)
the above sql is the same function as:
select * from wf_docsort where ndocsortid = (select ndocsortid from wf_docsort where instr(cname,'xx')>0) and nmoduleinfoid = (select nmoduleinfoid from wf_docsort where instr(cname,'xx')>0)
A scalar subquery expression is a subquery that: returns exactly one column value from one row. Scalar subqueries can be used in: 1) The condition and expression part of DECODE and CASE 2) All clauses of SELECT except GROUP BY 3) The SET clause and WHERE clause of an UPDATE statement
e.g.:
select * from wf_docsort
results:
1    1    收文            SHOUWEN
2    1    发文            FAWEN
3    1    交办            JIAOBAN
4    2    值班报告     REPORT
5    3    督察督办     SUPERVISAL
6    2    值班快报     DAILYREPORT
7    2    我的事情     NOTIFY
8    4    提案            RESOLUTION
9    4    建议            SUGGESTION
select NDOCSORTID, NMODULEINFOID,CNAME,KEY,(
       case when nmoduleinfoid=(
               select nmoduleinfoid from wf_moduleinfo where nmoduleinfoid=1
        ) then 'JEAN1' else (case when nmoduleinfoid=(select nmoduleinfoid from wf_moduleinfo
 &n


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