oracle 语句 查询优化select count(*),sum(bal) from rpt_xd where substr(beg_date,5,2)= substr('20130131',5,2) and substr(beg_date,1,4)=substr('20130131',1,4) and term_mon3 and term_mon6 and term_mon12能不能帮我弄成一句话啊 这样分着

oracle查询语句 select a||','||b||','||c from table where a in('m','n') oracle 中见到一个查询语句,select /*+ index(t1) */ from t1 .,其中/*+ oracle 语句 查询优化select count(*),sum(bal) from rpt_xd where substr(beg_date,5,2)= substr('20130131',5,2) and substr(beg_date,1,4)=substr('20130131',1,4) and term_mon3 and term_mon6 and term_mon12能不能帮我弄成一句话啊 这样分着 实现关系代数表达式的优化算法 .输入：关系代数表达式或SELECT查询语句 输出：优化后的关系代数表达式 oracle查询一个表,select * from a 所有的字段都是浮点型,想保留3个小数,怎么写语句?类似select round(*,3) from a,还是怎么写? oracle 多表查询速度太慢.求帮我优化一下select jbjxxid,anjianmingcheng,JBJXXSLBH,SARJBXXID,SARMC,JBDWMC from tb_jbjxx,tb_ajjbxx,tb_sarjbxx,tb_xyr,tb_chengbaoxinxiwhere tb_jbjxx.JBJXXID=tb_ajjbxx.JBJXXSLBH or tb_ajjbxx.QTRYXXSLBH=tb_sarjb oracle 优化查询效率select t.dwmc,t.zgjl,t.zbjl,t.zqjl,t.xljl,t.skjl,t.bgjl, t.bqjl,t.bgjl2,t.pxjl,t.ccjl, (zbjl+zqjl+xljl+skjl+bgjl+bqjl+bgjl2+pxjl+ccjl) as hz from (select code_mean as dwmc, (select count(*) from tableoneb, tabletwo a w oracle 子查询:select *,(select account from t_ps_member m where m.mid = po.mid) account from t_ps oracle sql语句获取前两条数据select id,seq from hzds_admin where seq 一条平常用的查询语句 怎么优化. Oracle查询条件的检索顺序 select * from tabel_1 t where t.aa like '%aaa%' and t.bb like '%ccc%'请问：就上述语句,Oracle的机制会怎样查找符合条件的结果1：先找到符合 bb like ccc 的结果,再从该结果中找 aa lik oracle 语句优化问题select nvl(sum(a.sl),0),nvl(sum(a.je),0)from tablea aleft join tableb bon a.zd = b.zdwhere a.zd2 in ('181','180','179','178','177','176','175')and nvl(b.zd3,'xx') = 'xx'类似这样的语句 zd、zd2是字段 都有索引在p oracle 查询优化select count(*),sum(bal) from rpt_xd where substr(beg_date,5,2)= substr('20130131',5,2) and substr(beg_date,1,4)=substr('20130131',1,4) and term_mon3 and term_mon6 and term_mon12各位能帮我把它变成一句话吗 只有 SQL的SELECT语句有哪几部分构成?,作用分别是什么?,如何利用它们表达查询要求? 帮我写个联合查询语句写一条select语句,把title,area,year联合查询出来select year,area,title from film,filmtitle如果用这个查询语句,如何解决重复问题? 求单表查询的hql语句怎么写sqL如下：select * from aaa20 where aaae2001 = '11111111';求hql语句写法 帮我看看这个oracle语句,select groupid,parentid,groupname,isleaf,description,sharerankid,statusid,corporationid,staffid,isactual,groupcount,level FROM (SELECT a.*,b.groupcount FROM teabgroup a,(SELECT groupid,count(*) groupcount FROM teabmembe 大侠这个查询语句的意思?大侠这个查询语句的意思是什么?sql=select DISTINCT 日期 from +tablename+ where 日期>=' +df +' and 日期