sql语句

最新推荐文章于 2025-07-24 17:33:23 发布

原创最新推荐文章于 2025-07-24 17:33:23 发布 · 333 阅读

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本文详细解析了SQL查询语句的正确用法，包括使用自定义函数提高查询效率的方法，并对比了错误的查询方式，强调了正确语法的重要性。同时，介绍了如何通过自定义函数f_get_dicmc获取字典项描述，优化查询过程。

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正确:select t.*, f_get_dicmc('RYLB_SJBD',t.rylx ) as rylx
from t_tjfx_syrk_sjbdb t where t.sjly='1' and t.batchno='33238ED6-0E3D-4275-9B5B-33F46FD792AA' order by t.xh;

create or replace function f_get_dicmc(v_zdlb varchar2,v_dm varchar2)
return varchar2
as
v_mc varchar2(250);
begin
select MC into v_mc from t_common_dictionary where zdlb=v_zdlb and dm=v_dm;
return v_mc;
end;

错误:select XH as xh,SFZH as sfzh,XM as xm,XB as xb,MZ as mz,
       (select mc from t_common_dictionary where zdlb ='RYLB_SJBD'
       #if($rylx && !$rylx.equals(""))
               and dm = #[rylx]
       #end ) as rylx,
       HJDQH as hjdqh,HJDXZ as hjdxz,
       DJDWDM as djdwdm,DJDWMC as djdwmc,
       DJRXM as djrxm,DJSJ as djsj,SJBDSJ as sjbdsj
       from t_tjfx_syrk_sjbdb where 1=1
       #if($batchno && !$batchno.equals(""))
               and batchno = #[batchno]
       #end
       #if($sjly && !$sjly.equals(""))
               and sjly = #[sjly]
       #end
       order by xh

insert into t_common_dictionary values('11800452','RYLB_SJBD','人员类别_数据比对','1','常住人口','','','1',null);
insert into t_common_dictionary values('11800453','RYLB_SJBD','人员类别_数据比对','2','流动人口','','','1',null);
insert into t_common_dictionary values('11800454','RYLB_SJBD','人员类别_数据比对','5','寄住人口','','','1',null);
insert into t_common_dictionary values('11800455','RYLB_SJBD','人员类别_数据比对','6','从业人员','','','1',null);
insert into t_common_dictionary values('11800456','RYLB_SJBD','人员类别_数据比对','7','就学人员','','','1',null);