Oracle 表A上有个字段aa,aa有4种值(1,2,3,4),字段aa如果等于1就查询B1...答:select t.* from(select a.aa,xx,yy,zz,'b1' table_name from a,b1 where a.aa=b1.id and b1.n=23union allselect a.aa,xx,yy,zz,'b2' table_name from a,b2 where a.aa=b2.id and b2.n=18union allselect a.aa,xx,yy,zz,'b3' table_name from a,b3 where...
oracle 一张表有两个字段,a和b,字段值a=b和b=a,算作一条,怎么操作?答:select data_info,business_a,business_b from (select a.data_info,a.business_a,a.business_b,row_number() over(order by a.business_a) rk -- 按某一字段升序(降序也行)排列 from 表名 a, -- 表自身做关联 表名 b where a.business_a = b.business_b -- 两字段互相等 ...