How should this table be related? ? ?

clinnery

A simpler
Add a record (id, drug name, price) to a (0, no item, 0)
b Add a record as above (id, treatment item, price) (0, no item, 0)
c table contains id_1 (set foreign key association a.id, defaut 0)
           id_2 (Set the foreign key association b.id, defaut 0)

Use c as the main table and as the data window;

fancyzl

The cost classification must be included in the two tables, then the two result sets can be connected!

select c. time, c. medical treatment number, a.ypnam from a, c where a.ypid=c. expense classification
union
select c. time, c. medical treatment number, b.zlname from b, c where b.ypid=c. expense classification
In this way, you don't need to care if there is any.

luckythename

I don't know, Bangding

hxfhxfhxf

select a.ypname,b.zlname,c.* from a,b,c where a.ypid(+)=c.ypid and b.zlid(+)=c.zlid

chiron

The premise is that ypid and zlid cannot be repeated, and the char type can be used, with characters in front of it to distinguish, such as: yp00001, zl00001

select c. time, c. medical treatment number, a.ypname as cost
from c,a
where c. Expense classification = a.ypid
To
union

select c. time, c. medical number, b. zlname as cost
from c,b
where c. Expense classification = b.zlid