Question

I’m having some problems with join query. What I want is select rows of two tables that have some similar states, others no. And I have a state-equivalence view

Table Sales:
ID  .....   StateID
1           1
2           1
3           6

Table Orders
ID  .....   StateID
11          2
12          2
15          3

Table StatesEquivalence
ID  SalesState   OrdersState    StateName
1   1            2              Attended
2   2            3              Declined

I’ve made a union of both tables(Sales and Orders) and I want a column with the EquivalentStateID and the StateName by doing something like this:

SELECT sales.ID as ID,equivalence.ID as State,equivalence.StateName
FROM Sales
INNER JOIN StatesEquivalence as equivalence
ON sales.StateID = equivalence.SalesState
WHERE sales.ID = 1
UNION
SELECT orders.ID as ID,equivalence.ID as State,equivalence.StateName
FROM Orders as orders
INNER JOIN StatesEquivalence as equivalence
ON orders.StateID = equivalence.OrdersState

Somehow I am obtaining wrong information on the equivalentID

ID      State        StateName
1       2            Attended
2       2            Attended
11      2            Attended
...

I don’t know what happend.. because the statename is correct, but the StateID is showing wrong information

The table might show this:

ID      State        StateName
1       1            Attended
2       1            Attended
11      1            Attended
...

Answer 1

I don’t think you are showing us the real problem code. I did the following:

begin transaction

create table sales (id int, stateid int)
create table orders (id int, stateid int)
create table statesequivalence (id int, salesstate int, ordersstate int, statename varchar(20))

insert into sales values (1, 1)
insert into sales values (2, 1)
insert into sales values (3, 6)

insert into orders values (11, 2)
insert into orders values (12, 2)
insert into orders values (15, 3)

insert into statesequivalence values (1, 1, 2, 'Attended')
insert into statesequivalence values (2, 2, 3, 'Declined')

SELECT sales.ID as ID,equivalence.ID as State,equivalence.statename
FROM Sales
INNER JOIN statesequivalence as equivalence
ON sales.StateID = equivalence.SalesState
WHERE sales.ID = 1
UNION
SELECT orders.ID as ID,equivalence.ID as State,equivalence.StateName
FROM Orders as orders
INNER JOIN statesequivalence as equivalence
ON orders.StateID = equivalence.OrdersState

rollback

Result:

ID          State       statename
----------- ----------- --------------------
1           1           Attended
11          1           Attended
12          1           Attended
15          2           Declined

So, it works. Can you try the above code?