Join get wrong information on query - sql

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?

Answer 2

Following is a testscript and the output from your statement.
Perhaps it's easier to work from here and you tell us what is wrong with this output.
The testscript can be adjusted and executed here
Output
ID State StateName
----------- ----------- ---------
1 1 Attended
11 1 Attended
12 1 Attended
15 2 Declined
Test Script
;WITH Sales AS (
SELECT * FROM (VALUES
(1, 1)
, (2, 1)
, (3, 6)
) AS Sales (ID, StateID)
)
, Orders AS (
SELECT * FROM (VALUES
(11, 2)
, (12, 2)
, (15, 3)
) AS Orders (ID, StateID)
)
, StatesEquivalence AS (
SELECT * FROM (VALUES
(1, 1, 2, 'Attended')
, (2, 2, 3, 'Declined')
) AS StatesEquivalence (ID, SalesState, OrdersState, StateName)
)
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

Answer 3

I didn't understand what you need exactly, but maybe is this?
select *
from StatesEquivalence EQ
full join Sales S on EQ.SalesState = S.StateId
full join Orders O on EQ.OrdersState = O.StateId
This is a starting point maybe...