mySQL query question - mysql

Question

I have and ORDERS table from a customer shopping cart. It's the typical customer name, address, etc..list of fields. The twist is that the cart will populate the shipping information into the appropriate fields (shipName, shipAddress, ShipState, etc) when the customer enters shipping information that is different then the billing information. However, when the customer ships to themselves, the cart does not move the shipping information to the proper fields for shipping (i.e., shipName, shipAddress, shipState). It keeps this information in the ordName, ordAddress, ordCity, etc fields and then keeps the shipping related fields empty.
Therefore, these shipping fields are then empty for orders that customers ship to themselves. I used IF commands to move the ordName, ordAddr, etc to alias names when no shipping information is provided so that the shipping information for all order types (whether the customer ships to themselves or to another address) is handled. That part is working fine in my query below.
One issue remains. My shipping program can't use long State name (e.g, Michigan, New York, etc). It needs the state to be the two character abbreviation (e.g, MI, NY). I have a look up table called *STATES that has a mapping between long state name and the two character abbreviation. I am trying to use the ShipState alias to look up the correct two character name for a given state. I tried to do this as a JOIN but keep getting errors. I removed the join I was using and am only showing the code that works correct right now but doesn't do the mapping for state abbreviation. Can someone please help?
SELECT
orders.ordDate AS `Date`,
orders.ordID AS Order_ID,
orders.ordEmail AS Email,
IF(ordShipName = ' ', ordName, ordShipName) AS Name,
IF(ordShipAddress = ' ', ordAddress, ordShipAddress) AS Address_1,
IF(ordShipAddress2 = ' ', ordAddress2, ordShipAddress2) AS Address_2,
IF(ordShipCity = ' ', ordCity, ordShipCity) AS City,
IF(ordShipState = ' ', ordState, ordShipState) AS ShipState,
IF(ordShipZip = ' ', ordZip, ordShipZip) AS Postal,
IF(ordShipCountry = ' ', ordCountry, ordShipCountry) AS Country,
IF(ordShipPhone = ' ', ordPhone, ordShipPhone) AS Phone,
FROM
orders
WHERE
orders.ordID > 21700
HAVING
Country = 'United States of America'

Answer 1

You can't use the column alias ShipState for the join to your lookup table. Instead, repeat your IF construct again:
SELECT
orders.ordDate AS `Date`,
orders.ordID AS Order_ID,
orders.ordEmail AS Email,
IF(ordShipName = ' ', ordName, ordShipName) AS Name,
IF(ordShipAddress = ' ', ordAddress, ordShipAddress) AS Address_1,
IF(ordShipAddress2 = ' ', ordAddress2, ordShipAddress2) AS Address_2,
IF(ordShipCity = ' ', ordCity, ordShipCity) AS City,
IF(ordShipState = ' ', ordState, ordShipState) AS ShipState,
IF(ordShipZip = ' ', ordZip, ordShipZip) AS Postal,
IF(ordShipCountry = ' ', ordCountry, ordShipCountry) AS Country,
IF(ordShipPhone = ' ', ordPhone, ordShipPhone) AS Phone,
STATE.StateAbbreviation
FROM
orders
INNER JOIN STATES
ON IF(orders.ordShipState = ' ', orders.ordState, orders.ordShipState) = STATES.State
WHERE
orders.ordID > 21700
HAVING
Country = 'United States of America'

Answer 2

You should put the code in where you try to join the two tables. You might just have a syntax error that someone could help you with. If you have a table called STATES with columns state and state_abrev, try this:
select ..., .., ..., STATES.state_abrev, ..., ..., from orders, STATES where STATES.state = orders.ordShipState AND ... ... HAVING ...

Answer 3

Since the origin of the data is a small set of transaction it will be very fast, I would have it do a left join to two instances of the states table respectively on their field and have your SELECT based on whichever was not empty... such as
select
...(other fields),
IF(orders.ordShipState = ' ', s1.StateName, s2.StateName ) as StateName
from
Orders
left outer join states s1
on orders.ordstate = s1.state
left outer join states s2
on orders.ordShipState = s2.state
where
orders.ordID > 21700
(etc with rest of query)...
This way, the join will always be having a join based on BOTH POSSIBLE states... So, whichever one exists, based on your preference, get THAT state first, otherwise get the other.