使用if条件where子句的M​​ySQL查询

Question

I have table ORDERS with id, appId, status, orderId.

status can - OK, ONHOLD, DONE, REJECT etc

 For this use case i want to filter with status OK and ONHOLD and order if status is "OK" - I want to get allow all orderIds if status is "ONHOLD" - only get ids with whiteList orders. Here the statusList has 2 Strings and whiteListOrders dynamically generated list 

 public List<Long> getIds(
   @Bind("appId") String appId,
   @BindIn("statusList") List<String> statusList,
   @BindIn("whiteListOrders") List<String> whiteListOrders);

How to achieve this in mysql query

Answer 1

Below would be the generic query -

SELECT <req cols> 
FROM   mytable1 
WHERE  status='OK' 
UNION 
SELECT <req cols> 
FROM   mytable 
WHERE  status='ONHOLD' 
AND    id IN 
       ( 
              SELECT orderids 
              FROM   <whitelistorders>)

If you can provide the table and column details, you can do it with join as well.

Hope this helps.

Answer 2

You could union the queries. This will give you the data you want.

(SELECT ids FROM ORDERS WHERE status='OK' AND ids IN (@whiteListIds))
UNION  
(SELECT ids FROM ORDERS WHERE status='ONHOLD' AND ids IN (@whiteListIds))

As mentioned, this would be possible without the UNION :

#set @whitelist = your whitelist IDS; /* Not sure how you have this setup */
SELECT 
  * 
FROM 
  user 
WHERE 
  status='OK' 
  OR (
    status='ONHOLD' 
    AND id IN (@whitelist)
  )

Hope this helps,

Answer 3

Neither of the supplied answers is optimal, as they both use a UNION. There is no reason whatsoever to do this, you can easily add whatever multiple clauses you need by combining clauses inside your WHERE clause using a combination of AND, OR and parenthesis.

I'd also consider using and exists(subquery) rather than using in (subquery)