Mysql Select从去年开始的事件，但不是今年

Question

I need some direction on a query.

I have an orders table. It has the following columns (among others)

OrderID | OrderDate | CustomerID

I want to find customers who ordered in 2012, but have not ordered in 2013.

(and actually I will eventually want more precision (customers who ordered in March of 2012, but not 2013))

I know I could do two queries -

"SELECT * FROM TABLE WHERE OrderDate BETWEEN 2012-01-01 AND 2012-12-31"
"SELECT * FROM TABLE WHERE OrderDate BETWEEN 2013-01-01 AND 2013-12-31"

and then analyze the results, but it seems like it ought to be possible with pure mysql.

Perhaps a self join? Or a nested SELECT? I'm not very familiar with these and am having a hard time finding a relevant example. Thanks for your help!

Answer 1

No joins required; just filter the orders when grouped on customer:

SELECT   CustomerID
FROM     Orders
GROUP BY CustomerID
HAVING   SUM(OrderDate BETWEEN 2012-03-01 AND 2012-03-31)
 AND NOT SUM(OrderDate BETWEEN 2013-01-01 AND 2013-12-31)

Answer 2

eggyal's answer will work, but it could be very slow since it can't make use of indexes. Assuming you have an index on OrderDate , the following self-JOIN may be better:

SELECT DISTINCT o1.CustomerID
FROM Orders o1
LEFT JOIN Orders o2
ON o1.CustomerID = o2.CustomerID
AND o2.OrderDate BETWEEN '2013-01-01' AND '2013-12-31 23:59:59'
WHERE o1.Orderdate BETWEEN '2012-01-01' AND '2012-12-31 23:59:59'
AND o2.CustomerID IS NULL

Answer 3

My query is more readable. Just subtraction customers of 2013 from customers of 2012.

SELECT `CustomerID` 
FROM `d` 
WHERE 
   `OrderDate` BETWEEN '2012-01-01' AND '2012-12-31 23:59:59' 
   AND `CustomerID` NOT IN
       (SELECT `CustomerID` 
        FROM `d` 
        WHERE 
            `OrderDate` BETWEEN '2013-01-01' AND '2013-12-31 23:59:59' 
        GROUP BY `CustomerID`)
   GROUP BY `CustomerID`

And there is some info about how to rewrite query with subquery to query with join (@Barmar's solution).