Question

I have a table called myTable which is like this:

id, myDate, name, group  
1, 2012-04-09, john, subGroup-A  
2, 2012-04-10, marc, subGroup-B

I would like to retrieve the record with the maxDate and the name that goes with it, for the subGroup that starts with ‘subGroup’. So I am doing the following query:

SELECT max(myDate) AS maxDate, name FROM myTable WHERE group LIKE "subGroup%";

I would expect this query to return me this:

maxDate, name  
2012-04-10, marc

But instead it is returning me this:

maxDate, name  
2012-04-10, john

So basically the maxDate is taken correctly, but the name is not the one corresponding to that date. I really do not get it. Hope someone can help me understand. Thank you in advance for your replies. Cheers. Marc

Answer 1

Your query is:

 SELECT max(myDate) AS maxDate, name FROM myTable WHERE group LIKE "subGroup%";

I think you need the following:

SELECT MAX(myDate) AS maxDate, name 
FROM  myTable 
GROUP BY NAME 
HAVING group LIKE "subGroup%"

or

SELECT myDate AS maxDate, name 
FROM myTable 
WHERE group LIKE "subGroup%" AND myDate = (SELECT MAX(myDate) FROM myTable)