Join vs. sub-query I am an old-school MySQL user and have always preferred JOIN over sub-query. But nowadays everyone uses sub-query and I hate it, I don't know why. I lack the theoretical knowledge to judge for myself if there is any difference. Is a sub-query as good as a JOIN and therefore there is nothing to worry about? Answer: Taken from the manual (14.2.10.11 Rewriting Subqueries as Joins):       A LEFT [OUTER] JOIN can be faster than an equivalent subquery because the server      

Retrieving the last record in each group There is a table messages that contains data as shown below: Id Name Other_Columns ------------------------- 1 A A_data_1 2 A A_data_2 3 A A_data_3 4 B B_data_1 5 B B_data_2 6 C C_data_1 If I run a query select * from messages group by name, I will get the result as: 1 A A_data_1 4 B B_data_1 6 C C_data_1 What query will return the following result? 3 A A_data_3 5 B B_data_2 6 C C_data_1 That is, the