问题
Suppose you have a table in SQL:
Prices
------
13.99
14.00
52.00
52.00
52.00
13.99
How would you count the amount of times a DIFFERENT field has been entered in? Therefore an example of such a count would output:
13.99 - 2 times.
14.00 - 1 times.
52.00 - 3 times.
OR perhaps:
3 (i.e. 13.99, 14.00, 52.00)
Can anyone advise? Cheers.
回答1:
How about:
SELECT Prices, COUNT(*) FROM TheTable GROUP BY Prices
Can't say I've tried it on MySql, but I'd expect it to work...
来源：https://stackoverflow.com/questions/1605886/counting-instances-of-unique-value-in-field