How can I count the number of items that where inserted at given time intervall to the DB?

Question

All Columns have a timestamp from that I can get that information. I tried already this but I don't get it to work!!

Answer 1

例如，如果您想按时间戳的小时部分对行的出现次数进行分组，请尝试执行以下操作（MySQL语法）：

select hour(TimeStamp) as interval, count(*) from data group by interval;

Answer 2

Did you try

... WHERE timestamp > 1305211123 AND timestamp < 1305215094

This is for unix timestamp of course, if you have datefield instead it's pretty similar though.