I have a table power with a datetimetz field called sample_time and a column called amp_hours.
The amp_hours field gains a record about every two minute and is reset every night at midnight.
I would like to see sample_time and amp_hours for the last record of every day.
I'm very new to SQL so I may be overlooking an obvious answer.
I saw this post on how to select the last record of a group but I'm not familiar enough with SQL to get it to work for datetimes:
I thought to use lead() or lag() to compare the date of a record with the next record but I'm using postgresql 8.3 and I think windowing was introduced in 8.4.