Hello, all--I have a large collection of water quality data collected every 30 minutes from 1999 to 2006. I have attached a truncated version of one of my tables so you can see what I am working with.
I need to conduct some calculations on these "DO_pct" and "DO_mgl" data at overlapping...
I am so happy right now I could burst. I have learned so much from you and will be forever grateful...I am in Oregon, and probably it is ridiculous to consider sending cookies to the other side of the globe, but maybe I'll make them for you and give them to someone else, hmmm? Many, many...
With a little tweaking, I have what I need with one "little" exception that I swear will solve all this once and for all!! Ha!
I'm attaching "version 2" of the "Scaled down SWMP" database that includes your queries; I modified one of yours and have added four versions of it (one each for H, L...
Okay...here's my scaled-down database, with one month of data in the 30-minute table, and the times and heights for H, L, LL and HH for the same time period in the 6-minute table (from whose full glory I will spare you). I verified that the phenomenon I mentioned above (a "midnight straddle" of...
Weeeelllllll....I'm baaaaack...
Fortunately I've noticed that there's a problem, and even more fortunate is that you guys might be able to help me again (or so I'm hoping). My final query of the series asks the 30 minute table for the max and min of water levels occurring during specific time...
Yes, Brian...that is exactly what I'm after. I have so far gotten very, very close using John's advice, but it has required a rather cluttery pile of queries. I will probably be able to find what I'm after on my present track, but if you have an all-in-one query design I would be most pleased...
Hello, John--Yes, I am familiar with the "max/min" feature, and have used it to acquire the daily HH and LL (the daily max and min) values in my 30-minute table; the values I seek are the daily secondary highs and lows that are not simply the values on one side or the other of the HH or LL...
Hello, Smart Folks--I have a database consisting of water levels (tidal heights) collected every 30 minutes for a year at one station, every six minutes at another. There are two high tides on most days, and two low tides on most days; one high tide is higher than the other ("HH" for "higher...