Using MS Access/Access "Count" function
I have about 1300 length measurements of fish (taken in millimeters) as part of a data project and entered into Access. One of the eventual goals is to create a bar graph (using Excel) of the number of fish in each 2 cm group. Using Access's Integer function I've taken the length data and set up the appropriate 1 cm and 2 cm group for each entry.
450 mm = 45 cm gp (1 cm) or 44-46 cm gp (2 cm gp)
The Access query columns have a data ID #, fish weight (grams), fish length (mm), fish 1 cm gp, fish 2 cm gp. Typical entries are:
100, 2520, 450, 45, 44
101, 2620, 475, 47, 46
102, 3110, 522, 52, 52 etc.
Now I want to count the number of fish in each 2 cm gp so that my data looks like:
34cm: 41, etc.
The data low end would be 200 mm (20 cm gp) and go to about 660 mm (66 cm gp)
Is there a single command or equation that will provide a count for each of the categories? I guess I don't understand the COUNT function options very well, because so far my only solution has been to make a report, sorting by each group and then using COUNT for that group. This would mean manually reentering each group data into the Excel spreadsheet -- it would almost be easier to simply make a manual count from the original query, except that additions or changes would be awkward.
This should be very easy with a Group By query. In Query Design mode, First add your 2 cm group field to the grid, then your DataID field. Press the Sigma icon on the ribbon to turn the query into a Group By. This adds a Group By row to he grid. Set the first (group) column to Group By and the second to Count. Run the query and you will get a count for each group.
Hope this helps,