average

I need to perform an avg on a column, but I know that most of the values in that column will be zero. Out of all possible rows, only two will probably have positive values. How can I tell mySQL to ignore the zeros and only average the actual values? Assuming that you might want to not totally exclude such rows (perhaps they have values in other columns you want to aggregate) SELECT AVG(NULLIF(field ,0)) from table You could probably control that via the WHERE clause: select avg( field ) from table where field > 0 select avg(your_column) from your_table where your_column != 0 Barvajz You can

I need to generate random numbers with following properties. Min should be 200 Max should be 20000 Average(mean) is 500. Optional: 75th percentile to be 5000 Definitely it is not uniform distribution, nor gaussian. I need to give some left skewness. Java Random probably won't work because it only gives you normal(gaussian) distributions. What you're probably looking for is an f distribution (see below). You can probably use the distlib library here and choose the f distribution . You can use the random method to get your random number. Say X is your target variable, lets normalize the range by

I'm trying to create a program that calculates and displays the highest, lowest and average value of items in a listbox (items generated from a txt file). I finally figured out how to load a text file to the listbox. I have been searching for clues for about an hour and all my attempts have brought me to a dead end. my listbox is called readListbox and my Highest, Lowest and Average labels are called highestLabel, lowestLabel and averageLabel respectively. How do I go about creting this program. The numbers are in the decimal format. Any Help will be very much appreciated. private void

i have a table in mySql like in this picture and i want to write a query which result will group by LESSON column, and add new row which is average value of LESSON column and sum CNT column values.... for this query i use this one i use this query but it gives result like in picture 3 and i cant sort by PERC in this case select no, STUD_ID,CLASS,LESSON, AVG(PERC) as PERC,SUM(CNT) as CNT from t_lesson where LESSON='CHEM' group by CLASS union all select no,STUD_ID,CLASS,'AVERAGE' as LESSON, AVG(PERC) as PERC, SUM(CNT) as CNT from t_lesson where LESSON='CHEM' group by LESSON It looks like you're

I am trying to generate a report and the following code does not produce the desired results which gives me 2 lines rather than one. The ScoreTypeID could have values of 22, 52, 3 or 4 . if it is 22 or 52, I need the average and if not I need to show 0. Any idea what may be the problem ? Thanks. CASE WHEN FAS1.ScoreTypeID = 22 THEN avg(fas1.totalscore) WHEN FAS1.ScoreTypeID = 52 THEN avg(fas1.totalscore) ELSE 0 END AS 'Total Score', I think in your full query, you are missing the GROUP BY clause, eg SELECT ... FROM .... WHERE .. GROUP BY FAS1.ScoreTypeID I think this is what you want: coalesce