I am new in MySql and help will be much appreciated
I had this assignment which is to get the sum and average of dynamic rows in the table. The table looks like
tbl_grade
id scores
1 10
1 11
1 9
1 10
1 6
2 10
2 9
2 10
I want to show the results like this
id sum average
1 46 9.2
2 29 9.7
Hope anyone can help. Thanks
This is a simple query using GROUP BY clause and the aggregate methods SUM and AVG. For a better understanding about grouping and aggregate methods, please read next: http://www.mysqltutorial.org/mysql-group-by.aspx
SELECT
id,
SUM(scores),
AVG(scores)
FROM
tbl_grade
GROUP BY
id
Related
pnr mnd pris
1 1 600
1 7 900
2 1 600
2 7 600
3 1 40
3 7 40
I have trouble how to sum specific rows on the columns. Looking at the above, the table is called travel and it has 3 columns:
pnr - Personal Number
mnd - Month
Pris - Price
So what I want is to sum total of the price for the a specific month, so in this case, it should be 1240 USD and month 1. For the month 7, it should be 1540 USD.
I have trouble to do the query correct. So far from I have tried is this:
SELECT t.rnr, t.mnd, SUM(t.pris)
FROM travel AS t
WHERE t.mnd = 1
The result I get is 3720 USD which I have no idea how the SQL managed to calculate this for me.
Appreciate if someone could please help me out!
For this you need to drop the pnr column from the output (it is not relevant and will cause your data to split) and add a GROUP BY:
SELECT t.mnd, SUM(t.pris)
FROM travel AS t
WHERE t.mnd = 1
GROUP BY t.mnd
Live demo: https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=b34ec2bb9c077c2d74ffc66748c5c142
(The use of an aggregate function without grouping, as you've got now, is not a standard SQL feature and can often be turned off in MySQL. If turned on, you might not always get the result you expected/intended.)
just group your result with mnd column
SELECT t.mnd, SUM(t.pris)
FROM travel AS t
group by t.mnd
I am using laravel framework. i want to get the count of MySQL count occurrences of id. Here is my problem. My table name is download_histories. Here is my record for demo :-
Table:- download_histories
id alt_image_id
1 25
2 25
3 26
4 27
5 29
6 26
Now look at the table. Now this table having 6 records and alt_image_id 25 coming twice times and alt_image_id 26 coming twice times .and 27 and 29 coming once .
Now i want the result when group of alt_image count is greater then equal to 2. Now i want the count of groupby records can anyone help me. I want the count that is 2
i have done so far :-
DB::table('download_histories')
->select(DB::raw('count(download_histories.user_id) as totaluserdownload'))
->groupby('alt_image_id')
->having('totaluserdownload','>=',2)
->get();
Note : i want the count not get the data . Please help me. Thanks in advance :)
I have 3 table. final,milestone and milestonewp consider that the three tables is foreigned key like milestonewp<--FK--milestone<--FK--Final .Then I have a column for determining the average of the milestonewp for a certain foreign key. Then getting that average to be average again to be displayed to the final table.Here is my visual representation
milestonewp
condition | mile_id
20 1
20 1
30 1
21 2
21 2
31 2
40 3
30 3
50 3
How can I average the average that the chart above will produce?
I'm trying to work on this
select avg(milewp_condition)
from logs_pms_r_milestone_wp
where mile_id=1;
but i dont have any idea how it can produce for the other mile_id
EDIT
The above code will produce something like this
avg(milewp_condition)
0
0
0
so then, i also want to average that 3 rows.
If I understand well this should be what you look for:
SELECT AVG(milewp_condition)
FROM logs_pms_r_milestone_wp
GROUP BY mile_id;
If you want to average all, just do:
SELECT AVG(milewp_condition)
FROM logs_pms_r_milestone_wp;
Regards
At first I would like greet all Users and apologize for my english :).
I'm new user on this forum.
I have a question about MySQL queries.
I have table Items with let say 2 columns for example itemsID and ItemsQty.
itemsID ItemsQty
11 2
12 3
13 3
15 5
16 1
I need select itemsID but duplicated as many times as indicated in column ItemsQty.
itemsID ItemsQty
11 2
11 2
12 3
12 3
12 3
13 3
13 3
13 3
15 5
15 5
15 5
15 5
15 5
16 1
I tried that query:
SELECT items.itemsID, items.itemsQty
FROM base.items
LEFT OUTER JOIN
(
SELECT items.itemsQty AS Qty FROM base.items
) AS Numbers ON items.itemsQty <=Numbers.Qty
ORDER BY items.itemsID;
but it doesn't work correctly.
Thanks in advance for help.
SQL answer - Option 1
You need another table called numbers with the numbers 1 up to the maximum for ItemsQuantity
Table: NUMBERS
1
2
3
4
5
......
max number for ItemsQuantity
Then the following SELECT statement will work
SELECT ItemsID, ItemsQty
FROM originaltable
JOIN numbers
ON originaltable.ItemsQty >= numbers.number
ORDER BY ItemsID, number
See this fiddle -> you should always set-up a fiddle like this when you can - it makes everyone's life easier!!!
code answer - option 2
MySQL probably won't do what you want 'cleanly' without a second table (although some clever person might know how)
What is wrong with doing it with script?
Just run a SELECT itemsID, ItemsQty FROM table
Then when looping through the result just do (pseudo code as no language specified)
newArray = array(); // new array
While Rows Returned from database{ //loop all rows returned
loop number of times in column 'ItemsQty'{
newArray -> add 'ItemsID'
}
}//end of while loop
This will give you a new array
0 => 11
1 => 11
2 => 12
3 => 12
4 => 12
5 => 13
etc.
Select DISTINCT items.itemsID, items.itemsQty From base.items left outer join (select items.itemsQty as Qty from base.items) As Numbers On items.itemsQty <=Numbers.Qty
order by items.itemsID;
Use DISTINCT to remove duplicates. Read more here - http://dev.mysql.com/doc/refman/5.0/en/select.html
It seems like I understood what you asked differently than everyone else so I hope I answer you question. What I would basically do is -
create a new table for those changes.
Create a mysql procedure which given a line in the original table add new lines to the new table - http://dev.mysql.com/doc/refman/5.6/en/loop.html
Run this procedure for each line in the original table.
try this to get distinct values from both columns
SELECT DISTINCT itemsID FROM items
UNION
SELECT DISTINCT itemsQty FROM items
studentname I II
Vivek Johari 30 20
Chandra Singh 30 20
Avinash Dubey 30 25
Pankaj Kumar 33 29
I have a table named student with details as above. I want to find the average of column I and II and display it on a new column using pivot. Please help me to solve this using pivot..
May I use any sub query to solve this using pivot...
your questions is not specific enough.
Do you want the total average of both columns? just do
select avg (I), avg(II)
from your_table
if you want just one value, you can do:
select (avg (I) + avg(II))/2
from your_table