Assume a service is billed in the following manner:
The first 60 seconds is charged at $1.00
Subsequent charges are billed at $0.25 per 10 second
The following are example computations:
32 seconds = $1.00
59 seconds = $1.00
60 seconds = $1.00
61 seconds = $1.25
69 seconds = $1.25
70 seconds = $1.25
71 seconds = $1.50
Is it possible to do this kind of computation in MySQL alone?
EDIT 1:
Does something like this work:
SELECT `call_length`,
( 1.00 + ( Round(( `call_length` - 30 ) / 10) * .25 ) ) AS `cost`
FROM `service`
SqlFiddleDemo
CREATE TABLE sec(val INT);
INSERT INTO sec
VALUES (32), (59), (60), (61), (69), (70), (71);
SELECT
val,
1.0 + CASE
WHEN val <= 60.0 THEN 0
WHEN val MOD 10 = 0 THEN 0.25 *((val - 60) DIV 10)
ELSE 0.25 * (((val - 60) DIV 10) + 1)
END AS charge
FROM sec;
EDIT:
Without CASE:
SqlFiddleDemo2
SELECT
call_length,
1.0 + IF( call_length <= 60, 0, 0.25 * CEIL((call_length - 60)/10)) AS cost
FROM service;
This is not much of a MySQL problem, unless the setting in which you need to perform the calculation is somehow difficult(?).
UPDATE ... SET cost_cents = 100 + CEIL(GREATEST(0, duration - 60)/10) * 25;
As a SELECT to match your edit,
SELECT `call_length`,
100 + CEIL(GREATEST(0, `call_length` - 60)/10) * 25 AS `cost`
FROM `service`
Note that this returns cents. For dollars, divide the result by 100...
SELECT `call_length`,
(100 + CEIL(GREATEST(0, `call_length` - 60)/10) * 25) / 100 AS `cost`
FROM `service`
Related
I have the following table:
id (integer, primary key)
amount_low (integer)
amount_high (integer)
fixedprice (decimal 4,2 Null)
percentadjust (decimal 4,2 Null)
itemname (varchar 50)
A record will have a value in either the "fixedprice" or "percentadjust" field, but not both. One will be NULL, and the other will have a value.
I need to get records based on a single input amount, "X":
If the "fixedprice" field has a value, I need to get the record if X is >= (fixedprice * amount_low) AND X is <= (fixedprice * amount_high).
If the "percentadjust" field has a value, I need to get the record if X is >= ((((percentadjust / 100) + 1) * 3.5) * amount_low) AND X is <= ((((percentadjust / 100) + 1) * 3.5) * amount_high).
The "3.5" is a value that changes on occasion and I'm not too concerned about that part.
What is a good way to do this in MySQL?
Sample data: (also see http://sqlfiddle.com/#!9/922a0 )
id amount_low amount_high fixedprice percentadjust itemname
-----------------------------------------------------------------
1 20 25 2.25 NULL A
2 50 75 2.38 NULL B
3 23 32 NULL 9.75 C
4 14 22 NULL 9.12 D
5 96 112 2.58 NULL E
Assuming your X was entered as 111 it would be
select * from tblItems
where (fixedprice is not null and 111>=(fixedprice * amount_low) and 111 <= (fixedprice * amount_high) )
OR (percentadjust is not null and 111>=((((percentadjust / 100) + 1) * 3.5) * amount_low) AND 111<=((((percentadjust / 100) + 1) * 3.5) * amount_high))
Note you can always write it as where xyz between A and B to simplify somethings slightly.
Remember that a lot of time can be wasted debugging logic operators when AND and OR are used and safe wrappers with parentheses are not used. So, if you intermingle AND with OR, wrap things well.
I am trying to generate a random value between 0.01 - 0.50 to enter into mysql. I have 2.7 million rows that I need to execute this on.
Here is my script:
UPDATE FBAInventory SET buyBox = ROUND( 0.01 + RAND( ) * 8,2 );
It is generating values such as 4.20, 3.89 etc. I only want it to span from 0.01 - 0.50 and not to exceed this.
Does anyone know how to do this?
Thanks!
How about...
round(rand() * 0.49 + 0.01, 2);
You can use the floor function to generate a range of random numbers.
FLOOR(RAND() * (<max> - <min> + 1)) + <min>
where the max and min are inclusive. So in your case you would want
FLOOR(RAND() * 1.49 ) + 0.01
I have a MySQL table which looks like this:
id load_transit load_standby hours_transit hours_standby
1 40 20 8 4
2 30 15 10 10
3 50 10 3 9
I need to do the following calculations:
(intermediate calculations)
hours_transit_total = 8+10+3 = 21
hours_standby_total = 4+10+9 = 23
(desired result)
load_transit_weighted_mean = 40*(8/21) + 30*(10/21) + 50*(3/21) = 36.667
load_standby_weighted_mean = 20*(4/23) + 15*(10/23) + 10*(9/23) = 13.913
Is it possible to do this in a single query? What would the best design be?
Note that
40*(8/21) + 30*(10/21) + 50*(3/21) =
(40*8)/21 + (30*10)/21 + (50*3)/21 =
(40*8 + 30*10 + 50*3)/21
and
20*(4/23) + 15*(10/23) + 10*(9/23) =
(20*4)/23 + (15*10)/23 + (10*9)/23 =
(20*4 + 15*10 + 10*9)/23
Which allows you to get the results you want using
SELECT sum(hours_transit * load_transit) / sum(hours_transit),
sum(hours_standby * load_standby) / sum(hours_standby)
FROM your_table
I just had this same question and built this little query I think makes it clear how to find the weighted average in a single query:
select sum(balance), sum(rate * balance / 5200) as weighted_rate, -- what I want
-- what you cannot do: sum(rate * balance / sum(balance))
sum(balance * rate) / sum(balance) as weighted_rate_legit -- ah thank you transitive math properties
from (
select '4600' as balance, '2.05' as rate from dual
union all
select '600' as balance, '2.30' as rate from dual
) an_alias;
Can I ask for help on a SQL Statement please, I have to do the calculation inline and cannot declare variables for it
Calculation:
-91000000 / 2700000 = -33.7037037037
I need the remainder (7037037037 - but only up to 6 characters ) to be multiplied by 15000
703703 / 15000 = Final Answer of 49.913533
I thought I could do this:
select cast(ParseName(abs(cast(-91000000 as decimal)/ 2700000 ) %1,1) as numeric(8,8)) / 15000
WITH cte AS
(
SELECT -91000000 AS x, 2700000 AS y
)
SELECT ABS(ROUND((CAST(x AS decimal) / CAST(y AS decimal)) - (x/y), 6)) * 1000000 / 15000 FROM CTE
I have a field on my table which represents seconds, I want to convert to minutes
Select (100/60) as Minute from MyTable
-> 1.66
How can I get 1 minute and 40 seconds 00:01:40 and then round to 00:02:00 and if 00:01:23 round to 00:01:30
Using Mysql.
There are two ways of rounding, using integer arithmetic and avoiding floating points, a value to the nearest thirty seconds...
((seconds + 15) DIV 30) * 30
(seconds + 15) - (seconds + 15) % 30
The latter is longer, but in terms of cpu time should be faster.
You can then use SEC_TO_TIME(seconds) to get the format hh:mm:ss, and take the right 5 characters if you really need hh:mm.
If you wanted to avoid SEC_TO_TIME(seconds), you can build up the string yourself.
minutes = total_seconds DIV 60
seconds = total_seconds % 60
final string = LPAD(minutes, 2, '0') | ':' | LPAD(seconds, 2, '0')
i am not sure about how to round it but you can convert seconds into time i.e hh:mm:ss format using SEC_TO_TIME(totaltime)
Desired result :
A = 30
B = 60
C = 90
D = 120
select
(25 + 15)-(25 + 15) % 30 as A,
(32 + 15)-(32 + 15) % 30 as B,
(90 + 15)-(90 + 15) % 30 as C,
(100 + 15)-(100 + 15) % 30 as D
Result :
A = 30
B = 30
C = 90
D = 90
I try with this:
select
30* ceil(30/30) as A,
30* ceil(32/30) as B,
30* ceil(90/30) as C,
30* ceil(100/30) as D
Result :
A = 30
B = 60
C = 90
D = 120
Thank you for your help !
You can simply write your own function http://dev.mysql.com/doc/refman/5.0/en/create-procedure.html
But I'd rather do that in a programing language (PHP, Python, C), not on the database side.