In Oracle, I want to write a SELECT query that will find 1.75 percentage off an existing column that has whole numbers in each row and round it to the nearest dollar.
I have somewhat of my query down, but can't figure out how to write the formula to perform the percentage off calculation.
SELECT R.LAST_NAME, O.RENT_FEE, ROUND(RENT_FEE,0) AS DISCOUNT
FROM ROOM_UNIT R, OWNER O
WHERE R.OWNER_NUM = O.OWNER_NUM
From math lessons we know that discounting by x percent is equivalent to multiplying by
(1-x/100)
In your case, discounting by 1.75% means multiplying by, (1 - 0.0175) or 0.9825:
SELECT R.LAST_NAME, O.RENT_FEE, ROUND((1 - 0.0175) * RENT_FEE,0) AS DISCOUNT
FROM ROOM_UNIT R, OWNER O -- ^^^^^^^^^^^^
WHERE R.OWNER_NUM = O.OWNER_NUM
Related
I want to calculate percentage of two columns after sum of the existing record related to specific user.
SELECT SUM(total_marks) AS TotalMarks,
SUM(obt_marks) AS ObtainedMarks,
TotalMarks/ObtainedMarks*100 As Percentage
FROM ExamResult WHERE (student_id = '5')
You cannot use column aliases once they are defined. Instead, repeat the expressions:
SELECT SUM(total_marks) AS TotalMarks,
SUM(obt_marks) AS ObtainedMarks,
SUM(total_marks) * 100.0 / SUM(obt_marks) As Percentage
FROM ExamResult
WHERE student_id = 5;
Notes:
I removed the single quotes around 5. Presumably, the id column is a number, not a string. (If it is a string, keep the quotes).
I multiplied by 100 before the division. I find this logic easier to follow (you don't have to think about which is processed first, the multiplication or division).
I added a decimal point to the 100. This prevents integer division, if the columns happen to be integers.
I have two tables, A & B.
Table A has a column called Nominal which is a float.
Table B has a column called Units which is also a float.
I have a simple select query that highlights any differences between Nominals in table A & Units in table B.
select coalesce(A.Id, B.Id) Id, A.Nominal, B.Units, isnull(A.Nominal, 0) - isnull(B.Units, 0) Diff
from tblA A full outer join tblB B
on tblA.Id = tblB.Id
where isnull(A.Nominal, 0) - isnull(B.Units, 0) <> 0
this query works. However this morning I have a slight problem.
The query is showing on line as having a difference,
Id Nominal Units Diff
FJLK 100000 100000 1.4515E-11
So obviously one or both of the figures are not 100,000 exactly. However when I run a select query on both tables (individually) on this id both of them return 100,000 I can't see which one has decimal places, why is this? Is this some sort of default display in SQL Server?
In the excel you will find this kind of behavior.
It's a standard way to represent a low numbers. The number 1.4515E-11 you got is same 1.4515 * 10^(-11)
I'm working on some SQL code as part of my University work. The data is factitious just to be clear. I'm trying to count the occurances of 1 & 0 in the SQL table Fact_Stream, this is stored in the Free_Stream column/attribute as a Boolean/bit value.
As calculations cant be made on bit values (at least in the way I'm trying) I've converted the value to an integer -- Just to be clear on that. The table contains information on a streaming companies streams, a 1 indicates the stream was free of charge, a 0 indicates the stream was paid for. My code:
SELECT Fact_Stream.Free_Stream, ((CAST(Free_Stream AS INT)) / COUNT(*) * 100) As 'Percentage of Streams'
FROM Fact_Stream
GROUP BY Free_Stream
The result/output is nearly where I want it to be, but it doesn't display the percentage correctly.
Output:
Using MS SQL Management Studio | MS SQL Server 2012 (I believe)
The percentage should be based on all rows, so you need to divide the count per 1/0 by a count of all rows. The easiest way to get this is utilizing a Windowed Aggregate Function:
SELECT Fact_Stream.Free_Stream,
100.0 * COUNT(*) -- count per bit
/ SUM(COUNT(*)) OVER () -- sum of those counts = count of all rows
As "Percentage of Streams"
FROM Fact_Stream
GROUP BY Free_Stream
You have INTs as a devisor and devidened(not sure I am correct with namings). So the result is also INT. Just cast one of those to decimal(notice how did I change to 100.0). Also you should debide count of elements in group to total count of rows in the table:
select Free_Stream,
(count(*) / (select count(*) from Free_Stream)) * 100.0 as 'Percentage of Streams'
from Fact_Stream
group by Free_Stream
Your equation is dividing the identifier (1 or 0) by the number of streams for each one, instead of dividing the count of free or paid by the total count. One way to do this is to get the total count first, then use it in your query:
declare #totalcount real;
select #totalcount = count(*) from Fact_Stream;
SELECT Fact_Stream.Free_Stream,
(Cast(Count(*) as real) / #totalcount)*100 AS 'Percentage of Streams'
FROM Fact_Stream
group by Fact_Stream.Free_Stream
I found it hard to describe what I wanted to do in the title, but I will be more specific here.
I have a reasonably long query:
SELECT
/*Amount earned with validation to remove outlying figures*/
Case When SUM(t2.[ActualSalesValue])>=0.01 OR SUM(t2.[ActualSalesValue])<0 Then SUM(t2.[ActualSalesValue]) ELSE 0 END AS 'Amount',
/*Profit earned (is already calculated then input into db, this just pulls that figure*/
SUM(t2.[Profit]) AS 'Profit',
/*Product Type - pulls the product type so that we can sort by product*/
t1.[ucIIProductType] AS 'Product Type',
/*Profit Percentage - This is to calculate the percentage of profit based on the sales price which uses 2 different columns - Case ensures that there are no wild values appearing in the reports as previously experienced*/
Case When SUM(t2.[ActualSalesValue])>=0.01 OR SUM(t2.[ActualSalesValue])<0 THEN (SUM(t2.[Profit])/SUM(t2.[ActualSalesValue])) ELSE 0 END AS 'Profit Percentage',
/*Percentage of Turnover*/
*SUM(t2.[ActualSalesValue])/(Select SUM(t2.[ActualSalesValue]) OVER() FROM [_bvSTTransactionsFull]) AS 'PoT'
/*The join is connect the product type with the profit and the amount*/
FROM [dbo].[StkItem] AS t1
INNER JOIN [dbo].[_bvSTTransactionsFull] AS t2
/*There attirbutes are the links between the tables*/
ON t1.[StockLink]=t2.[AccountLink]
WHERE t2.[TxDate] BETWEEN '1/Aug/2014' AND '31/Aug/2014' AND ISNUMERIC(t2.[Account]) = 1
Group By t1.[ucIIProductType]
The 'Percentage of Turnover' part I am having trouble with - I am trying to calculate the percentage of the Amount based on the total amount - using the same column. So eg: I want to take the Amount value in row 1, then divide it by the total amount of the entire column and then have that value listed in a new column. But I keep getting errors or I Keep getting 1 (because it wants to divide the value by the same value. CAN anyone please advise me on proper syntax for solving this:
/*Percentage of Turnover*/
*SUM(t2.[ActualSalesValue])/(Select SUM(t2.[ActualSalesValue]) OVER() FROM [_bvSTTransactionsFull]) AS 'PoT'
I think you want one of the following:
SUM(t2.[ActualSalesValue])/(Select SUM(t.[ActualSalesValue]) FROM [_bvSTTransactionsFull] t) AS PoT
or:
SUM(t2.[ActualSalesValue])/(SUM(SUM(t2.[ActualSalesValue])) OVER() ) AS PoT
Note: you should use single quotes only for string and date constants, not for column and table names. If you need to escape names, use square braces.
I have an SQL table which has two integers. Let these integers be a and b.
I want to SELECT out a random record, such that the record is selected with probability proportional to C + a/b for some constant C which I will choose.
So for example, if C = 0, and there are two records with a=1,b=2 and a=2,b=3, then we have that for the first record C+a/b = 1/2 and for the second record C+a/b = 2/3, and therefore with probability 0.3 I will choose the first record, and probability 0.7 I will choose the second record from that SELECT query.
I know SQL well (I thought), but I am not even sure where to begin here. I thought of doing a select for the "SUM(a/b)" first, and then doing a select for the first record the sum of C+a/b up to it exceeds a random number between C*number_of_records + SUM(a/b) for the first time. But, I don't really know how to do that.
You could do something like sorting by a random number multiplied by your other stuff, and just select top 1 from that query - something like:
SELECT TOP 1 (your column names)
FROM (your table)
ORDER BY Rand() * (your calculation)