Calculate Percentage using query in SQL Server - sql

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.

Related

How to calculate a bank's deposit growth from one call report to the next, as a percentage?

I downloaded the entire FDIC bank call reports dataset, and uploaded it to BigQuery.
The table I currently have looks like this:
What I am trying to accomplish is adding a column showing the deposit growth rate since the last quarter for each bank:
Note:The first reporting date for each bank (e.g. 19921231) will not have a "Quarterly Deposit Growth". Hence the two empty cells for the two banks.
I would like to know if a bank is increasing or decreasing its deposits each quarter/call report (viewed as a percentage).
e.g. "On their last call report (19921231)First National Bank had deposits of 456789 (in 1000's). In their next call report (19930331)First National bank had deposits of 567890 (in 1000's). What is the percentage increase (or decrease) in deposits"?
This "_%_Change_in_Deposits" column would be displayed as a new column.
This is the code I have written so far:
select
SFRNLL.repdte, SFRNLL.cert, SFRNLL.name, SFRNLL.city, SFRNLL.county, SFRNLL.stalp, SFRNLL.specgrp AS `Loan_Specialization`, SFRNLL.lnreres as `_1_to_4_Residential_Loans`, AL.dep as `Deposits`, AL.lnlsnet as `loans_and_leases`,
IEEE_DIVIDE(SFRNLL.lnreres, AL.lnlsnet) as SFR2TotalLoanRatio
FROM usa_fdic_call_reports_1992.All_Reports_19921231_1_4_Family_Residential_Net_Loans_and_Leases as SFRNLL
JOIN usa_fdic_call_reports_1992.All_Reports_19921231_Assets_and_Liabilities as AL
ON SFRNLL.cert = AL.cert
where SFRNLL.specgrp = 4 and IEEE_DIVIDE(SFRNLL.lnreres, AL.lnlsnet) <= 0.10
UNION ALL
select
SFRNLL.repdte, SFRNLL.cert, SFRNLL.name, SFRNLL.city, SFRNLL.county, SFRNLL.stalp, SFRNLL.specgrp AS `Loan_Specialization`, SFRNLL.lnreres as `_1_to_4_Residential_Loans`, AL.dep as `Deposits`, AL.lnlsnet as `loans_and_leases`,
IEEE_DIVIDE(SFRNLL.lnreres, AL.lnlsnet) as SFR2TotalLoanRatio
FROM usa_fdic_call_reports_1993.All_Reports_19930331_1_4_Family_Residential_Net_Loans_and_Leases as SFRNLL
JOIN usa_fdic_call_reports_1993.All_Reports_19930331_Assets_and_Liabilities as AL
ON SFRNLL.cert = AL.cert
where SFRNLL.specgrp = 4 and IEEE_DIVIDE(SFRNLL.lnreres, AL.lnlsnet) <= 0.10
The table looks like this:
Additional notes:
I would also like to view the last column (SFR2TotalLoansRatio) as a percentage.
This code runs correctly, however, previously I was getting a "division by zero" error when attempting to run 50,000 rows (1992 to the present).
Addressing each of your question individually.
First) Retrieving SFR2TotalLoanRatio as percentage, I assume you want to see 9.988% instead of 0.0988 in your results. Currently, in BigQuery you can achieve this by casting the field into a STRING then, concatenating the % sign. Below there is an example with sample data:
WITH data as (
SELECT 0.0123 as percentage UNION ALL
SELECT 0.0999 as percentage UNION ALL
SELECT 0.3456 as percentage
)
SELECT CONCAT(CAST(percentage*100 as String),"%") as formatted_percentage FROM data
And the output,
Row formatted_percentage
1 1.23%
2 9.99%
3 34.56%
Second) Regarding your question about the division by zero error. I am assuming IEEE_DIVIDE(arg1,arg2) is a function to perform the division, in which arg1 is the divisor and arg2 is the dividend. Therefore, I would adivse your to explore your data in order to figured out which records have divisor equals to zero. After gathering these results, you can determine what to do with them. In case you decide to discard them you can simply add within your WHERE statement in each of your JOINs: AL.lnlsnet = 0. On the other hand, you can also modify the records where lnlsnet = 0 using a CASE WHEN or IF statements.
UPDATE:
In order to add this piece of code your query, you u have to wrap your code within a temporary table. Then, I will make two adjustments, first a temporary function in order to calculate the percentage and format it with the % sign. Second, retrieving the previous number of deposits to calculate the desired percentage. I am also assuming that cert is the individual id for each of the bank's clients. The modifications will be as follows:
#the following function MUST be the first thing within your query
CREATE TEMP FUNCTION percent(dep INT64, prev_dep INT64) AS (
Concat(Cast((dep-prev_dep)/prev_dep*100 AS STRING), "%")
);
#followed by the query you have created so far as a temporary table, notice the the comma I added after the last parentheses
WITH data AS(
#your query
),
#within this second part you need to select all the columns from data, and LAG function will be used to retrieve the previous number of deposits for each client
data_2 as (
SELECT repdte, cert, name, city, county, stalp, Loan_Specialization, _1_to_4_Residential_Loans,Deposits, loans_and_leases, SFR2TotalLoanRatio,
CASE WHEN cert = lag(cert) OVER (PARTITION BY id ORDER BY d) THEN lag(Deposits) OVER (PARTITION BY id ORDER BY id) ELSE NULL END AS prev_dep FROM data
)
SELECT repdte, cert, name, city, county, stalp, Loan_Specialization, _1_to_4_Residential_Loans,Deposits, loans_and_leases, SFR2TotalLoanRatio, percent(Deposits,prev_dep) as dept_growth_rate FROM data_2
Note that the built-in function LAG is used together with CASE WHEN in order to retrieve the previous amount of deposits per client.

Add new column that finds percentage off value in existing column

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

SQL Server Floating Point in WHERE clause

I'm trying to query a database, I need to get a list of customers where their weight is equal to 60.5. The problem is that 60.5 is a real I've never query a database with a real in a where clause before.
I've tried this:
SELECT Name FROM Customers WHERE Weight=60.5
SELECT Name FROM Customers WHERE Weight=cast(60.5 as real)
SELECT Name FROM Customers WHERE Weight=cast(60.5 as decimal)
SELECT Name FROM Customers WHERE Weight=convert(real,'60.5')
SELECT Name FROM Customers WHERE Weight=convert(decimal,'60.5')
These queries return 0 values but in the Customers table their are 10 rows with Weight=60.5
Your problem is that floating point numbers are inaccurate by definition. Comparing what seems to be 60.5 to a literal 60.5 might not work as you've noticed.
A typical solution is to measure the difference between 2 values, and if it's smaller then some predefined epsilon, consider them equal:
SELECT Name FROM Customers WHERE ABS(Weight-60.5) < 0.001
For better performance, you should actually use:
SELECT Name FROM Customers WHERE Weight BETWEEN 64.999 AND 65.001
If you need equality comparison, you should change the type of the column to DECIMAL. Decimal numbers are stored and compared exactly, while real and float numbers are approximations.
#Amit's answer will work, but it will perform quite poorly in comparison to my approach. ABS(Weight-60.5) < 0.001 is unable to use index seeks. But if you convert the column to DECIMAL, then Weight=60.5 will perform well and use index seeks.

SQL Percentage of Occurrences

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

SQL: Calculate Percentage in new column using another column

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.