I have a number with two digits after the decimal point; I try to cast this number using CAST for example:
Select SUM(CAST((123345.56) as decimal(28, 2))) * 100 AS AMOUNT
I get the following result
12334556.00
but I want get only 12334556 without displaying two digits after the decimal point.
Thank you.
It is not clear what you really want to do, but
SELECT SUM(CAST((123345.56 * 100.0) AS DECIMAL(28,0))) AS AMOUNT
gives 12334556.
When you use a number in the format 1234.56 it is a decimal literal in SQL Server: see "decimal constants" in Constants (Transact-SQL).
Integer data type is whole numbers, so cast your calculated value as int.
Select SUM(CAST((123345.56 * 100) as int)) AS AMOUNT
Related
I'm asked
I'm using a cast function to subtract the grosspay from the taxwitholding and making it the netpay. I'm trying to convert it into a decimal but im getting an integer
SELECT PerFrom, PerThru, EmpName, CAST(GrossPay AS decimal) AS Gross, CAST(TaxWitholding AS decimal) AS Taxes,
InsCost, (CAST(GrossPay AS decimal) - CAST(TaxWitholding AS decimal) - InsCost) AS NetPay
FROM vwPayCalc
WHERE PerFrom =
(SELECT MAX(PerFrom)
FROM vwPayCalc)
Specifying the DECIMAL type in CAST(... AS DECIMAL) without specifying the precision and scale, defaults to precision=18 and scale=0. In other words, a DECIMAL with zero decimal digits. More information in the documentation on numeric data types here.
It is never a good idea to rely on defaults; always specify the precision and scale required. Write something like CAST(... AS DECIMAL(18,2)) for instance.
I am trying to calculate a rate by using two variables from a subquery and i want my result to have three values after the decimal.
Variables:
calls -- type(integer)
boxes -- type(float)
ROUND((calls / boxes) * 100.0, 3) Call_Rate
only returns two decimal points
when i use
(CAST(calls AS DECIMAL(10,3)) / (boxes AS DECIMAL(10,3)) * 100.0 Call_Rate
this code returns three digits after the decimal but the third digit is always 0, so it is being rounded.
When converting both variables to float, it also returns just 2 values after decimal.
Is there any way to perform this operation to have it return 3 decimal points.
(CAST(calls AS DECIMAL(10,5)) / (boxes AS DECIMAL(10,5)) * 100.0 Call_Rate
When you multiply by 100, you are shifting the decimal point to the right two places, so you need two more places in your decimal conversion.
The 1st calculation actually rounds to three digits, but you probably run this query from SQL Assistant and there's a default precision of two. You can change it in Tools > Options > Number of decimal places to display for Float columns
The result of the 2nd calculation is based on Teradata's calculation rules for decimals, see DECIMAL Result Data Type
In short: Multiply first, then divide
100 * CAST(calls AS DECIMAL(10,3)) / CAST(boxes AS DECIMAL(10,3)) AS Call_Rate
Or keep the Float and do a final cast:
cast( 100 * calls / boxes as decimal(10,3))
I am looking for a division result that is extremely accurate.
This SQL returns the following results:
SELECT (CAST(297282.26 AS DECIMAL(38, 30)) / CAST(495470.44 AS DECIMAL(38, 30))) AS ResultDecimal
SELECT (CAST(297282.26 AS FLOAT) / CAST(495470.44 AS FLOAT)) AS ResultFloat
Here is the accurate result from WolframAlpha:
http://www.wolframalpha.com/input/?i=297282.26%2F495470.44
I was under the impression that DECIMAL would be more accurate than FLOAT:
"Because of the approximate nature of the float and real data types, do not use these data types when exact numeric behavior is required, such as in financial applications, in operations involving rounding, or in equality checks. Instead, use the integer, decimal, money, or smallmoney data types."
https://technet.microsoft.com/en-us/library/ms187912(v=sql.105).aspx
Why does the FLOAT calculation give me a result more accurate than when using DECIMAL?
I found the best precision to be when you use:
SELECT (CAST(297282.26 AS DECIMAL(15, 9)) / CAST(495470.44 AS DECIMAL(24, 2))) AS ResultDecimal
This gives a result of
0.599999991926864496699338915153
I think the actual value (to 100 digits) is:
0.5999999919268644966993389151530412187657451370862810705720405842980259326873264124495499670979362562...
Please bear in mind SQL Server defines the maximum precision and scale for division as:
max precision = (p1 - s1 + s2) + MAX(6, s1 + p2 + 1) -- up to 38
max scale = MAX(6, s1 + p2 + 1)
Where p1 & p2 are the precision of the two numbers and s1 & s2 are the scale of the numbers.
In this case the maximum precision is (15-9+2) + MAX(6, 9+24+1) = 8 + 34 = 42.
However SQL Server only allows a maximum precision of 38.
The maximum scale = MAX(6, 9+24+1) = 34
Hopefully you already understand that just because the FLOAT version presents more numbers after the decimal point, doesn't necessarily mean that those are the true numbers. This is about precision, not accuracy.
It is the CAST function itself that causes this loss of precision, not the difference between the FLOAT and DECIMAL data types.
To demonstrate this, compare your previous results to the result of this:
SELECT 297282.26 / 495470.44 AS ResultNoCast
In my version of the query, the presence of a decimal point in the literal numbers tells SQL Server to treat the values as DECIMAL datatype, with appropriate length and precision as determined by the server. The result is more precise than when you CAST explicitly to DECIMAL.
A clue to the reason for this can be found hidden in the official documentation of the CAST function, under Truncating and Rounding Results:
When you convert data types that differ in decimal places, sometimes the result value is truncated and at other times it is rounded. The following table shows the behavior.
From | To | Behavior
numeric | numeric | Round
So the fact that each separate literal value is treated as a NUMERIC (same thing as DECIMAL) on the way in, and is being casted to NUMERIC, causes rounding.
Anticipating your next question a little, if you want a more precise result from the NUMERIC/DECIMAL datatype, you just need to tell SQL Server that each component of the calculation is more precise:
SELECT 297282.26000000 / 495470.44000000 AS ResultSuperPrecise
This appears (from experimentation) to be the most precise I can get: either adding or removing a 0 from either the numerator or denominator makes the result less precise. I'm at a loss to explain why that is, because the result is only 23 digits to the right of the decimal point.
It doesn't give you a more accurate result. I say that because the value is an approximate and not all values will be available to stored in a float. On the other side of that coin though is that float has the possibility of a lot more precision. The maximum precision of a decimal/numeric is 38. https://msdn.microsoft.com/en-us/library/ms187746.aspx
When you look at float though the maximum precision is 53. https://msdn.microsoft.com/en-us/library/ms173773.aspx
Okay, here is what I think is going on.
#philosophicles - I think you are right in that the CAST is causing the problem, but not because I am trying to "convert data types that differ in decimal places".
When I execute the following statement
SELECT CAST((297282.26 / 495470.44) AS DECIMAL(38, 30)) AS ResultDecimal
The accurate result for the calculation is
This has way more than 30 digits after the decimal point, and my data type has scale set to 30. So the CAST rounds the value, then just adds zeros to the end until there are 30 digits. We end up with this:
So the interesting thing is how does the CAST determine up to how many decimals to round or truncate the output? I am not sure, but as #philosophicles pointed out, the scale of the input effects the rounding applied on the output.
SELECT CAST(((297282.26/10000) / (495470.44/10000)) AS DECIMAL(38, 30)) AS ResultDecimal
Thoughts?
Also interesting:
However, in simple terms, precision is lost when the input scales are
high because the result scales need to be dropped to 38 with a
matching precision drop.
https://dba.stackexchange.com/questions/41743/automatic-decimal-rounding-issue
The precision and scale of the numeric data types besides decimal are fixed.
https://dba.stackexchange.com/questions/41743/automatic-decimal-rounding-issue
I was trying to round some fields. When I have 59 days, I want to change it to 60.
The problem is that when I use this code, the 59 is changed to 30 because the round it is 1.
select round(1.9666,0)*30, round(59/30,0)*3'
The result of that query is 60 for the first field and 30 for the second one. The problem is that when I've tried:
select 59/30
The result is 1 and I need the entire answer that is 1.9666...
How can I make it?
Because the number you are dividing by is an INT (the data type of the left side is irrelevant), SQL Server will return an INT as the answer.
If you want a number with a decimal place as your result, you'll need to divide by one.
Don't cast to a FLOAT as the answer is probably not what you want (floats are generally not accurate and are 'approximations'):
SELECT 59 / CAST(30 AS FLOAT) -- = 1.96666666666667
CAST the right-hand side of the division to a DECIMAL:
SELECT 59 / CAST(30 AS DECIMAL(10, 2)) -- = 1.96666
SELECT cast(59 AS FLOAT) / cast(30 AS FLOAT)
Because the original figures are whole numbers, SQL presumes you want a whole number output.
To ensure you get one with the decimal places, you need to first change the data type from an integer int to a floating point float.
This is what the CAST command does.
EDIT: Commenter suggests you cast to DECIMAL instead. The principle is the same, but you need to supply more arguments. To cast to a decimal use something like:
cast(59 as DECIMAL(18, 3))
The first argument (the 18) is the total number of figures you want to permit in the decimal. The second argument (the 3) is the number you want after the decimal point.
The suggestion that it's more accurate is correct - as you'll see if you run the SELECT statements in this answer one after the other. But in this particular case, it only makes a tiny difference.
Using T-SQL and Microsoft SQL Server I would like to specify the number of decimal digits when I do a division between 2 integer numbers like:
select 1/3
That currently returns 0. I would like it to return 0,33.
Something like:
select round(1/3, -2)
But that doesn't work. How can I achieve the desired result?
The suggestions from stb and xiowl are fine if you're looking for a constant. If you need to use existing fields or parameters which are integers, you can cast them to be floats first:
SELECT CAST(1 AS float) / CAST(3 AS float)
or
SELECT CAST(MyIntField1 AS float) / CAST(MyIntField2 AS float)
Because SQL Server performs integer division. Try this:
select 1 * 1.0 / 3
This is helpful when you pass integers as params.
select x * 1.0 / y
It's not necessary to cast both of them. Result datatype for a division is always the one with the higher data type precedence. Thus the solution must be:
SELECT CAST(1 AS float) / 3
or
SELECT 1 / CAST(3 AS float)
use
select 1/3.0
This will do the job.
I understand that CASTing to FLOAT is not allowed in MySQL and will raise an error when you attempt to CAST(1 AS float) as stated at MySQL dev.
The workaround to this is a simple one. Just do
(1 + 0.0)
Then use ROUND to achieve a specific number of decimal places like
ROUND((1+0.0)/(2+0.0), 3)
The above SQL divides 1 by 2 and returns a float to 3 decimal places, as in it would be 0.500.
One can CAST to the following types: binary, char, date, datetime, decimal, json, nchar, signed, time, and unsigned.
Looks like this trick works in SQL Server and is shorter (based in previous answers)
SELECT 1.0*MyInt1/MyInt2
Or:
SELECT (1.0*MyInt1)/MyInt2
Use this
select cast((1*1.00)/3 AS DECIMAL(16,2)) as Result
Here in this sql first convert to float or multiply by 1.00 .Which output will be a float number.Here i consider 2 decimal places. You can choose what you need.
If you came here (just like me) to find the solution for integer value, here is the answer:
CAST(9/2 AS UNSIGNED)
returns 5
I was surprised to see select 0.7/0.9 returning 0.8 in Teradata given they're already as floats/decimal numbers! I had to do cast(0.7 as float) to get the output that I was after.
When using literals, the best way is to "tell" SQL
which type you mean.
if you want a decimal result, add decimal point ".0" to your numbers:
SELECT 1.0 / 3.0
Result
0.333333
if you want a float (real) result, add "e0" to your numbers:
SELECT 1e0 / 3e0
Result
0.333333333333333