Query number of decimal places in a sql server resultset - sql-server

I have a table which contains a field of type numeric(28,10). I would like to display the records with a monospaced font, and a matching number of decimal places so that they line up when right aligned.
Is there any way to figure out the maximum number of decimal places that can be found in a given result set so that I can format accordingly as I display each record?
Edit: sorry, I should have been clearer ... if the result set contains numbers with only 3 decimal places, then all of the numbers should have only 3 decimal places (padded with zeroes).

The monospaced font is entirely a presentation issue...
I don't see your need for right alignment when I test:
CREATE TABLE [dbo].[Table_1](
[num] [numeric](28, 10) NOT NULL
)
INSERT INTO [example].[dbo].[Table_1] VALUES (1.1234567890);
INSERT INTO [example].[dbo].[Table_1] VALUES (1.123456789);
INSERT INTO [example].[dbo].[Table_1] VALUES (1.1234567);
SELECT [num]
FROM [example].[dbo].[Table_1]
...returns:
num
---------------
1.1234567890
1.1234567890
1.1234567000
So the question is--what are you trying to do that isn't giving you the output you desire?

Where do you want to display the results? Query Analyzer? In an application?
You can either
a) format the column to have a
finite number (known in advance) of
digits to the right of the decimal
point, truncating at that position;
this is the typical practice or
b) read through all of the rows in the
resultset to determine the value
with the greatest number of digits
to the right of the decimal point
(casting to string, splitting the
value using the decimal point as
delimiter, and getting the length of
the decimal-fraction string)
If for some reason option a) is unacceptable then you'd have do do b) procedurally, either server-side in a stored procedure or client-side in your client program.

Related

Limit number of positions after decimal point in MariaDB

I am currently making a small MariaDB database and ran into the following problem:
I want to save a floatingpoint number with only 2 poistions after the decimal point but everything before the decimal point should be unaffected.
For example: 1.11; 56789.12; 9999.00; 999999999999.01 etc.
I have done some research and this is what I am using right now:
CREATE TABLE mytable (
mynumber DOUBLE(10, 2)
)
The problem with this solution is that I also have to limit the number of positions before the decimal point, what I don't want to do.
So is there a possibility to limit the number of positions after the decimal point without affecting the positions before the decimal point or is there a "default number" I can use for the positions before the decimal point?
Don't use (m,n) with FLOAT or DOUBLE. It does nothing useful; it does cause an extra round.
DECIMAL(10,2) is possible; that will store numbers precisely (to 2 decimal places).
See also ROUND() and FORMAT() for controlling the rounding for specific values.
You had a mistake -- 999999999999.01 won't fit in DOUBLE(10,2), nor DECIMAL(10,2). It can handle only 8 (=10-2) digits to the left of the decimal point.
You can create a trigger that intercepts INSERT and UPDATE statements and truncates their value to 2 decimal places. Note, however, that due to how floating point numbers work at machine level, the actual number may be different.
Double precision numbers are accurate up to 14 significant figures, not a certain number of decimal points. Realistically, you need to detemine what is the biggest value you might ever want to store. Once you have done that, the DECIMAL type may be more appropriate for what you are trying to do.
See here for more details:
https://dev.mysql.com/doc/refman/8.0/en/precision-math-decimal-characteristics.html

Best method for storing a decimal number with varying number of decimal places

We need to store decimal numbers (unit prices) in a database table. The problem is that we need to store and display the same number of decimal places the end-user has given as user input. The maximum number of decimal places is 6. So, for example:
1.00
9.9999
0.123456
To start with, for example, DECIMAL(10,6) seems to always store the maximum number of decimals (6).
MONEY stores a varying number of decimals (2-4), but not more than 4 (and has some other issues, why we do not want to use it).
We know that formatting should always be done on the client that uses the data, but it would be nice, if we could query the data so that the query result would have the correct number of decimals automatically.
We are prepared for adding another column that stores the number of decimal places given by the user, and then use that column to format the data for display, but that sounds a bit complex.
If we add another column, is it possible to format the decimal value directly in the query using that column?
Two soutions I can think of:
As you've already mentioned, store it in text
Store it in decimal(19,6)
Store the number of decimals in another field, i.e. 3
Use a calculated column to render the format, i.e. FORMAT()
You'd need to reverse engineer the number of decimals though.
This is more complicated but at least you can store the number in a numeric field and have SSMS render what you want.
CREATE TABLE MyTable (
NumericValue DECIMAL(19,6) NOT NULL,
Decimals TINYINT NOT NULL,
Formatted AS (FORMAT(NumericValue,'#.' + LEFT('00000000',Decimals)))
)
INSERT INTO MyTable (NumericValue, Decimals)
SELECT 10.2,3 UNION ALL
SELECT 1.2,1 UNION ALL
SELECT 1,3
SELECT * FROM MyTable
We can use decimal by Storage LAW :
decimal (1,9) Storage bytes is 5
decimal (10,19) Storage bytes is 9
decimal (20,28) Storage bytes is 13
decimal (29,38) Storage bytes is 17
About Money :
If you have a sensitive business do not use MONEY.
Money does not need to save us.
For example: We discount the whole invoice. If we want to divide this value for rows in the future, a third decimal place is likely to be created. And if you use Mani this value should be truncated, which will result in a Trending error.
The use of decimals allows the error coefficient to be reduced.
you can know about decimal in DocMicrosoft

Arithmetic overflow error for type int, value = 4957500001.400178

I know that similar questions have been asked again in the past, but I think my case is slightly different. I have a column which has Logarithmic values and I'm trying to invert them using the following formula:
SELECT POWER(10,CAST(9.695262723 AS NUMERIC(30,15)))
Let's say the value 9.695262723 is one of the values of that column.
When trying to run this query I get an Arithmetic overflow error for type int, value = 4957500001.400178.
On the other hand, the same query works fine for smaller values e.g. SELECT POWER(10,CAST(8.662644523 AS NUMERIC(30,15)))
How could I overcome that error and calculate the inverse values of the log10 entries I have? Just for information the greater value that exists in the table (in log10 scale) is 12.27256096.
The problem here is your first input parameter (10) which SQL server will, by default, treat as the datatype int.int has a maximum value of 2^31-1 (2,147,483,647), and the number 4,957,500,001 is far larger than this, so you need to use a bigint:
SELECT POWER(CONVERT(bigint,10),CONVERT(numeric(30,15),9.695262723));
Edit: If you need to retain the decimal places, then use a numeric with a large enough scale and precision, instead of bigint.

Binary data different when viewed with CFDUMP

I have a SQL Server database that has a table that contains a field of type varbinary(256).
When I view this binary field via a query in MMS, the value looks like this:
0x004BC878B0CB9A4F86D0F52C9DEB689401000000D4D68D98C8975425264979CFB92D146582C38D74597B495F87FEA09B68A8440A
When I view this same field (and same record) using CFDUMP, the value looks like this:
075-56120-80-53-10279-122-48-1144-99-21104-1081000-44-42-115-104-56-10584373873121-49-714520101-126-61-115116891237395-121-2-96-101104-886810
(For the example below, the original binary value will be #A, and the CFDUMP value above will be #B)
I have tried using CAST(#B as varbinary(256)) but didn't get the same value as #A.
What must I do to convert the value retrieved from CFDUMP into the correct binary representation?
Note: I no longer have the applicable records in the database. I need to convert #B into the correct value that can re-INSERT into a varbinary(256) field.
(Expanded from comments)
I do not mean this sarcastically, but what difference does it make how they display binary? It is simply a difference in how the data is presented. It does not mean the actual binary values differ.
It is similar to how dates are handled. Internally, they are a big numbers. But since most people do not know which date 1234567890 represents, applications chose to display the number in a more human friendly format. So SSMS might present the date as 2009-02-13 23:31:30.000, while CF might present it as {ts '2009-02-13 23:31:30'}. Even though the presentations differ, it still the same value internally.
As far as binary goes, SSMS displays it as hexadecimal. If you use binaryEncode() on your query column, and convert the binary to hex, you can see it is the same value. Just without the leading 0x:
writeDump( binaryEncode(yourQuery.binaryColumn, "hex") )
If you are having some other issue with binary, could you please elaborate?
Update:
Unfortunately, I do not think you can easily convert the cfdump representation back into binary. Unlike Railo's implementation, Adobe's cfdump just concatenates the numeric representation of the individual bytes into one big string, with no delimiter. (The dashes are simply negative numbers). You can reproduce this by looping through the bytes of your sample string. The code below produces the same string of numbers you posted.
bytes = binaryDecode("004BC878B0CB9A4F...", "hex");
for (i=1; i<=arrayLen(bytes); i++) {
WriteOutput( bytes[i] );
}
I suppose it is theoretically possible to convert that string into binary, but it would be very difficult. AFAIK, there is no way to accurately determine where one number (or byte) begins and the other ends. There are some clues, but ultimately it would come down to guesswork.
Railo's implementation, displays the byte values separated by a dash "-". Two consecutive dashes indicates a negative number. ie "0", "75", "-56", ...
0-75--56-120--80--53--102-79--122--48--11-44--99--21-104--108-1-0-0-0--44--42--115--104--56--105-84-37-38-73-121--49--71-45-20-101--126--61--115-116-89-123-73-95--121--2--96--101-104--88-68-10
So you could probably parse that string back into an array of bytes. Then insert the binary into your database using <cfqueryparam cfsqltype="CF_SQL_BINARY" ..>. Unfortunately that does not help you, but the explanation might help the next guy.
At this point, I think your best bet is to just restore the data from a database backup.

SQL Server adding trailing zeros to result of division

Has anyone encountered the following where when you divide a number in SQL a random number of trailing zeros are appended?...
SELECT 8.95/10 ... results in 0.895000
If you have encountered this, what is the reason for the addition of the zeros?
UPDATE: I am aware that casting the result to FLOAT will remove the 0's
First of all, seeing trailing zeros or anything when querying in SSMS is not because it's something special with the DB engine, but it's always the result of the internal query result formating used for displaying. After all, all numbers are just binary values in some representation that at some point gets translated to strings for displaying.
Anyway, the real reason is because of the datatypes involved, and how SSMS decides to display them. When doing those calculations, SQL Server must decide what datatype the result will be, based on the types of the inputs, and in that particular case it was numeric(7,6). You can easily see the result types by saving the result to a temp table and running sp_columns on that:
SELECT 8.95 AS dividend,10 AS divider,8.95/10 AS result INTO #temp ;
EXEC tempdb..sp_columns '#temp' ;
SELECT * FROM #temp ;
DROP TABLE #temp ;
In my case it returned this (among other uninteresting things for now):
COLUMN_NAME TYPE_NAME PRECISION LENGTH SCALE
dividend numeric 3 5 2
divided int 10 4 0
result numeric 7 9 6
Playing with castings in various places in the division will only change the resulting data types. The interesting fact is the Scale for the result column, note that it's a 6. That's exactly the number of decimal places that SSMS decides to display for the NUMERIC data type, regardless of the actual value. FLOAT don't have this formating from SSMS, which is why the casting eliminates the trailing zeros. Of course, when using the DB from outside SSMS, the formating will depend on the calling application and will not be subject to all this.
As another example of this behavior, just try SELECT CAST(1 AS NUMERIC(18,10)) and see that it shows 1.0000000000.

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