sql int to decimal with no storage - sql

I am currently writing in MS-SQL to convert old data to a new table and one of the variable in the old table is a int. In the new table it has to be a decimal(10,3) because of the data now being entered. The old data also has some nulls also. When I convert the data using round to generate the new decimal I get a error:
Msg 8115, Level 16, State 8, Line 1
Arithmetic overflow error converting int to data type numeric.
using the following code:
insert into Data_Exchange_Claims_History (Qty_Dispense)
select convert(decimal(10,3),round(ISNULL(Qty_Dispense, 0), 3))
from dbo.Data_Exchange_Claims_History_old c

I assume the question is how it can fail;
An INT won't always fit into a DECIMAL(10,3).
DECIMAL(10,3) means a total of 10 digits, of which 3 are to the right of the decimal point.
In other words, it can only represent integers up to 9999999.

An INT can fit into DECIMAL 10,3 only if it is <= 9,999,999
9,999,999 will turn into 9,999,999.000 (10 total digits, 3 decimals).

After playing with the problem for a while it dawned on me that I just needed to move the decimal over three places so I divided the numbers by 1000 and it worked. The new query looks like:
insert into Data_Exchange_Claims_History (Qty_Dispense)
select convert(decimal(10,3),(Qty_Dispense/1000))
from dbo.Data_Exchange_Claims_History_old c
Thanks to everyone who contributed to this as it helped me look at the problem in a new light.

Related

Char to Decimal

I am trying to multiply two fields together. Problem is, one is CHAR and one is DECIMAL.
OEAUDD.QTYSHIPPED = DECIMAL
LITERS.[VALUE] = CHAR
(This column holds more than just numbered values so I'm not able to permanently change the data type in that column. However, all of the data I'm pulling is numerical only and I need to be able to multiply it by qtyshipped)
Original code:
CONVERT (DOUBLE PRECISION, TABLENAME.QTYSHIPPED*LITERS.[VALUE]) AS 'TotalLitersSold'
This was working fine for a while and then suddenly started throwing error:
Msg 8114, Level 16, State 5, Line 3
Error converting data type varchar to numeric
Attempted:
CONVERT (DECIMAL,LITERS.[VALUE])
and got the same error.
Attempted:
CAST (LITERS.[VALUE] AS DECIMAL)
and got the same error.
Is there any way to change the data type of this column to decimal so I can multiply the two values together?
Thank you in advance for the assistance.
Use TRY_CONVERT() and use it on each value separately:
(TRY_CONVERT(DOUBLE PRECISION, TABLENAME.QTYSHIPPED) *
TRY_CONVERT(DOUBLE PRECISION, LITERS.[VALUE])
)

With TSQL, how do I convert a highly precise value to numeric?

I'm having a pretty common problem but my usual solution isn't working. I've got a highly precise value stored as a character in a staging table. When I push it to it's final destination, a column with data type numeric(38,38), it fails. I thought it was because of the negative sign, but when I get rid of it, I still have an issue. I've got the numeric column maxed out but I'm still getting the following error:
Arithmetic overflow error converting nvarchar to data type numeric.
Normally I just convert to float but that isn't working. Besides which, I want to retain the precision of the value and float appears to take that away.
What am I missing here?
DECLARE #Value NVARCHAR(255) = '-1.000000000000000'
SELECT CAST(#Value AS numeric(38,38))
DECLARE #Value NVARCHAR(255) = '-1.000000000000000'
SELECT CAST(CAST(#Value AS FLOAT) AS numeric(38,38))
CLARIFICATION:
numeric(38,38) are absurd parameters and were only used for testing and as an example for this question. The original column was set to numeric(16,15) which worked more than 99% of the time on a dataset of millions of records and thus didn't flag as an issue.
numeric(38,38) is a numeric value of 38 digits, 38 of which are after the decimal. Because of this, any number greater than 1 or less than -1 (has 1 or more digits to the left of the decimal) will overflow. You need to account for the maximum number of digits that may occur to both the left and the right of the decimal.
1.00001 would be numeric(6,5) with 6 digits, 5 of which are on the right of the decimal, 1 of which is on the left.
10.00001 would be numeric(7,5) with 7 digits, 5 of which are on the right of the decimal, 2 of which are on the left.

SQL: Unable to CAST a query

SELECT CAST ((SUM(r.SalesVolume)/1000) AS decimal(3,3)) FROM RawData r
The above is a part of a query that I am trying to run but returns an error:
Lookup Error - SQL Server Database Error: Arithmetic overflow error converting int to data type numeric.
Not sure what this means.
The result column looks like(Without dividing by 1000 and casting):
Total_Sales_Volume
64146
69814
68259
56318
66585
51158
44365
49855
49553
88998
102739
55713
Tried casting as float but doesnt help.
The Problem is decimal(3,3) --> this means a number with 3 digit, 3 of them behind the decimal point. If you want a number like this 1234567.123 you would have do declare it as decimal(10,3)
Try this:
SELECT CAST ((SUM(r.SalesVolume)/1000.0) AS decimal(6,3)) FROM RawData r
decimal(3,3) means that you allow numbers with 3 digits in total, and 3 of these are behind the comma ... I think you meant decimal(6,3)
EDIT: In addition, you need to to divide by 1000.0, not by 1000.
If you divide by 1000, it is an integer division.
If you divide by 1000.0, then it becomes a decimal division, with commas.
Try following:
SELECT CAST ((SUM(r.SalesVolume)/1000) AS numeric(6,3)) FROM RawData r

How do I count decimal places in SQL?

I have a column X which is full of floats with decimals places ranging from 0 (no decimals) to 6 (maximum). I can count on the fact that there are no floats with greater than 6 decimal places. Given that, how do I make a new column such that it tells me how many digits come after the decimal?
I have seen some threads suggesting that I use CAST to convert the float to a string, then parse the string to count the length of the string that comes after the decimal. Is this the best way to go?
You can use something like this:
declare #v sql_variant
set #v=0.1242311
select SQL_VARIANT_PROPERTY(#v, 'Scale') as Scale
This will return 7.
I tried to make the above query work with a float column but couldn't get it working as expected. It only works with a sql_variant column as you can see here: http://sqlfiddle.com/#!6/5c62c/2
So, I proceeded to find another way and building upon this answer, I got this:
SELECT value,
LEN(
CAST(
CAST(
REVERSE(
CONVERT(VARCHAR(50), value, 128)
) AS float
) AS bigint
)
) as Decimals
FROM Numbers
Here's a SQL Fiddle to test this out: http://sqlfiddle.com/#!6/23d4f/29
To account for that little quirk, here's a modified version that will handle the case when the float value has no decimal part:
SELECT value,
Decimals = CASE Charindex('.', value)
WHEN 0 THEN 0
ELSE
Len (
Cast(
Cast(
Reverse(CONVERT(VARCHAR(50), value, 128)) AS FLOAT
) AS BIGINT
)
)
END
FROM numbers
Here's the accompanying SQL Fiddle: http://sqlfiddle.com/#!6/10d54/11
This thread is also using CAST, but I found the answer interesting:
http://www.sqlservercentral.com/Forums/Topic314390-8-1.aspx
DECLARE #Places INT
SELECT TOP 1000000 #Places = FLOOR(LOG10(REVERSE(ABS(SomeNumber)+1)))+1
FROM dbo.BigTest
and in ORACLE:
SELECT FLOOR(LOG(10,REVERSE(CAST(ABS(.56544)+1 as varchar(50))))) + 1 from DUAL
A float is just representing a real number. There is no meaning to the number of decimal places of a real number. In particular the real number 3 can have six decimal places, 3.000000, it's just that all the decimal places are zero.
You may have a display conversion which is not showing the right most zero values in the decimal.
Note also that the reason there is a maximum of 6 decimal places is that the seventh is imprecise, so the display conversion will not commit to a seventh decimal place value.
Also note that floats are stored in binary, and they actually have binary places to the right of a binary point. The decimal display is an approximation of the binary rational in the float storage which is in turn an approximation of a real number.
So the point is, there really is no sense of how many decimal places a float value has. If you do the conversion to a string (say using the CAST) you could count the decimal places. That really would be the best approach for what you are trying to do.
I answered this before, but I can tell from the comments that it's a little unclear. Over time I found a better way to express this.
Consider pi as
(a) 3.141592653590
This shows pi as 11 decimal places. However this was rounded to 12 decimal places, as pi, to 14 digits is
(b) 3.1415926535897932
A computer or database stores values in binary. For a single precision float, pi would be stored as
(c) 3.141592739105224609375
This is actually rounded up to the closest value that a single precision can store, just as we rounded in (a). The next lowest number a single precision can store is
(d) 3.141592502593994140625
So, when you are trying to count the number of decimal places, you are trying to find how many decimal places, after which all remaining decimals would be zero. However, since the number may need to be rounded to store it, it does not represent the correct value.
Numbers also introduce rounding error as mathematical operations are done, including converting from decimal to binary when inputting the number, and converting from binary to decimal when displaying the value.
You cannot reliably find the number of decimal places a number in a database has, because it is approximated to round it to store in a limited amount of storage. The difference between the real value, or even the exact binary value in the database will be rounded to represent it in decimal. There could always be more decimal digits which are missing from rounding, so you don't know when the zeros would have no more non-zero digits following it.
Solution for Oracle but you got the idea. trunc() removes decimal part in Oracle.
select *
from your_table
where (your_field*1000000 - trunc(your_field*1000000)) <> 0;
The idea of the query: Will there be any decimals left after you multiply by 1 000 000.
Another way I found is
SELECT 1.110000 , LEN(PARSENAME(Cast(1.110000 as float),1)) AS Count_AFTER_DECIMAL
I've noticed that Kshitij Manvelikar's answer has a bug. If there are no decimal places, instead of returning 0, it returns the total number of characters in the number.
So improving upon it:
Case When (SomeNumber = Cast(SomeNumber As Integer)) Then 0 Else LEN(PARSENAME(Cast(SomeNumber as float),1)) End
Here's another Oracle example. As I always warn non-Oracle users before they start screaming at me and downvoting etc... the SUBSTRING and INSTRING are ANSI SQL standard functions and can be used in any SQL. The Dual table can be replaced with any other table or created. Here's the link to SQL SERVER blog whre i copied dual table code from: http://blog.sqlauthority.com/2010/07/20/sql-server-select-from-dual-dual-equivalent/
CREATE TABLE DUAL
(
DUMMY VARCHAR(1)
)
GO
INSERT INTO DUAL (DUMMY)
VALUES ('X')
GO
The length after dot or decimal place is returned by this query.
The str can be converted to_number(str) if required. You can also get the length of the string before dot-decimal place - change code to LENGTH(SUBSTR(str, 1, dot_pos))-1 and remove +1 in INSTR part:
SELECT str, LENGTH(SUBSTR(str, dot_pos)) str_length_after_dot FROM
(
SELECT '000.000789' as str
, INSTR('000.000789', '.')+1 dot_pos
FROM dual
)
/
SQL>
STR STR_LENGTH_AFTER_DOT
----------------------------------
000.000789 6
You already have answers and examples about casting etc...
This question asks of regular SQL, but I needed a solution for SQLite. SQLite has neither a log10 function, nor a reverse string function builtin, so most of the answers here don't work. My solution is similar to Art's answer, and as a matter of fact, similar to what phan describes in the question body. It works by converting the floating point value (in SQLite, a "REAL" value) to text, and then counting the caracters after a decimal point.
For a column named "Column" from a table named "Table", the following query will produce a the count of each row's decimal places:
select
length(
substr(
cast(Column as text),
instr(cast(Column as text), '.')+1
)
) as "Column-precision" from "Table";
The code will cast the column as text, then get the index of a period (.) in the text, and fetch the substring from that point on to the end of the text. Then, it calculates the length of the result.
Remember to limit 100 if you don't want it to run for the entire table!
It's not a perfect solution; for example, it considers "10.0" as having 1 decimal place, even if it's only a 0. However, this is actually what I needed, so it wasn't a concern to me.
Hopefully this is useful to someone :)
Probably doesn't work well for floats, but I used this approach as a quick and dirty way to find number of significant decimal places in a decimal type in SQL Server. Last parameter of round function if not 0 indicates to truncate rather than round.
CASE
WHEN col = round(col, 1, 1) THEN 1
WHEN col = round(col, 2, 1) THEN 2
WHEN col = round(col, 3, 1) THEN 3
...
ELSE null END

Encountered arithmetic overflow error using decimal datatype in SQL server 2008

I have a column declared as decimal(4,4). Currently it stores 0.0400 as the value. Now I need to update the value stored from 0.0400 to 9.95.I used the following query :
Update <tablename>
set <columnname>= 9.95
where <condition>
When I try to execute, I get the following error :
Arithmetic overflow error converting numeric to data type numeric.
The statement has been terminated.
Kindly help.
Defining a column as decimal(4,4) is the equivalent of saying
I will have 4 digits in total, of which 4 come after the decimal point
To represent 9.95, you'd need to store it as 9.9500 to satisfy the '4 decimal places' condition. But this now exceeds the 'max 4 digits' condition and so can't be converted.
You'd need at least decimal(5, 4) to store 9.95 as a decimal in this way.
If you write decimal(4,4), what the database hears is:
There are four digits total
All four of them are behind the decimal separator
So a decimal(4,4) can store the range 0.0000 to 0.9999 (and its negative equivalent). But 9.95 is outside that range, so it will return an error.
I had similar issue few years ago, here is my understanding.
Decimal(TotalDigitsIncludingDecimal,DecimalPlaces)
Eg: Value = 50.05 declare Decimal(4,2)
Eg: Value = 5000.0005 declare Decimal(8,4)
Decimal(6,2) means:
At most 4 digits to the left of the decimal point, since you can have 2 to the right of the decimal point. (even if you don't see them, or use them)
It is VERY wrong to say "you can have 6 digits total".
12345 is less than 6 digits total. But it'll overflow.
I'm not sure why SQL didn't just make it "Decimal(left, right)" and you would instantly see the limits you can store there.