What does double [3,2] mean? Is it formatting?
double [3,2] means than values can be stored with up to 3 digits in total, of which 2 digits may be after the decimal.
The maximum number of digits may be specified as the first parameter.
The maximum number of digits to the right of the decimal point is specified in the last parameter.
Related
What is difference between the Ceiling and Round functions in in SQL Server?
I have some query and I get a totally different value in Round and Ceiling function.
The answer is here
Round does a standard rounding. If value is .5 or over then you get back 1. If it’s less than .5 you get back 0
Ceiling returns the integer equal to or higher than the value passed in.
SELECT ROUND(235.400,0);
Answer= 235.000
SELECT CAST(ROUND(235.400,0) as int)
Answer= 235
Round allows decimal values to round the value.
It will take next value if decimal value is only greater than or equal to 5.
Ceiling no need to decimal values.
It will take the next value of the given number. If decimal value is even less than 5.
ROUND let's you round values in a standard way (round up from values 5 or higher, round down otherwise). It also takes number of decimal places you want to round to, so if you want to get an integer, you just pass 0 as number of decimal places. See documentation.
CEILING is operation, which return the smallest integer greater than passed number, so it rounds up to next integer.
CONLUSION:
So basic difference: CEILING rounds up, while ROUND rounds number in standard way.
Another key difference is that ROUND let's you specify number of decimal places you want round to.
I have a column in a table whose datatype is number(3,2).
I try to insert 22.3 into this column and it gives me an error stating that value larger than specified precision.
My point is that 22.3 has a precision of 3. Then why doesn't it accept this as a value?
Quoted from Oracle's documentation:
Optionally, you can also specify a precision (total number of digits) and scale (number of digits to the right of the decimal point)
So NUMBER(3,2) allows a total of 3 digits, 2 of which are to the right of the decimal point, leaving only one to the left of it. In other words, the largest number that could fit into this column is 9.99.
When we do Ceiling(convert(decimal,8.09)) then result is 8 and in Ceiling(convert(float,8.09)) result is 9, explain?
A DECIMAL Type in SQL Uses a Precision numeric data type instead of an Approximate numeric data type like a FLOAT. What this implies is that the data stores not only the number but a dimension of how precise it can be, whilst in comparison a float is always a scaled approximation store for a numeric value.
There are 3 pieces to the DECIMAL precision, the value, the P number (for precision) and S number (for scale). The P number is the maximum number of digits that the data type can store so if I have a DECIMAL with a precision of 4 I can only go upto 9999 or as low as 0.001. The default is 18 digits.
The problem you are having is your S number. The S number is the precision of the numbers after the decimal point, a sort of sub-set maximum on top of the P number. So a S precision of 2 means I can have .01 to .99, precision of 4 is .0001 to .9999 and so on. This in combination with P can lead to truncation if you don't account for the maximum digits. So although a conversion of the number 12345.12345 (P,S) = (6,3) should have the 3 decimal digits (12345.123), the maximum digits are 6 so you end up with (12345.1) In order to have an S number the P number must also be declared:
DECIMAL(P[,S])
In this way, due to the construction limits of P and S, P cannot be smaller than S and S not smaller than 0 (you cannot have 14 decimal places in a number which the maximum digits is only 5) :
P >= [S] >= 0
To solve your problem, when you do your CONVERT, declare how precise you need your decimal to be as, by default, the S value is set to 0 :
SELECT CONVERT(DECIMAL(18,6), 8.09)
Here are a few examples to show the precision, run them and see how they work:
SELECT CONVERT(DECIMAL(10,1) , 12.345678) --10 Maximum Digits, 1 Decimal Places (Expect round off)
SELECT CONVERT(DECIMAL(18,3) , 12.2345) --18 Maximum Digits, 3 Decimal Places (Expect 3rd decimal round up)
SELECT CONVERT(DECIMAL(3,4) , 123.456789) --3 Maximum Digits, 4 Decimal Places (Expect 4th decimal round up, but get overflow error as P < S )
SELECT CONVERT(DECIMAL(18,6) , 8.09) --18 Maximum Digits, 6 Decimal Places (Expect no data change in precision)
I hope that helps you out, if possible always use decimal and specify a precision where you know there are bounds. It can be more efficient depending on the data and nature of the procedure.
This is a precision issue.
Because
convert(decimal,8.09) == 8
whereas
convert(float,8.09) == 8.09
decimal has a default precision of 18
float is float(53) (also a synonym for double) which has 15 digit precision
What are you actually trying to do? What is the context?
I am using SQL Server 2008 express, any reason??
however, if i convert to decimal(6,4) is work. e.g. Select CONVERT(decimal(6,4),'1.1234');
thanks you.
decimal(x,y)
x: total number of digits(max)
y: number of digits after decimal point(max)
thats why y<=x
decimal(Precision, Scale). The Precision number control the maximum number of digits on the left side of the period. The Scale specifies the maximum number of digits on the right side.
If you want 3 digits before decimal and 4 after decimal then
rate decimal(7, 4)
I need to do a data migration from a data base and I'm not too familiar with databases so I would like some clarification. I have some documentation that could apply to either an Oracle or a SQL database and it has a column defined as NUMBER(10,5). I would like to know what this means. I think it means that the number has 10 digits with 5 after the decimal point, but I would like clarification. Also would this be different for either SQL or Oracle?
The first number is precision the second number is scale. The equivalent in SQL Server can be as Decimal / Numeric and you could define it like so:
DECLARE #MyDec decimal(18,2)
The 18 is the max total number of decimal digits that can be stored (that is the total number of digits, for instance 123.45 the precision here is 5, while the scale is 2). The 2 is the scale and it specifies the max number of digits stored to the right of the decimal point.
See this article
Just remember the more precision the more size in storage bytes. So keep it at a minimum if possible.
p (precision)
Specifies the maximum total number of
decimal digits that can be stored,
both to the left and to the right of
the decimal point. The precision must
be a value from 1 through the maximum
precision. The maximum precision is
38. The default precision is 18.
s (scale)
Specifies the maximum number of
decimal digits that can be stored to
the right of the decimal point. Scale
must be a value from 0 through p.
Scale can be specified only if
precision is specified. The default
scale is 0; therefore, 0 <= s <= p.
Maximum storage sizes vary, based on
the precision.
Finally, it is worth mentioning that in oracle you can define a scale greater then a precision, for instance Number(3, 10) is valid in oracle. SQL Server on the other hand requires that the precision >= scale. So if you defined Number(3,10) in oracle, it would map into sql as Number(10,10).
Defining a column in Oracle as NUMBER(10,5) means that the column value can have a decimal of up to five places of precision, and ten digits in overall length. If you insert a value into the column that does not have any decimal places defined, the maximum the column will support is 10 digits. For example, these values will be supported by the column defined as NUMBER(10,5):
1234567890
12345.67890
It made validation a pain.
MySQL and SQL Server don't support the NUMBER data type - to support decimals, you're looking at using DECIMAL (or FLOAT?). I haven't looked at PostgreSQL, but I would figure it to be similar to Oracle.
In Oracle, a column defined as NUMBER(4,5) requires a zero for the first digit after the decimal point and rounds all values past the fifth digit after the decimal point.
From the Oracle documentation
NUMBER(p,s)
where: p is the precision, or the
total number of digits. Oracle
guarantees the portability of numbers
with precision ranging from 1 to 38. s
is the scale, or the number of digits
to the right of the decimal point. The
scale can range from -84 to 127.
Here are some examples :
Actual data .000127 stored in NUMBER(4,5) becomes .00013
Actual data 7456123.89 stored in NUMBER(7,-2) becomes 7456100
Edited
JonH mentions something noteworthy:
Oracle allows the scale > precision,
so SQL will map that so that if s>p
then p becomes s. That is NUMBER(3, 4)
in oracle becomes NUMERIC(4,4) in SQL.