The pg_catalog functions are the default ones, see at Guide the build-in math functions. Where float is synonymous of double precision and myschema is public when you not use a schema. Pg_catalog | round | numeric | numeric, int PS: the command \df round, on psql after overloadings, will show something like this table Other alternative, overloading ROUND function again, and using all range of accuracy-precision of a floating point number, is to return a float when the accuracy is defined (see IanKenney's answer), CREATE FUNCTION ROUND(Īccuracy float - accuracy, the "counting unit" An alternative is to use round(f,3)::float or to create a round_tofloat() function. In another applications we need a float also as result. The ROUND(float,int) function is f_round, it returns a (decimal) NUMERIC datatype, that is fine for some applications: problem solved! The FM prefix tells to_char that you don't want any padding with leading spaces. To_char will round numbers for you as part of formatting. Use to_char (see: data type formatting functions in the manual), which lets you specify a format and gives you a text result that isn't affected by whatever weirdness your client language might do with numeric values. If you're formatting for display to the user, don't use round. Just append ::numeric for the shorthand cast, like round(val::numeric,2). You must cast the value to be rounded to numeric to use the two-argument form of round. ![]() You can see that PostgreSQL is expanding it in the output). (In the above, note that float8 is just a shorthand alias for double precision. Regress=> SELECT round( CAST(float8 '3.1415927' as numeric), 2) Pg_catalog | round | numeric | numeric, integer | normal Pg_catalog | round | numeric | numeric | normal Pg_catalog | round | double precision | double precision | normal Pg_catalog | dround | double precision | double precision | normal Schema | Name | Result data type | Argument data types | Type regress=> SELECT round( float8 '3.1415927', 2 ) ĮRROR: function round(double precision, integer) does not exist For reasons Sherrill 'Cat Recall' explains in the comments, the version of round that takes a precision is only available for numeric. Now insert some products with the prices whose scales exceed the scale declared in the price column: INSERT INTO employee_salary(name, salary)Īs the scale of the price column is 2, PostgreSQL rounds the value 57896.2277 up to 57896.22 for Raju, the value 84561.3657 down to 84561.36 for Abhishek, the value 55100.11957 to 55100.12 for Nikhil and the value 49300.21425849 to 49300.21 for Ravi.PostgreSQL does not define round(double precision, integer). The below query returns all rows of the products table: SELECTĬreate a new table named products with the below commands: CREATE TABLE IF NOT EXISTS employee_salary( Now insert some products with the prices whose scales exceed the scale declared in the price column: INSERT INTO products (name, price)Īs the scale of the price column is 2, PostgreSQL rounds the value 100.2157 up to 100.22 and rounds the value 300.2149 down to 300.21 It is recommended to not use the NUMERIC type, if precision is not required as the calculation on NUMERIC values is slower than integers, floats, and double precision.Ĭreate a new table named products with the below commands: CREATE TABLE IF NOT EXISTS products ( The NUMERIC and DECIMAL types are equivalent in PostgreSQL and upto the SQL standard. If you eliminate both precision and scale, there is no limit to the precision or the scale and the syntax will be as below: Syntax: NUMERIC It is allowed to have a zero or positive scale, as the syntax defined below for a NUMERIC column with the scale of zero: Syntax: NUMERIC(precision) ![]() The NUMERIC value can have up to 131, 072 digits before the decimal point of 16, 383 digits after the decimal point. Scale: Number of digits in terms of a fraction.
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