SQL, postgres. I have a csv input file with columns like avg. When i export how do i keep my digits?

Question

SQL, postgres. I have a csv input file with columns like avg with some values as 5,0 or 6,0. When i export back the file it writes 5 and 6 instead. How do i keep my digits?

Edit: im exporting using COPY

Answer 1

Use the numeric datatype. This type keeps the original scale of the input, scale being defined in this context as : count of decimal digits in the fractional part (see http://www.postgresql.org/docs/current/static/datatype-numeric.html)

Example:

CREATE TABLE num(n numeric);
INSERT INTO num VALUES (1.0), (2.30);

COPY num TO STDOUT;

Result:

1.0
2.30