Question about numeric

Hi,

when I import data from a text file (fildes are seperated with pipes) I get
an error for fields of type numeric if there are no data for this fields.

Example:

CREATE TABLE mytable (
id SERIAL,
num VARCHAR(32),
cost NUMERIC(6,2),
info TEXT
);

A line to import from a text file.

1|123abc||This part is....

Because of the empty field for the column cost, I get the following error:

ERROR: copy: line 1, Bad numeric input format ''
PQendcopy: resetting connection

This works (zero for the column cost):
1|123abc|0|This part is....

Thanks Erwin