8.2. Monetary Types
money type stores a currency amount with a fixed fractional precision; see Table 8.3. The fractional precision is determined by the database's lc_monetary setting. The range shown in the table assumes there are two fractional digits. Input is accepted in a variety of formats, including integer and floating-point literals, as well as typical currency formatting, such as
'$1,000.00'. Output is generally in the latter form but depends on the locale.
Table 8.3. Monetary Types
|8 bytes||currency amount||-92233720368547758.08 to +92233720368547758.07|
Since the output of this data type is locale-sensitive, it might not work to load
money data into a database that has a different setting of
lc_monetary. To avoid problems, before restoring a dump into a new database make sure
lc_monetary has the same or equivalent value as in the database that was dumped.
Values of the
bigint data types can be cast to
money. Conversion from the
double precision data types can be done by casting to
numeric first, for example:
However, this is not recommended. Floating point numbers should not be used to handle money due to the potential for rounding errors.
money value can be cast to
numeric without loss of precision. Conversion to other types could potentially lose precision, and must also be done in two stages:
Division of a
money value by an integer value is performed with truncation of the fractional part towards zero. To get a rounded result, divide by a floating-point value, or cast the
money value to
numeric before dividing and back to
money afterwards. (The latter is preferable to avoid risking precision loss.) When a
money value is divided by another
money value, the result is
double precision (i.e., a pure number, not money); the currency units cancel each other out in the division.