PostGreSql Tips 1

DATE FUNCTIONS IN POSTGRESQL


day

The day (of the month) field (1 - 31)

SELECT EXTRACT(DAY FROM TIMESTAMP '2001-02-16 20:38:40');
Result: 16

decade

The year field divided by 10

SELECT EXTRACT(DECADE FROM TIMESTAMP '2001-02-16 20:38:40');
Result: 200

dow

The day of the week (0 - 6; Sunday is 0) (for timestamp values only)

SELECT EXTRACT(DOW FROM TIMESTAMP '2001-02-16 20:38:40');
Result: 5

Note that extract's day of the week numbering is different from that of the to_char function.


doy

The day of the year (1 - 365/366) (for timestamp values only)

SELECT EXTRACT(DOY FROM TIMESTAMP '2001-02-16 20:38:40');
Result: 47