Oracle Trunc Function

Menol — Mon, 24 Nov 2008 18:03:11 +0000

2008-11-24

Among various helpful functions provided by Oracle, Trunc function took my attention today because I had to fix a defect where some one has misunderstood and misused this function.

As the name itself suggests, the trunc function is capable of truncating a value. This function can be used either on a date type value or a numeric value.

Using trunc for numeric values

When it comes to numbers, trunc function can return a number truncated to a certain number of decimal places.

syntax:

trunc( number, [ decimal_places ] )

Example usage:

trunc(125.815)	would return 125
trunc(125.815, 0)	would return 125
trunc(125.815, 1)	would return 125.8
trunc(125.815, 2)	would return 125.81
trunc(125.815, 3)	would return 125.815
trunc(-125.815, 2)	would return -125.81
trunc(125.815, -1)	would return 120
trunc(125.815, -2)	would return 100
trunc(125.815, -3)	would return 0

Menol

Note: The trunc function does not round the values like in round function. It simply truncates the number as instructed.

Using trunc for date values

The trunc function is capable to truncate a date value to a specific unit of measure.

Syntax:

trunc ( date, [ format ] )

Possible values for format parameter:

Unit	Valid format parameters
Year	SYYYY, YYYY, YEAR, SYEAR, YYY, YY, Y
ISO Year	IYYY, IY, I
Quarter	Q
Month	MONTH, MON, MM, RM
Week	WW
IW	IW
W	W
Day	DDD, DD, J
Start day of the week	DAY, DY, D
Hour	HH, HH12, HH24
Minute	MI

Menol

Example Usage:

trunc(to_date(’22-AUG-03′), ‘YEAR’)	would return ’01-JAN-03′
trunc(to_date(’22-AUG-03′), ‘Q’)	would return ’01-JUL-03′
trunc(to_date(’22-AUG-03′), ‘MONTH’)	would return ’01-AUG-03′
trunc(to_date(’22-AUG-03′), ‘DDD’)	would return ’22-AUG-03′
trunc(to_date(’22-AUG-03′), ‘DAY’)	would return ’17-AUG-03′

Menol

Was this post helpful to you? How can I improve? – Your comment is highly appreciated!

Cassian Menol Razeek

I Learnt Today... » Oracle

Oracle Trunc Function