ROUND_VAR ​

Round a number (up or down) to the nearest integer. Optionally, specify the number of decimal places for the rounding. This function is equivalent to ROUND, except that it allows the second argument to be a column name or an expression, while ROUND enforces the use of a constant.

ROUND_VAR(number [, places])

The return type of the ROUND_VAR function is the DECIMAL type of the first argument. For example:

ROUND_VAR(1.234, 1*2) returns 1.230

Examples ​

Determine the precision and scale of a given DECIMAL value by using the integer values found in the seasonid column of the season table:

premdb=# select round_var(1.111567, seasonid), seasonid from season;
 round_var | seasonid 
-----------+----------
  1.100000 |        1
  1.110000 |        2
  1.112000 |        3
  1.111600 |        4
  1.111570 |        5
  1.111567 |        6
  1.111567 |        7
  1.111567 |        8
  1.111567 |        9
...
(25 rows)

Note that the scale of the result is 6 decimal places, so the results for seasonid 6 and higher are the same.

Enabling ROUND_VAR Behavior for ROUND ​

If you commonly supply a variable number of decimal places to the ROUND function, the configuration parameter enable_alternative_round will instruct the query planner to automatically translate ROUND to ROUND_VAR without modifying the original SQL text.