You could probably create a before insert trigger which compares the number of fractional digits in the given number with the defined scale (surely some system table can offer you that) and raises an exception if needed. I do agree though with Niklas Johansson's remarks and wonder with him on what exactly you're trying to accomplish.
>>> "Horst Dehmer" <horst.dehmer@inode.at> 2008-02-15 8:28 >>>
Hi!
Is there an easy way to enforce strict handling of numeric values with scales, i.e. raise an exception/error instead of rounding values to the specified scale?
In a given schema with 250+ tables I have lots of numeric columns with a scale > 0. The docs (chapter 8.1.2) state clearly that greater scales are rounded: "If the scale of a value to be stored is greater than the declared scale of the column, the system will round the value to the specified number of fractional digits."
<p>
This works as designed:
<p>
<pre>
<code>
create table dummy (pi numeric(5,4));
insert into dummy values(3.141); -- insert #1
insert into dummy values(3.1415); -- insert #2
insert into dummy values(3.14159); -- insert #3
insert into dummy values('3.14159'); -- insert #4
postgres=# select * from dummy;
pi
--------
3.1410
3.1415
3.1416
3.1416
(4 rows)
</code>
</pre>
I wonder if there is a generic/transparent way (say a config parameter) to force postgresql to raise an error for inserts #3 and #4. If there is no easy way, what other alternatives exist? Sadly, changing the schema is hardly a possibility for me :-(
Any suggestions are appreciated!
Note: Using PostgreSQL 8.3 with JDBC.
-- Horst Dehmer