Hi Albert,
As Dyre and Donald point out, the LIKE operator can only be applied to
strings. You can write your own casting function to turn your integers
into strings (or to extract other information which you may be encoding
in integers). Something like the following should work:
select * from t
where intToString( intCol ) like '34%'
Note that this kind of query fragment won't be optimizable. That is, the
optimizer won't be able to take advantage of useful indexes which you've
put on intCol.
Hope this helps,
-Rick
Albert Kam wrote:
Hello again Apache Derby,
I'm currently porting my little webapp from using mysql to apache derby.
One of the issue i'm having right now is the like clause being used
for non-string types.
I tried the ij, issuing simple sql statement like :
ij> select sc.id <http://sc.id> from sms_command sc where sc.id
<http://sc.id> like '%';
ERROR 42884: No authorized routine named 'LIKE' of type 'FUNCTION'
having compatible arguments was found.
But it works fine for the string type :
ij> select sc.id <http://sc.id>, sc.dbpool_name from sms_command sc
where sc.dbpool_name like 'd%';
ID |DBPOOL_NAME
---------------------------
6 |demo
14 |demo
21 |demo
23 |test
I tried describe the table, and here's the output :
ij> describe sms_command;
COLUMN_NAME
|TYPE_NAME|DEC&|NUM&|COLUM&|COLUMN_DEF|CHAR_OCTE&|IS_NULL&
------------------------------------------------------------------------------
ID |INTEGER |0 |10 |10
|NULL |NULL |NO
DBPOOL_NAME |VARCHAR |NULL|NULL|15 |NULL |30 |NO
....
I'm quite sure that there's no point in this case to use like-clause
for an integer typed column, but there are several cases that the like
clause can be useful for integer typed column, like when trying to
find out an records that contains such and such part of a number.
When using mysql, using like-clause on non-string types works in my
proggie prior to porting it to derby.
Anyway, is there a configuration that can be use to be 'friendly' for
using like-clause on non-string types ? Or perhaps anything else that
i'm missing out from the docs ? :)
Regards,
Albert Kam
--
Do not pursue the past. Do not lose yourself in the future.
The past no longer is. The future has not yet come.
Looking deeply at life as it is in the very here and now,
the practitioner dwells in stability and freedom.
(Thich Nhat Hanh)
