Re: Fwd: Query parameter types not recognized

On 02/10/2017 02:14 PM, Roberto Balarezo wrote:
> Hmmm... I didn't know PostgreSQL had a facility for query logging and
> debugging of parameters to a logfile. Thought I had to execute a
> describe or something like that. Thanks, I'll try it to see what's
> happening!

Start here:

https://www.postgresql.org/docs/9.6/static/runtime-config-logging.html

Set up logging and then set :

log_statement = 'all'

This will generate a lot of logs so you will probably not want to keep
it that way.

A Python example:

In [6]: date.today()
Out[6]: datetime.date(2017, 2, 10)

In [7]: cur.execute('select %s', [date.today()])

From Postgres log;

aklaver-2017-02-10 14:35:42.842 PST-0LOG: statement: BEGIN
aklaver-2017-02-10 14:35:42.842 PST-0LOG: statement: select
'2017-02-10'::date

>
> 2017-02-10 16:57 GMT-05:00 Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>>:
>
> On 02/10/2017 01:51 PM, Roberto Balarezo wrote:
>
> Hi,
>
> The parameter defaultDueDate is a java.sql.Date object, an
> actual Date.
> When I run the query with the value in it, it works:
> ```sql
> db=> select COALESCE(duedate, date '2017-02-01' + 1) from
> invoices order
> by duedate desc;
> coalesce
> ---------------------
> 2017-02-02 00:00:00
> 2017-02-02 00:00:00
> 2016-11-14 00:00:00
> 2017-02-10 00:00:00
> 2017-02-02 00:00:00
> 2017-02-13 00:00:00
> 2017-02-02 00:00:00
> 2017-02-02 00:00:00
> ```
>
> But when I send it as a parameter, it ignores it and seems to
> think the
> expression is of type interger.
>
>
> Which would indicate to me that is what is being passed in the
> parameter. If I would guess, from information here:
>
> https://docs.oracle.com/javase/7/docs/api/java/sql/Date.html
> <https://docs.oracle.com/javase/7/docs/api/java/sql/Date.html>
>
> milliseconds since January 1, 1970 00:00:00.000 GMT.
>
> Turn on/up logging in Postgres and run a query with that
> java.sql.Date object. I am betting that what you will see in the
> logs is an integer.
>
>
>
> 2017-02-10 16:32 GMT-05:00 Adrian Klaver
> <adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
> <mailto:adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>>>:
>
>
> On 02/10/2017 07:17 AM, Roberto Balarezo wrote:
>
> Hi, I would like to know why this is happening and some
> advice
> if there
> is a way to solve this problem:
>
> I have a query like this:
>
> |select COALESCE(duedate, ? + 1) from invoices order by
> duedate desc
> limit 10; |
>
>
> What is the 1 in ? + 1 supposed to represent?
>
>
> where ? is a query parameter. I’m using JDBC to connect
> to the
> database,
> and sending parameters like this:
>
> |query.setDate(1, defaultDueDate); |
>
> Where defaultDueDate is a java.sql.Date object. However,
> when I
> try to
> execute the query, I get this error:
>
> |org.postgresql.util.PSQLException: ERROR: COALESCE
> types timestamp
> without time zone and integer cannot be matched |
>
>
> So what is the actual value of defaultDueDate?
>
> Looks like it is an integer from the ERROR message.
>
> Might want to look in the Postgres logs to see if they show
> anything
> that might help.
>
>
> Why is it inferring that the type is integer, when I
> send it as
> Date??
>
>
> I don't use Java, but I did find the below, don't know if it
> helps?:
>
>
> https://jdbc.postgresql.org/documentation/94/escapes-datetime.html
> <https://jdbc.postgresql.org/documentation/94/escapes-datetime.html>
>
> <https://jdbc.postgresql.org/documentation/94/escapes-datetime.html
> <https://jdbc.postgresql.org/documentation/94/escapes-datetime.html>>
>
>
>
> When I force the type using a cast, like this:
>
> |select COALESCE(duedate, CAST(? AS DATE) + 1) from invoices
> order by
> duedate desc limit 10; |
>
> I get this error:
>
> |org.postgresql.util.PSQLException: ERROR: could not
> determine
> data type
> of parameter $1 |
>
> If I’m telling PostgreSQL that the parameter is going to
> be a
> Date, and
> send through the driver a Date, why it is having trouble
> determining the
> datatype of the parameter??
> What can I do to make it work?
>
> For reference, I’m using PostgreSQL 9.2.15 and JDBC driver
> 9.4.1207.jre6.
>
> Thanks for your advice!
>
> ​
>
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
> <mailto:adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>>
>
>
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com