[GENERAL] Fwd: Query parameter types not recognized

[Roberto Balarezo]

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;

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

Why is it inferring that the type is integer, when I send it as Date??

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!
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