Re: [GENERAL] Fwd: Query parameter types not recognized

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

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.klaver@aklaver.com