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.
2017-02-10 16:32 GMT-05:00 Adrian Klaver <adrian.kla...@aklaver.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
>
>
>
>> 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.kla...@aklaver.com
>
