Re: passing user defined data types to stored procedures

Does the driver support passing UDTs as arguments to stored procs?

Suppose I have a class Foo that implements SQLData.

On the server side, I've created a composite type called "foo", along with a
proc that accepts a single "foo" argument and returns a "foo".

On the client side, I acquire a connection and set its type map such that
"foo" maps to Foo.class.

When I try to setObject(2, new Foo()) on a CallableStatement, I get that the
driver can't infer the SQL type to use for an instance of class Foo.

Have I screwed something up, or is this just not supported? The driver docs
didn't have much to say, that I could find.

On Fri, 14 Nov 2008, Jay Howard wrote:

> Does the driver support passing UDTs as arguments to stored procs?
>

Sort of, but not in the standard fashion. SQLData is not
supported, but it is possible to do it using PGobject (a postgresql
specific extension). If you make your class Foo extend PGobject [1] and
make getType return the type name and getValue return the text
representation that the server expects it will work for sending data to
the server. To get objects of this type back from the server, you must
register them via PGConnection.addDataType [2].

Sample text representation of a complex type:

jurka=# create type mytype as (a int, b text, c date);
CREATE TYPE
jurka=# select '(3,"a,b",2008-11-20)'::mytype;
mytype
----------------------
(3,"a,b",2008-11-20)
(1 row)

Kris Jurka

[1] http://jdbc.postgresql.org/documentation/publicapi/org/postgresql/util/PGobject.html
[2] http://jdbc.postgresql.org/documentation/publicapi/org/postgresql/PGConnection.html#addDataType(java.lang.String,%20java.lang.Class)

Interesting. I did some experimenting with this last night, and it led to a
followup question:

Is it possible to return (and pass) arrays using java.sql.Array?

I wrote a test proc that returns an array of integers. I can retrieve it on
the java side as a Jdbc3Array, which implements java.sql.Array.

Unfortunately, getArray() (and its variants) seem not to have been
implemented yet by Jdbc3Array.

Any way to pass arrays back and forth? I could always have the proc return
a refcursor and handle it in Java as a ResultSet, but I was looking for a
convenient way to avoid that.

On Sat, Nov 15, 2008 at 11:25 AM, Kris Jurka <books(at)ejurka(dot)com> wrote:

>
>
> On Fri, 14 Nov 2008, Jay Howard wrote:
>
> Does the driver support passing UDTs as arguments to stored procs?
>>
>>
> Sort of, but not in the standard fashion. SQLData is not supported, but it
> is possible to do it using PGobject (a postgresql specific extension). If
> you make your class Foo extend PGobject [1] and make getType return the type
> name and getValue return the text representation that the server expects it
> will work for sending data to the server. To get objects of this type back
> from the server, you must register them via PGConnection.addDataType [2].
>
> Sample text representation of a complex type:
>
> jurka=# create type mytype as (a int, b text, c date);
> CREATE TYPE
> jurka=# select '(3,"a,b",2008-11-20)'::mytype;
> mytype
> ----------------------
> (3,"a,b",2008-11-20)
> (1 row)
>
> Kris Jurka
>
> [1]
> http://jdbc.postgresql.org/documentation/publicapi/org/postgresql/util/PGobject.html
> [2]
> http://jdbc.postgresql.org/documentation/publicapi/org/postgresql/PGConnection.html#addDataType(java.lang.String,%20java.lang.Class)<http://jdbc.postgresql.org/documentation/publicapi/org/postgresql/PGConnection.html#addDataType%28java.lang.String,%20java.lang.Class%29>
>

On Sat, 15 Nov 2008, Jay Howard wrote:

> Is it possible to return (and pass) arrays using java.sql.Array?
>
> I wrote a test proc that returns an array of integers. I can retrieve it on
> the java side as a Jdbc3Array, which implements java.sql.Array.
>
> Unfortunately, getArray() (and its variants) seem not to have been
> implemented yet by Jdbc3Array.
>

getArray is implemented and should work. Perhaps you're getting confused
because you're expecting to receive int[] and you're getting Integer[]
instead? It's tough to say what's going wrong without some example code.

Kris Jurka

Actually it may not have been an array of integers. I was doing stuff with
composite types, so that may be the problem. The message I got from
getArray() indicated that the "full" version of that method, which it must
call internally, wasn't implemented. I'll verify tonight and respond with
some sample code.

On Sat, Nov 15, 2008 at 12:02 PM, Kris Jurka <books(at)ejurka(dot)com> wrote:

>
>
> On Sat, 15 Nov 2008, Jay Howard wrote:
>
> Is it possible to return (and pass) arrays using java.sql.Array?
>>
>> I wrote a test proc that returns an array of integers. I can retrieve it
>> on
>> the java side as a Jdbc3Array, which implements java.sql.Array.
>>
>> Unfortunately, getArray() (and its variants) seem not to have been
>> implemented yet by Jdbc3Array.
>>
>>
> getArray is implemented and should work. Perhaps you're getting confused
> because you're expecting to receive int[] and you're getting Integer[]
> instead? It's tough to say what's going wrong without some example code.
>
> Kris Jurka
>

Turns out I was returning an array of composites after all. Everything
works as expected when the array elements are simple types.

That begs the question, though- is supporting arrays of composite types on
the list of "things to do"?

Here's what I get when I call java.sql.Array.getArray() and the array
contains composites:

Method org.postgresql.jdbc4.Jdbc4Array.getArrayImpl(long,int,Map) is not yet
implemented.

On Sat, Nov 15, 2008 at 12:20 PM, Jay Howard <jhoward(at)alumni(dot)utexas(dot)net>wrote:

> Actually it may not have been an array of integers. I was doing stuff with
> composite types, so that may be the problem. The message I got from
> getArray() indicated that the "full" version of that method, which it must
> call internally, wasn't implemented. I'll verify tonight and respond with
> some sample code.
>
>
> On Sat, Nov 15, 2008 at 12:02 PM, Kris Jurka <books(at)ejurka(dot)com> wrote:
>
>>
>>
>> On Sat, 15 Nov 2008, Jay Howard wrote:
>>
>> Is it possible to return (and pass) arrays using java.sql.Array?
>>>
>>> I wrote a test proc that returns an array of integers. I can retrieve it
>>> on
>>> the java side as a Jdbc3Array, which implements java.sql.Array.
>>>
>>> Unfortunately, getArray() (and its variants) seem not to have been
>>> implemented yet by Jdbc3Array.
>>>
>>>
>> getArray is implemented and should work. Perhaps you're getting confused
>> because you're expecting to receive int[] and you're getting Integer[]
>> instead? It's tough to say what's going wrong without some example code.
>>
>> Kris Jurka
>>
>
>

On Sat, 15 Nov 2008, Jay Howard wrote:

> Turns out I was returning an array of composites after all. Everything
> works as expected when the array elements are simple types.
>
> That begs the question, though- is supporting arrays of composite types on
> the list of "things to do"?

Sure. The problem here is our poor support of user defined types, not
specifically arrays of composite types.

Kris Jurka