Birt报告-未从Postgres RefCursor获取数据

Question

I have this:

POSTGRES

/*THE PARAMETER in_test_id IS ONLY A TEST!!*/
CREATE OR REPLACE FUNCTION public.test_birt(in_test_id bigint DEFAULT NULL::bigint)
  RETURNS refcursor AS
$BODY$
DECLARE
    query text;
    tcursor   refcursor = 'tcursor';
BEGIN
    query := 'SELECT * FROM MY_TABLE';

    OPEN tcursor FOR execute query;
    return tcursor;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

BIRT

DATASET --> MyDataset --> select * from test_birt(?::bigint)

Here the screenshots:

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I need that Birt shows the values of MY_TABLE !!. In this case, this table have one varchar field, with the values: TEST1 , TEST2 , TEST3 . The Birt Version is 3.2 and the postgres is 9.2 .

NOTE The unique solution that i found was create a datatype and change the return datatype from my function, something like this:

RETURNS SETOF my_type AS

But I need that Bird can read this RefCursor.

Answer 1

You miss a FETCH statement.

When you call a function, then cursor "tcursor" is created (and opened). But nobody try to read from it. And without explicit support in Birt is impossible to call function and fetch data from cursor. You can try a hack - that can work or not (depends on implementation in Birt) - use following commands as source for dataset:

SELECT test_birt(?::bigint); FETCH ALL FROM tcursor;

I found link that shows so Birt didn't support it 5 years ago.

On second hand. In 9.2 you don't need to define own types for returning tables. You can use a table types - when you can return all columns or you can define output columns via TABLE keywords:

 CREATE TABLE foo(a int, b int); -- automatically it defined type foo

 CREATE OR REPLACE FUNCTION read_from_foo_1(_a int)
 RETURNS SETOF foo AS $$
   SELECT * FROM foo WHERE foo.a = _a;
 $$ LANGUAGE SQL;

or

 CREATE OR REPLACE FUNCTION read_from_foo_2()
 RETURNS TABLE(a int, b int, c int) AS $$
   SELECT a, b, a + b FROM foo;
 $$ LANGUAGE SQL;