how to call a pg function with libpq and get the param value - c

ALL
I have a postgresql function,so this:
CREATE OR REPLACE FUNCTION query_callouts(
INOUT io_cursor_ref refcursor,
INOUT opstatus integer,
INOUT errtext character varying)
RETURNS record AS
$BODY$
DECLARE
BEGIN
OPEN $1 FOR
SELECT tablename FROM pg_tables limit 10;
--SELECT * from call_out_numbers;
RETURN;
Exception
When Others Then
GET STACKED DIAGNOSTICS opstatus = RETURNED_SQLSTATE,
errText = MESSAGE_TEXT;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION query_callouts(refcursor, integer, character varying)
OWNER TO postgres;
I want to known ,how to use libpq in my c codes to visit the function - query_callouts and get the param io_cursor_ref and opstatus and errtext?


You can call the function just like you are executing any query:
select * from query_callouts('mycur', 0, '');
io_cursor_ref | opstatus | errtext
---------------+----------+---------
mycur | 0 |
(1 row)
opstatus and errtext would be set to the appropriate values if an exception occurs.
io_cursor_ref contains the name you have passed to the function.
Internally, a refcursor value is simply the string name of a so-called
portal containing the active query for the cursor. This name can be
passed around, assigned to other refcursor variables, and so on,
without disturbing the portal.
Note, you can use a refcursor only within a transaction.
All portals are implicitly closed at transaction end. Therefore a
refcursor value is usable to reference an open cursor only until the
end of the transaction.
You can use explicit transaction:
begin;
select * from query_callouts('mycur', 0, '');
fetch all in mycur;
-- save or show the query result
-- and finally
commit;
or use mycur inside a function.
The quotes are from the documentation.


It's just like any other query.
SELECT * FROM query_callouts('cursorname', 4, 'msg')
I suspect some if not all of your parameters should be OUT parameters not INOUT parameters, though. You don't ever use the input value of errtext at least.

Related

How can I add defined parameter to (NEXT VALUE FOR) command?

CREATE OR ALTER FUNCTION sso.FINDSEQVALUE
(#sequence_text text)
RETURNS int
AS
BEGIN
DECLARE #value int;
DECLARE #sequence_value nvarchar(150);
SELECT #sequence_value = CAST(#sequence_text AS nvarchar(150));
SELECT #value = NEXT VALUE FOR #sequence_value;
RETURN #value;
END;
I have a problem. I have created a function on SQL Server and I defined the parameter as you can see. But I cannot add the this command #sequence_value after NEXT VALUE FOR command and I am getting an error.
Incorrect syntax near '#sequence_value'
Somebody can say that "You can use (SELECT NEXT VALUE FOR [SEQUENCE])". But I need this function because of there are two different database on my project. I need same function for databases. In addition function parameter need to be text.
What should I do?

How do I dynamically pass a role name to IS_ROLE_IN_SESSION?

I'm setting up a masking policy that can be bypassed if the user's current role inherits from a specified role. This can be easily done with the function IS_ROLE_IN_SESSION. The challenge is I want to be able to change the specified role without having to modify the masking policy.
These examples assume the user is using a role other than ACCOUNTADMIN.
I got it to work with a session variable, but this is not secure since I can't control access to session variables:
create or replace table tab as select * from values('personal value') d (data);
set unmask_role = 'PUBLIC';
alter table tab modify column data unset masking policy;
create or replace masking policy hide as (d varchar) returns varchar ->
iff(is_role_in_session($unmask_role),d,replace(d,'personal value','hidden'));
alter table tab modify column data set masking policy hide;
set unmask_role = 'PUBLIC';
select * from tab;
-- Works as expected: shows personal value
set unmask_role = 'ACCOUNTADMIN';
select * from tab;
-- Works as expected: shows hidden
Ideally I would provide the role in a table since I can control access to the contents of a table but I can't get past these errors:
create or replace table unmask_role_tab as select 'PUBLIC' role;
alter table tab modify column data unset masking policy;
create or replace masking policy hide as (d varchar) returns varchar ->
iff(is_role_in_session((select role from unmask_role_tab)),d,replace(d,'personal value','hidden'));
alter table tab modify column data set masking policy hide;
select * from tab;
-- Fails with error:
-- SQL compilation error: error line Check Arg at position 0 invalid argument for function [IS_ROLE_IN_SESSION] unexpected argument [(SELECT UNMASK_ROLE_TAB.ROLE AS "ROLE" FROM UNMASK_ROLE_TAB AS UNMASK_ROLE_TAB)] at position 0,
alter table tab modify column data unset masking policy;
create or replace masking policy hide as (d varchar) returns varchar ->
(select iff(is_role_in_session(role),d,replace(d,'personal value','hidden')) from unmask_role_tab);
alter table tab modify column data set masking policy hide;
select * from tab;
-- Fails with error:
-- SQL compilation error: error line Check Arg at position 0 invalid argument for function [IS_ROLE_IN_SESSION] unexpected argument [UNMASK_ROLE_TAB.ROLE] at position 0,

It is an interesting question as it boils down to how to pass a "non-static" value to function that requires string_literal
IS_ROLE_IN_SESSION
is_role_in_session( '<string_literal>' )
Using view instead of table(if new entries has to be added then view defintion has to be updated, without changing masking policy definition):
create or replace table tab as select * from values('personal value') d (data);
CREATE OR REPLACE VIEW unmask_role_view
AS
SELECT 1 AS col WHERE IS_ROLE_IN_SESSION('PUBLIC')
-- UNION SELECT 1 AS col WHERE IS_ROLE_IN_SESSION('...') -- more entries
;
create or replace masking policy hide as (d varchar) returns varchar ->
case when exists(SELECT 1 FROM unmask_role_view) then d
else replace(d,'personal value','hidden')
end;
alter table tab modify column data set masking policy hide;
select * from tab;
A solution that requires defining all roles that should have access to data. It has one advantage though the roles are listed explicitly. One of the drawbacks is maintenance of this table.
create or replace table tab as select * from values('personal value') d (data);
create or replace table unmask_role_tab as select 'PUBLIC' role;
-- here we compare against CURRENT_ROLE
-- so we need all roles that have access to masked data
create or replace masking policy hide as (d varchar) returns varchar ->
case when exists(SELECT 1 FROM unmask_role_tab u WHERE u.role = CURRENT_ROLE()) then d
else replace(d,'personal value','hidden')
end;
alter table tab modify column data set masking policy hide;
select * from tab;
CREATE MASKING POLICY
CREATE [ OR REPLACE ] MASKING POLICY [ IF NOT EXISTS ] <name> AS
(VAL <data_type>) RETURNS <data_type> -> <expression_ON_VAL>
You can use:
Conditional Expression Functions
Context Functions,
and UDFs to write the SQL expression.
Attempt 1: Standard call
SELECT IS_ROLE_IN_SESSION(u.role) FROM unmask_role_tab u;
-- SQL compilation error: error line Check Arg at position 0 invalid argument
-- for function [IS_ROLE_IN_SESSION] unexpected argument [U.ROLE] at position 0
SELECT IS_ROLE_IN_SESSION(u.role::STRING) FROM unmask_role_tab u;
-- SQL compilation error: error line Check Arg at position 0 invalid argument
-- for function [IS_ROLE_IN_SESSION] unexpected argument [U.ROLE] at position 0
Attempt 2: Create UDF(executiing build SQL is not available)
CREATE OR REPLACE FUNCTION role_check(role_name STRING)
RETURNS boolean
LANGUAGE JAVASCRIPT
AS
$$
var res = snowflake.createStatement({sqlText: 'SELECT IS_ROLE_IN_SESSION(:1)'
, binds:[ROLE_NAME]}).execute()
res.next();
return res.getColumnValue(1);
$$;
SELECT role_check(u.role) FROM unmask_role_tab u;
-- JavaScript execution error: Uncaught ReferenceError:
-- snowflake is not defined in ROLE_CHECK
Attempt 3 SQL UDF(same error like with direct call
CREATE OR REPLACE FUNCTION role_check(role_name STRING)
RETURNS BOOLEAN
LANGUAGE SQL
AS $$
IS_ROLE_IN_SESSION(ROLE_NAME)
$$;
SELECT *, role_check(role) FROM unmask_role_tab;
-- SQL compilation error: error line Check Arg at position 0 invalid argument
-- for function [IS_ROLE_IN_SESSION] unexpected argument [UNMASK_ROLE_TAB.ROLE]
Attempt 4 User-Defined stored procedure:
CREATE OR REPLACE PROCEDURE role_check_proc(role_name STRING)
RETURNS boolean
LANGUAGE JAVASCRIPT
AS
$$
var res = snowflake.createStatement({sqlText: 'SELECT IS_ROLE_IN_SESSION(:1)'
,binds:[ROLE_NAME]}).execute()
res.next();
return res.getColumnValue(1);
$$;
CALL role_check_proc((SELECT role FROM unmask_role_tab));
-- TRUE
-- Works only if table contains single entry
It returns result but stored procedure call cannot be used in masking policy/SQL query call.
Wrapping them with function will not work as it is not possible to call SP from function.
CREATE OR REPLACE FUNCTION role_check(role_name STRING)
RETURNS BOOLEAN
LANGUAGE SQL
AS $$
CALL role_check_proc(ROLE_NAME::STRING)
$$;

How to loop from an array received as a parameter in plpgsql function?

I'm kinda new into pgplsql and so far I have to create a function that loops an array that is received as a function.
The main idea of the function is to insert new records into a table that maps each id contained in the array received with a new formatted id, the format depends on the second parameter received and return the table "idsTable".
The problem is that when I try to create the function it sends me an error:
ERROR: loop variable of FOREACH must be a known variable or list of variables
LINE 38: FOREACH objectid IN ARRAY idsList LOOP
I'm not sure if I have to declare the objectid variable cause in the examples that I have seen they didn't.
So far I have this:
CREATE OR REPLACE FUNCTION createId(idsList varchar[], objectType varchar)
RETURNS TABLE(original_id varchar, new_id char) as
$$
BEGIN
IF LOWER(objectType) = 'global' THEN
FOREACH objectid IN ARRAY idsList LOOP
INSERT INTO idsTable(original_id, new_id)
VALUES(objectid, 'GID'||nextval('mapSquema.globalid')::TEXT);
END LOOP;
ELSE
FOREACH objectid IN ARRAY idsList LOOP
INSERT INTO idsTable(original_id, new_id)
VALUES(objectid, 'ORG'||nextval('mapSquema.globalid')::TEXT);
END LOOP;
END IF;
END;
$$ LANGUAGE plpgsql;
Any ideas of what could be wrong?
edit: I haven't add the part where the idsTable is returned.

Unrelated, but: you don't really need a loop for that. And you can simplify the function by only writing the INSERT once. You also forgot to return something from your function. As it is declared as returns table that is required:
CREATE OR REPLACE FUNCTION createid(idslist varchar[], objecttype varchar)
RETURNS TABLE(original_id varchar, new_id varchar) as
$$
declare
l_prefix text;
BEGIN
IF LOWER(objectType) = 'global' THEN
l_prefix := 'GID';
ELSE
l_prefix := 'ORG';
END IF;
RETURN QUERY --<< return the result of the insert
INSERT INTO idstable(original_id, new_id)
select t.x, l_prefix||nextval('mapSquema.globalid')::TEXT
from unnest(idslist) as t(x)
returning *
END;
$$ LANGUAGE plpgsql;

Passing Array to Oracle Function

I am passing an array to a PL/SQL package function. I am doing this to use this array in a query inside the function which has IN clause.
My declaration of package looks like :
create or replace
PACKAGE selected_pkg IS
TYPE NUM_ARRAY IS TABLE OF NUMBER;
FUNCTION get_selected_kml(
in_layer IN NUMBER,
in_id IN NUMBER,
in_feature_ids IN selected_pkg.NUM_ARRAY,
in_lx IN NUMBER,
in_ly IN NUMBER,
in_ux IN NUMBER,
in_uy IN NUMBER
)
RETURN CLOB;
END selected_pkg;
In my PL/SQL function I am firing a query like following
select a.id, a.geom from Table_FIELD a where a.id in (select * from table (in_feature_ids)) and sdo_filter(A.GEOM,mdsys.sdo_geometry(2003,4326,NULL,mdsys.sdo_elem_info_array(1,1003,3), mdsys.sdo_ordinate_array(0,57,2.8,59)),'querytype= window') ='TRUE'
The same query runs fine if I run it from anonymous block like
CREATE TYPE num_arr1 IS TABLE OF NUMBER;
declare
myarray num_arr1 := num_arr1(23466,13396,14596);
BEGIN
FOR i IN (select a.id, a.geom from Table_FIELD a where a.id in (select * from table (myarray)) and sdo_filter(A.GEOM,mdsys.sdo_geometry(2003,4326,NULL,mdsys.sdo_elem_info_array(1,1003,3), mdsys.sdo_ordinate_array(0,57,2.8,59)),'querytype= window') ='TRUE'
loop
dbms_output.put_line(i.id);
end loop;
end;
If I try to run it by calling function as below
--Running function from passing array for IDs
declare
result CLOB;
myarray selected_pkg.num_array := selected_pkg.num_array(23466,13396,14596);
begin
result:=SELECTED_PKG.get_selected_kml(3, 19, myarray, 0.0,57.0,2.8,59);
end;
I am getting error
ORA-00904: "IN_FEATURE_IDS": invalid identifier
Could someone please help me understand the cause of it?
Thanks,
Alan

You cannot query a type declared in plsql in a sql query, as the sql engine doesn't recognise it.
Your first example works because you have declared the type numarr1 in the database, whereas the type selected_pkg.num_array is declared in a package.
Good summary here

I can't quite recreate the error you're getting; the anonymous block doesn't refer to in_feature_ids, and the package ought to only report that if it doesn't recognise it on compilation rather than at runtime - unless you're using dynamic SQL. Without being able to see the function body I'm not sure how that's happening.
But you can't use a PL/SQL-defined type in an SQL statement. At some point the table(in_feature_ids) will error; I'm getting an ORA-21700 when I tried it, which is a new one for me, I'd expect ORA-22905. Whatever the error, you have to use a type defined at schema level, not within the package, so this will work (skipping the spatial stuff for brevity):
CREATE TYPE num_array IS TABLE OF NUMBER;
/
CREATE OR REPLACE PACKAGE selected_pkg IS
FUNCTION get_selected_kml(
in_layer IN NUMBER,
in_id IN NUMBER,
in_feature_ids IN NUM_ARRAY,
in_lx IN NUMBER,
in_ly IN NUMBER,
in_ux IN NUMBER,
in_uy IN NUMBER
) RETURN CLOB;
END selected_pkg;
/
CREATE OR REPLACE PACKAGE BODY selected_pkg IS
FUNCTION get_selected_kml(
in_layer IN NUMBER,
in_id IN NUMBER,
in_feature_ids IN NUM_ARRAY,
in_lx IN NUMBER,
in_ly IN NUMBER,
in_ux IN NUMBER,
in_uy IN NUMBER
) RETURN CLOB IS
BEGIN
FOR i IN (select * from table(in_feature_ids)) LOOP
DBMS_OUTPUT.PUT_LINE(i.column_value);
END LOOP;
RETURN null;
END get_selected_kml;
END selected_pkg;
/
... and calling that also using the schema-level type:
set serveroutput on
declare
result CLOB;
myarray num_array := num_array(23466,13396,14596);
begin
result:=SELECTED_PKG.get_selected_kml(3, 19, myarray, 0.0,57.0,2.8,59);
end;
/
23466
13396
14596
PL/SQL procedure successfully completed.
Also note that you have to use exactly the same type, not just one that looks the same, as discussed in a recent question. You wouldn't be able to call your function with a variable of num_arr1 type, for example; they look the same on the surface but to Oracle they are different and incompatible.

Returning array via INOUT parameter without modifications

I'm using PostgreSQL 9.1.3 and the following functions:
CREATE OR REPLACE FUNCTION cad(INOUT args text[], OUT retval int4) AS $cad$
BEGIN
retval := 0;
RAISE NOTICE 'cad: %', args;
END;
$cad$ LANGUAGE plpgsql;
CREATE OR REPLACE FUNCTION dodo(in_args text[]) RETURNS text[] AS $dodo$
DECLARE
_res text[];
_rv int4;
BEGIN
_res := in_args;
EXECUTE 'SELECT cad($1)' USING _res INTO _res, _rv;
RETURN _res;
END;
$dodo$ LANGUAGE plpgsql;
When I call cad directly, I get expected output:
psql$ select cad(ARRAY['Quiz']);
NOTICE: cad: {Quiz}
-[ RECORD 1 ]---
cad | ({Quiz},0)
Time: 0,319 ms
My expected result for the dodo(ARRAY['Quiz']) call is the input array without changes. But instead I receive the following error:
psql$ select dodo(ARRAY['Quiz']);
NOTICE: cad: {Quiz}CONTEXT: SQL statement "SELECT cad($1)"
PL/pgSQL function "dodo" line 8 at EXECUTE statement
ERROR: array value must start with "{" or dimension information
CONTEXT: PL/pgSQL function "dodo" line 8 at EXECUTE statement
What is wrong here?
P.S.: I have to use EXECUTE as function to call will vary, code simplified for the purpose of question.

You want something like:
EXECUTE 'SELECT * FROM cad($1)' USING _res INTO _res, _rv;
The return type isn't two columns of text[],int it's a record of (text[],int) which needs unwrapping.

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