My Question is "How can we return multiple records from pl/sql stored procedure without taking OUT parameter".I got this doubt because if we are using cursors or refcursor in out parameter it may degrade performance.So what is the solution??
As OldProgrammer wrote, i think the performance of a cursor wouldn't be you problem. But here a Solution anyway:
You can return custom types like Table of number. If it's only a list of numbers you could return a table of numbers. If you Want to return rows from a table you could return table of 'tablename'%ROWTYPE. But i guess you want to create some custom types.
CREATE OR REPLACE TYPE PUWB_INT.MyOrderType AS OBJECT
(
OrderId NUMBER,
OrderName VARCHAR2 (255)
)
/
CREATE OR REPLACE TYPE PUWB_INT.MyOrderListType AS TABLE OF MYORDERtype
/
Now we can use them similar to a return myNumberVariable;
Let's build a function (procedures don't have return values):
CREATE OR REPLACE FUNCTION PUWB_INT.MyFunction (SomeInput VARCHAR2)
RETURN MyOrderListType
IS
myOrderList MyOrderListType := MyOrderListType ();
BEGIN
FOR o IN (SELECT 1 AS Id, 'One' AS Name FROM DUAL
UNION ALL
SELECT 2 AS Id, 'Two' AS Name FROM DUAL)
LOOP
myOrderList.EXTEND ();
myOrderList (myOrderList.COUNT) := MyOrderType (o.Id, o.Name || '(' || SomeInput || ')');
END LOOP;
RETURN myOrderList;
END MyFunction;
/
Now we can call the function and get a table of our custom-type:
DECLARE
myOrderList MyOrderListType;
myOrder MyOrderType;
BEGIN
myOrderList := MyFunction ('test');
FOR o IN myOrderList.FIRST .. myOrderList.LAST
LOOP
myOrder := myOrderList (o);
DBMS_OUTPUT.put_line ('Id: ' || myOrder.OrderId || ', Name: ' || myOrder.OrderName);
END LOOP;
END;
Be aware, that the calling schema, has to know the type.
Related
I want to loop thru all the records and concatenate them into one string.
Here is the code:
create or replace PROCEDURE P_GET_TRACKING_NOS
(
P_ORDERID NUMBER,
TRACKINGNOS OUT VARCHAR2
)
IS
CURSOR C1 IS
SELECT TRACKID
FROM MULTISHIPDTL
WHERE ORDERID = P_ORDERID;
BEGIN
TRACKINGNOS := '';
FOR TRACKID_REC IN C1
LOOP
TRACKINGNOS := TRACKINGNOS + ', ' + TRACKID_REC.TRACKID;
END LOOP;
END;
Depending on how long the result is, and if it is shorter than 4000 characters, a simpler option would be to use LISTAGG, e.g.
select listagg(m.trackid, ', ') within group (order by null) result
from multishipdtl m
where m.orderid = p_orderid;
Besides, why is it a procedure? A function seems to be a better option (you can use it in SQL; a procedure with an OUT parameter requires a(n anonymous) PL/SQL block, declaring a variable which accepts the result). For example:
create or replace function f_get_tracking_nos (p_orderid in number)
return varchar2
is
retval varchar2(4000);
begin
select listagg(m.trackid, ', ') within group (order by null)
into retval
from multishipdtl m
where m.orderid = p_orderid;
return retval;
end;
I have a procedure in Oracle that I need to convert to Postgresql and need help on it. It paases a collection of objects in a procedure.The procedure then checks if each object is present in a database table or not and if present it gives a message that , that specific element is found/present. if some element that is paassed to the procedure is not present in the table, the procedure just doesnt do anything. I have to write equivalent of that in postgresql. I think the heart of the issue is this statement:
SELECT COUNT (*)
INTO v_cnt
FROM **TABLE (p_cust_tab_type_i)** pt
WHERE pt.ssn = cc.ssn;
In Oracle a collection can be treated as a table and one can query it but I dont know how to do that in postgresql. The code to create the table, add data, create the procedure, call the procedure by passing the collection (3 objects) and output of that is posted below. Can someone suggest how this can be done in postgresql?
Following the oracle related code and details:
--create table
create table temp_n_tab1
(ssn number,
fname varchar2(20),
lname varchar2(20),
items varchar2(100));
/
--add data
insert into temp_n_tab1 values (1,'f1','l1','i1');
--SKIP no. ssn no. 2 intentionally..
insert into temp_n_tab1 values (3,'f3','l3','i3');
insert into temp_n_tab1 values (4,'f4','l4','i4');
insert into temp_n_tab1 values (5,'f5','l5','i5');
insert into temp_n_tab1 values (6,'f6','l6','i6');
commit;
--create procedure
SET SERVEROUTPUT ON
CREATE OR REPLACE PROCEDURE temp_n_proc (
p_cust_tab_type_i IN temp_n_customer_tab_type)
IS
t_cust_tab_type_i temp_n_customer_tab_type;
v_cnt NUMBER;
v_ssn temp_n_tab1.ssn%TYPE;
CURSOR c
IS
SELECT ssn
FROM temp_n_tab1
ORDER BY 1;
BEGIN
--t_cust_tab_type_i := p_cust_tab_type_i();
FOR cc IN c
LOOP
SELECT COUNT (*)
INTO v_cnt
FROM TABLE (p_cust_tab_type_i) pt
WHERE pt.ssn = cc.ssn;
IF (v_cnt > 0)
THEN
DBMS_OUTPUT.put_line (
'The array element '
|| TO_CHAR (cc.ssn)
|| ' exists in the table.');
END IF;
END LOOP;
EXCEPTION
WHEN OTHERS
THEN
DBMS_OUTPUT.PUT_LINE (SQLERRM);
END;
/
--caller proc
SET SERVEROUTPUT ON
declare
array temp_n_customer_tab_type := temp_n_customer_tab_type();
begin
for i in 1 .. 3
loop
array.extend;
array(i) := temp_n_cust_header_type( i, 'name ' || i, 'lname ' || i,i*i*i*i );
end loop;
temp_n_proc( array );
end;
/
caller proc output:
The array element 1 exists in the table.
The array element 3 exists in the table.
When you create a table in Postgres, a type with the same name is also created. So you can simply pass an array of the table's type as a parameter to the function.
Inside the function you can then use unnest() to treat the array like a table.
The following is the closest match to your original Oracle code:
create function temp_n_proc(p_cust_tab_type_i temp_n_tab1[])
returns void
as
$$
declare
l_rec record;
l_msg text;
l_count integer;
BEGIN
for l_rec in select t1.ssn
from temp_n_tab1 t1
loop
select count(*)
into l_count
from unnest(p_cust_tab_type_i) as t
where t.ssn = l_rec.ssn;
if l_count > 0 then
raise notice 'The array element % exist in the table', l_rec.ssn;
end if;
end loop;
END;
$$
language plpgsql;
The row-by-row processing is not a good idea to begin with (neither in Postgres, nor in Oracle). It would be a lot more efficient to get the existing elements in a single query:
create function temp_n_proc(p_cust_tab_type_i temp_n_tab1[])
returns void
as
$$
declare
l_rec record;
l_msg text;
BEGIN
for l_rec in select t1.ssn
from temp_n_tab1 t1
where t1.ssn in (select t.ssn
from unnest(p_cust_tab_type_i) as t)
loop
raise notice 'The array element % exist in the table', l_rec.ssn;
end loop;
return;
END;
$$
language plpgsql;
You can call the function like this:
select temp_n_proc(array[row(1,'f1','l1','i1'),
row(2,'f2','l2','i2'),
row(3,'f3','l3','i3')
]::temp_n_tab1[]);
However a more "Postgres" like and much more efficient way would be to not use PL/pgSQL for this, but create a simple SQL function that returns the messages as a result:
create or replace function temp_n_proc(p_cust_tab_type_i temp_n_tab1[])
returns table(message text)
as
$$
select format('The array element %s exist in the table', t1.ssn)
from temp_n_tab1 t1
where t1.ssn in (select t.ssn
from unnest(p_cust_tab_type_i) as t)
$$
language sql;
This returns the output of the function as a result rather than using the clumsy raise notice.
You can use it like this:
select *
from temp_n_proc(array[row(1,'f1','l1','i1'),
row(2,'f2','l2','i2'),
row(3,'f3','l3','i3')
]::temp_n_tab1[]);
I have a package which declares a collection of type table of some database table's %rowtype. It also declares a function to populate the package-level variable with some data. I can now print the data with dbms_output, seems fine.
But when I use the package-level variable in some sql I get the following error:
ORA-21700: object does not exist or is marked for delete
ORA-06512: at "TESTDB.SESSIONGLOBALS", line 17
ORA-06512: at line 5
Here is my code:
create some dummy data:
drop table "TESTDATA";
/
CREATE TABLE "TESTDATA"
( "ID" NUMBER NOT NULL ENABLE,
"NAME" VARCHAR2(20 BYTE),
"STATUS" VARCHAR2(20 BYTE)
);
/
insert into "TESTDATA" (id, name, status) values (1, 'Hans Wurst', 'J');
insert into "TESTDATA" (id, name, status) values (2, 'Hans-Werner', 'N');
insert into "TESTDATA" (id, name, status) values (3, 'Hildegard v. Bingen', 'J');
/
now create the package:
CREATE OR REPLACE
PACKAGE SESSIONGLOBALS AS
type t_testdata is table of testdata%rowtype;
v_data t_testdata := t_testdata();
function load_testdata return t_testdata;
END SESSIONGLOBALS;
and the package body:
CREATE OR REPLACE
PACKAGE BODY SESSIONGLOBALS AS
function load_testdata return t_testdata AS
v_sql varchar2(500);
BEGIN
if SESSIONGLOBALS.v_data.count = 0
then
v_sql := 'select * from testdata';
execute immediate v_sql
bulk collect into SESSIONGLOBALS.v_data;
dbms_output.put_line('data count:');
dbms_output.put_line(SESSIONGLOBALS.v_data.count);
end if; -- SESSIONGLOBALS.v_data.count = 0
-- ******************************
-- this line throws the error
insert into testdata select * from table(SESSIONGLOBALS.v_data);
-- ******************************
return SESSIONGLOBALS.v_data;
END load_testdata;
END SESSIONGLOBALS;
execute the sample:
DECLARE
v_Return SESSIONGLOBALS.T_TESTDATA;
BEGIN
v_Return := SESSIONGLOBALS.LOAD_TESTDATA();
dbms_output.put_line('data count (direct access):');
dbms_output.put_line(SESSIONGLOBALS.v_data.count);
dbms_output.put_line('data count (return value of function):');
dbms_output.put_line(v_Return.count);
END;
If the line marked above is commented out i get the expected result.
So can anyone tell me why the exception stated above occurs?
BTW: it is absolutely nessecary for me to execute the statement which populates the collection with data as dynamic sql because the tablename is not known at compiletime. (v_sql := 'select * from testdata';)
the solution is to use pipelined functions in the package
see: http://docs.oracle.com/cd/B19306_01/appdev.102/b14289/dcitblfns.htm#CHDJEGHC ( => section Pipelining Between PL/SQL Table Functions does the trick).
my package looks like this now (please take the table script from my question):
create or replace
PACKAGE SESSIONGLOBALS AS
v_force_refresh boolean;
function set_force_refresh return boolean;
type t_testdata is table of testdata%rowtype;
v_data t_testdata;
function load_testdata return t_testdata;
function get_testdata return t_testdata pipelined;
END SESSIONGLOBALS;
/
create or replace
PACKAGE BODY SESSIONGLOBALS AS
function set_force_refresh return boolean as
begin
SESSIONGLOBALS.v_force_refresh := true;
return true;
end set_force_refresh;
function load_testdata return t_testdata AS
v_sql varchar2(500);
v_i number(10);
BEGIN
if SESSIONGLOBALS.v_data is null then
SESSIONGLOBALS.v_data := SESSIONGLOBALS.t_testdata();
end if;
if SESSIONGLOBALS.v_force_refresh = true then
SESSIONGLOBALS.v_data.delete;
end if;
if SESSIONGLOBALS.v_data.count = 0
then
v_sql := 'select * from testdata';
execute immediate v_sql
bulk collect into SESSIONGLOBALS.v_data;
end if; -- SESSIONGLOBALS.v_data.count = 0
return SESSIONGLOBALS.v_data;
END load_testdata;
function get_testdata return t_testdata pipelined AS
v_local_data SESSIONGLOBALS.t_testdata := SESSIONGLOBALS.load_testdata();
begin
if v_local_data.count > 0 then
for i in v_local_data.first .. v_local_data.last
loop
pipe row(v_local_data(i));
end loop;
end if;
end get_testdata;
END SESSIONGLOBALS;
/
now i can do a select in sql like this:
select * from table(SESSIONGLOBALS.get_testdata());
and my data collection is only populated once.
nevertheless it is quite not comparable with a simple
select * from testdata;
from a performace point of view but i'll try out this concept for some more complicated use cases. the goal is to avoid doing some really huge select statements involving lots of tables distributed among several schemas (english plural for schema...?).
The syntax you use does not work:
insert into testdata select * from table(SESSIONGLOBALS.v_data); -- does not work
You have to use something like that:
forall i in 1..v_data.count
INSERT INTO testdata VALUES (SESSIONGLOBALS.v_data(i).id,
SESSIONGLOBALS.v_data(i).name,
SESSIONGLOBALS.v_data(i).status);
(which actually duplicates the rows in the table)
Package-level types cannot be used in SQL. Even if your SQL is called from within a package, it still can't see that package's types.
I'm not sure how you got that error message, when I compiled the package I got this error, which gives a good hint at the problem:
PLS-00642: local collection types not allowed in SQL statements
To fix this problem, create a type and a nested table of that type:
create or replace type t_testdata_rec is object
(
"ID" NUMBER,
"NAME" VARCHAR2(20 BYTE),
"STATUS" VARCHAR2(20 BYTE)
);
create or replace type t_testdata as table of t_testdata_rec;
/
The dynamic SQL to populate the package variable gets more complicated:
execute immediate
'select cast(collect(t_testdata_rec(id, name, status)) as t_testdata)
from testdata ' into SESSIONGLOBALS.v_data;
But now the insert will work as-is.
I need to return the names of employees in string format for all those employees whose manager ID depends on the passed parameter. When I compile the function I get an error. Here is the function code:
create or replace function Employee(v_manid IN employees.manager_id%type)
return varchar2
AS
cursor cur_emp is select last_name from employees where manager_id = v_manid;
v_names varchar2(10);
begin
for emp_rec in cur_emp
loop
v_name = v_name || emp_rec.last_name ||', ';
end loop;
return v_name
end;
/
The error is:
Error(8,8): PLS-00103: Encountered the symbol "=" when expecting one
of the following: := . ( # % ; Error(8,44): PLS-00103:
Encountered the symbol ";" when expecting one of the following: )
, * & - + / at mod remainder rem and or ||
Could anyone help me with this?
As stated in the other answers the reason why your function won't compile is threefold.
You've declared the variable v_names and are referencing it as v_name.
The assignment operator in PL/SQL is :=, you're using the equality operator =.
You're missing a semi-colon in your return statement; it should be return v_name;
It won't stop the function from compiling but the variable v_names is declared as a varchar2(10). It's highly unlikely that when a manager with multiple subordinates all their last names will fit into this. You should probably declare this variable with the maximum size; just in case.
I would like to add that you're doing this a highly inefficient way. If you were to do the string aggregation in SQL as opposed to a PL/SQL loop it would be better. From 11g release 2 you have the listagg() function; if you're using a version prior to that there are plenty of other string aggregation techniques to achieve the same result.
create or replace function employee ( p_manid in employees.manager_id%type
) return varchar2 is
v_names varchar2(32767); -- Maximum size, just in case
begin
select listagg(lastname, ', ') within group ( order by lastname )
into v_names
from employees
where manager_id = p_manid;
return v_names;
exception when no_data_found then
return null;
end;
/
Please note a few other changes I've made:
Prepend a different letter onto the function parameter than the variable to make it clear which is which.
Add in some exception handling to deal with there being no data for that particular manager.
You would have returned , if you had no data I return NULL. If you want to return a comma instead simply put this inside the exception.
Rather than bother to create a cursor and loop through it etc I let Oracle do the heavy lifting.
It's rather curious that you would want to return a comma delimited list as there is little that you would be able to do with it in Oracle afterwards. It might be more normal to return something like an array or an open cursor containing all the surnames. I assume, in this answer, that you have a good reason for doing what you are.
There are a couple of things to be noted.
Declared as v_names but used as v_name
Assignemnt should be like v_name := v_name || emp_rec.last_name ||
', ';
v_name is declared with size of 10, it would be too small and would
give an error when you execute, so you could declare as
v_name employees.last_name%TYPE;
You could create your function as
CREATE OR REPLACE FUNCTION employee (v_manid IN employees.manager_id%TYPE)
RETURN VARCHAR2
AS
v_name employees.last_name%TYPE;
CURSOR cur_emp
IS
SELECT last_name
FROM employees
WHERE manager_id = v_manid;
BEGIN
FOR emp_rec IN cur_emp
LOOP
v_name := v_name || emp_rec.last_name || ', ';
END LOOP;
RETURN v_name;
END;
/
I guess you should use := instead of =
like
v_name := v_name || emp_rec.last_name ||', ';
one more thing you also need to add semicolon ; at the end of return v_name like
return v_name;
I have to write an Oracle procedure which should invoke an Oracle function returning REF_CURSOR. The function is declared like that
FUNCTION "IMPACTNET"."TF_CONVERTPARA" (PARASTRING IN NVARCHAR2) RETURN SYS_REFCURSOR
AS
c SYS_REFCURSOR;
BEGIN
OPEN c FOR
SELECT SUBSTR(element, 1, INSTR(element, '|') - 1) as key,
SUBSTR(element, INSTR(element, '|') + 1, 99999) as val
FROM (
SELECT REGEXP_SUBSTR(PARASTRING, '[^;]+', 1, LEVEL) element
FROM dual
CONNECT BY LEVEL < LENGTH(REGEXP_REPLACE(PARASTRING, '[^;]+')) + 1
);
RETURN c;
END;
Can you tell me what I need to write in order to invoke the function from within my procedure? I'd like to insert all the returned values (shaped a table with two columns) into a rational table.
Thank you in advance!
Something along the lines of this should work (obviously, I'm guessing about table names and column names and the exact logic that you're trying to implement)
CREATE PROCEDURE some_procedure_name
AS
l_rc SYS_REFCURSOR := impactnet.tf_convertpara( <<some string>> );
l_key VARCHAR2(100);
l_val VARCHAR2(100);
BEGIN
LOOP
FETCH l_rc
INTO l_key, l_val;
EXIT WHEN l_rc%notfound;
INSERT INTO some_table( key_column, val_column )
VALUES( l_key, l_val );
END LOOP;
END;
As Ollie points out, it would be more efficient to do a BULK COLLECT and a FORALL. If you're just dealing with a few thousand rows (since your function is just parsing the data in a delimited string, I'm assuming you expect relatively few rows to be returned), the performance difference is probably minimal. But if you're processing more data, the difference can be quite noticeable. Depending on the Oracle version and your specific requirements, you may be able to simplify the INSERT statement in the FORALL to insert a record rather than listing each column from the record individually.
CREATE PROCEDURE some_procedure_name
AS
TYPE key_val_rec
IS RECORD(
key VARCHAR2(100),
val VARCHAR2(100)
);
TYPE key_val_coll
IS TABLE OF key_val_rec;
l_rc SYS_REFCURSOR := impactnet.tf_convertpara( <<some string>> );
l_coll key_val_coll;
BEGIN
LOOP
FETCH l_rc
BULK COLLECT INTO l_coll
LIMIT 100;
EXIT WHEN l_coll.count = 0;
FORALL i IN l_coll.FIRST .. l_coll.LAST
INSERT INTO some_table( key_column, val_column )
VALUES( l_coll(i).key, l_coll(i).val );
END LOOP;
END;