I have a stored procedure that starts with the following:
CREATE PROCEDURE somename.tablename (IN P_DATE DATE,
OUT P_ROWS_TO_INSERT INTEGER)
Can someone please explain the purpose of the IN and OUT parameter calls?
So SQL OUT parameter allows the stored procedure to the pass data value back to invoker. IN param is param what you adding to your stored procedure.
Basic example:
DECLARE
V_OUT INTEGER;
BEGIN
EXECUTE SomeName('22.2.2000', V_OUT);
DBMS_OUTPUT.PUT_LINE('OUT is: ' || V_OUT);
END;
Related
I am using SQLDEVELOPER TO make a stored procedure. this is my procedure
create or replace PROCEDURE SPP
(
inpt IN VARCHAR2,
opt OUT VARCHAR2
)
AS
BEGIN
SELECT U_ID
INTO opt
FROM TABLE_NAME
WHERE U_ID=inpt;
END;
so it should return the value in opt which i can then print or whatever.
i dont know how to execute it i tried running this script
var opt VARCHAR2;
exec SPP('test_user') := opt
but it doesnt work this is my first time doing stored procs and I'm really confused any help is appreciated
how do i make it run? i can make a stored proc run with input variables but with an output variable i mess up and I cant do it without using the SELECT (item) INTO format.
In order to call the procedure, you'd need to pass in a variable that the procedure can populate. Something like
DECLARE
l_output table_name.u_id%type;
BEGIN
spp( 'test_user', l_output );
END;
Now, that being said, declaring a stored procedure whose only purpose is to query the database and return a value is generally the wrong architectural choice. That's why functions exist.
CREATE OR REPLACE FUNCTION some_function( p_input IN table_name.u_id%type )
RETURN table_name.u_id%type
IS
l_uid table_name.u_id%type;
BEGIN
SELECT u_id
INTO l_uid
FROM table_name
WHERE u_id = p_input;
RETURN l_uid;
END;
which you can then call either in a PL/SQL block
DECLARE
l_output table_name.u_id%type;
BEGIN
l_output := some_function( 'test_user' );
END;
or in a SQL statement
SELECT some_function( 'test_user' )
FROM dual;
my procedure looks like this:
create or replace procedure odcitaj_surovinu_zo_skladu
(
v_id_suroviny IN surovina.id_suroviny%TYPE,
odcitaj IN OUT number
)
as
begin
...//some code here
odcitaj:=odcitaj-22;
...//some code here
end;
Procedure compiled w/o errors. I'm trying to execute it as:
execute odcitaj_surovinu_zo_skladu(1,200);
But it gives error, that '200' can't be used as target of assigment.
So how to execute it? Does ODCITAJ even need to be IN OUT? Cause i know that, if it was just IN , then it would act as constant and i won't be able to assign it anything
As Dmitry Bychenko said, you have to use a variable as the target of an OUT or IN OUT parameter, you can't provide a constant. Your parameter does need to be IN OUT since you're modifying it in the procedure. You can either use an anonymous block:
declare
l_odcitaj number;
begin
l_odcitaj := 200;
odcitaj_surovinu_zo_skladu(1, l_odcitaj);
-- do something with the updated value of l_odcitaj
end;
/
If you want to use the SQL*Plus/SQL Developer execute shorthand wrapper for an anonymous block you can declare a bind variable instead:
variable l_odcitaj number;
exec :l_odcitaj := 200;
exec odcitaj_surovinu_zo_skladu(1, :l_odcitaj);
Notice that the variable name has a colon in front when it is set and when the procedure is called, because it is a bind variable.
If you want you can then use that updated bind variable in other calls, or print it's post-procedure value:
print l_odcitaj
If the updated value - from odcitaj:=odcitaj-22; - doesn't need to be returned and is only used inside the procedure, you could declare the argument as IN and have a local variable which you set from the argument and then manipulate and use in the procedure.
create or replace procedure odcitaj_surovinu_zo_skladu
(
v_id_suroviny IN surovina.id_suroviny%TYPE,
v_odcitaj IN number
)
as
l_odcitaj number;
begin
l_odcitaj := v_odcitaj;
...//some code here
l_odcitaj:=l_odcitaj-22;
...//some code here
end;
/
You could then call the procedure with constant values. It just depends whether the caller needs to know the modified value.
I have a query and i have to put it in a stored procedure but when I call the stored procedure it doesn´t return anything;
This is my query:
select * from mdc_cat_parametros where param_llave='SMTP_SERVER';
When I execute the query it returns one row but the stored procedure doesn´t.
This is my stored procedure:
CREATE OR REPLACE PROCEDURE MDC_UTIL_PROCEDURE
AS
RT MDC_CAT_PARAMETROS%ROWTYPE;
BEGIN
SELECT * INTO RT FROM MDC_CAT_PARAMETROS WHERE PARAM_LLAVE='SMTP_SERVER';
END MDC_UTIL_PROCEDURE;
I call the stored procedure:
EXECUTE MDC_UTIL_PROCEDURE;
The stored procedure is populating RT but you then need to select out of it:
CREATE OR REPLACE PROCEDURE MDC_UTIL_PROCEDURE (results OUT SYS_REFCURSOR)
AS
RT MDC_CAT_PARAMETROS%ROWTYPE;
BEGIN
SELECT * INTO RT FROM MDC_CAT_PARAMETROS WHERE PARAM_LLAVE='SMTP_SERVER';
OPEN results FOR SELECT * FROM RT;
END MDC_UTIL_PROCEDURE;
or you could simplify it to get rid of the RT variable:
CREATE OR REPLACE PROCEDURE MDC_UTIL_PROCEDURE (results OUT SYS_REFCURSOR)
AS
BEGIN
OPEN results FOR
SELECT * FROM MDC_CAT_PARAMETROS WHERE PARAM_LLAVE='SMTP_SERVER';
END MDC_UTIL_PROCEDURE;
Your procedure is just fetching the result set into a local variable in the procedure. When the procedure exits, the variable is no longer in scope. If you want to return data from a select, you need to use a ref cursor. Here is a link to some good examples
Is there any way of calling a stored procedure from another stored procedure, and use retrieved value (from the second procedure) back in the first one?
-- procedure #1
create or replace procedure Proc1(p_RetValue out SomeDataType)
is
begin
-- any logic goes here
p_retValue := 5+5; -- for example. Let's assume that the SomeDataType is number;
end;
-- second procedure
create or replace procedure Proc2 is
l_variable number;
begin
Proc1(l_variable); -- the value 10 will be assigned to l_variable;
end;
I am trying to build an Oracle stored procedure which will accept a table name as a parameter. The procedure will then rebuild all indexes on the table.
My problem is I get an error while using the ALTER command from a stored procedure, as if PLSQL does not allow that command.
Use the execute immediate statement to execute DDL inside PL/SQL.
create procedure RebuildIndex(index_name varchar2) as
begin
execute immediate 'alter index ' || index_name || ' rebuild';
end;
I tested this code; it works.
Documentation.
Passing Schema Object Names As Parameters
Suppose you need a procedure that
accepts the name of any database
table, then drops that table from your
schema. You must build a string with a
statement that includes the object
names, then use EXECUTE IMMEDIATE to
execute the statement:
CREATE TABLE employees_temp AS SELECT last_name FROM employees;
CREATE PROCEDURE drop_table (table_name IN VARCHAR2) AS
BEGIN
EXECUTE IMMEDIATE 'DROP TABLE ' || table_name;
END;
/
Use concatenation to build the string,
rather than trying to pass the table
name as a bind variable through the
USING clause.
In addition, if you need to call a
procedure whose name is unknown until
runtime, you can pass a parameter
identifying the procedure. For
example, the following procedure can
call another procedure (drop_table) by
specifying the procedure name when
executed.
CREATE PROCEDURE run_proc (proc_name IN VARCHAR2, table_name IN VARCHAR2) ASBEGIN
EXECUTE IMMEDIATE 'CALL "' || proc_name || '" ( :proc_name )' using table_name;
END;
/
If you want to drop a table with the
drop_table procedure, you can run the
procedure as follows. Note that the
procedure name is capitalized.
CREATE TABLE employees_temp AS SELECT last_name FROM employees;
BEGIN
run_proc('DROP_TABLE', 'employees_temp');
END;
/
Here are a couple of possibilities. First, you would have to treat the SQL as dynamic SQL. Second, Oracle DDL statements cannot be run in a transaction (or, they terminate the current transaction and cannot themselves be rolled back). This may affect whether you can use them in stored procedures, or where you can use stored procedures that contain them.
If none of the above apply at all - there could easily be something else astray - I suggest posting some code.