I wrote a simple pl\sql procedure to read a value on db. For the same value I use two different function to have at the end to different value.
My code
begin
select TRIM(SUBSTR(RPAD(VAL,30,'N'),1,1)),DECODE(TRIM(SUBSTR(RPAD(VAL,30,'N'),2,2)),'S',TRUE,FALSE)
into va_flag, amount_zero
from ENV
where USER = 'C' and VARIABLE = 'FLAG_BALANCE';
exception
when others then
amount_zero := FALSE;
va_flag := 'N';
end;
When I compile the procedure, I've got the error message :"ORA-00904 "FALSE" Invalid Identifier" on decode function.
amount_zero is a boolean.
Unfortunately, it won't work straightforward; the first step will have to be a select into some other datatype (varchar2 whose value is Y/N or T/F; or a number with 1/0 ... pick any you want) and then switch to a Boolean, in a separate statement. For example:
SQL> declare
2 va_flag varchar2(1);
3 amount_zero boolean;
4 amount_zero_char varchar2(10);
5 begin
6 -- first select it into a VARCHAR2 variable ...
7 select decode(1, 1, 'T', 'F'),
8 'N'
9 into amount_zero_char,
10 va_flag
11 from env
12 where cuser = 'C'
13 and variable = 'FLAG_BALANCE';
14
15 -- ... then switch to Boolean
16 amount_zero := case when amount_zero_char = 'T' then true
17 else false
18 end;
19
20 -- display it
21 dbms_output.put_line(case when amount_zero then 'it is true'
22 else 'it is false'
23 end);
24 end;
25 /
it is true
PL/SQL procedure successfully completed.
SQL>
Oracle SQL cannot work directly with boolean data type (PL/SQL can but not SQL).
You should try to replace boolean literals with another data type for example VARCHAR2 (and adapt related code):
select
TRIM(SUBSTR(RPAD(VAL,30,'N'),1,1)),
DECODE(TRIM(SUBSTR(RPAD(VAL,30,'N'),2,2)),'S','TRUE','FALSE')
into va_flag, amount_zero
from ENV
Related
I am trying to make the code posted below work, but I am receiving an error about the IF statement:
DECLARE
a number;
BEGIN
SELECT Pers_API.Is_Manager_(10018) INTO a from dual;
EXCEPTION
WHEN no_data_found THEN a := 0;
END;
IF (a >0) THEN
SELECT 1 from dual;
ELSE
SELECT 0 from dual;
END IF;
In the first block I am declaring an 'A' variable and setting it to 0 (by the way, the API call result will be 0 or 1, nothing else). The first block works fine or - at least - I do think so. But the IF block is not working and having this error:
PLS-00103:Encountered the symbol "IF"
Any help is appreciated.
Update: I have tried it this way:
DECLARE
a number:=0;
BEGIN
SELECT Pers_API.Is_Manager_(10018) INTO a from dual;
IF (:a >0) THEN
SELECT 1 from dual;
ELSE
SELECT 0 from dual;
END IF;
END;
I received the exception below:
ORA-01008: not all variables bound
Update
In other words, what I am trying to do is:
if Pers_API.Is_Manager_(10018) returns true (as 1), I have to do another select statement
if it's false (as 0), I have to return null.
Any other ideas are appreciated.
A few objections, if I may.
there's no need to select from dual in order to assign a value to a variable, when that value is returned by a function - simply assign it
exception handler seems to be superfluous. You said that the is_manager_ function returns 0 or 1 and nothing else. Therefore, it'll always return something, so - why do you expect that SELECT to return NO_DATA_FOUND? Besides, such a case should be handled by the function itself (i.e. you have to make sure that it returns 0 or 1 and nothing else)
the last paragraph you wrote is somewhat strange. You said that - if the function returns 1, you have to run another SELECT statement. Otherwise, you have to return null (while code you wrote, select 0 ... suggests a zero (0), not null); so, which one is true?
also, saying that you have to return something (null, 0, whatever) suggests that piece of code you wrote should be a function that returns a value. Is that so?
Code that actually compiles might look like in this example.
First, a function (based on Scott's schema) that checks whether an employee is a manager:
SQL> create or replace function is_manager_ (par_empno in number)
2 return number
3 is
4 /* function checks whether PAR_EMPNO belongs to a manager and returns:
5 - 1 - employee is a manager
6 - 0 - employee is NOT a manager
7 */
8 retval number := 0;
9 begin
10 select max(1)
11 into retval
12 from emp e
13 where mgr = par_empno;
14
15 return retval;
16 exception
17 when no_data_found then
18 return retval;
19 end;
20 /
Function created.
SQL>
Code you posted, rewritten so that it does something:
if an employee is a manager, returns his/her salary
otherwise, it does not
SQL> declare
2 a number := is_manager_(&&l_empno);
3 l_sal emp.sal%type;
4 begin
5 if a > 0 then
6 select sal
7 into l_sal
8 from emp
9 where empno = &&l_empno;
10 dbms_output.put_line('Employee is a manager and his/her salary is ' || l_sal);
11 else
12 null;
13 dbms_output.put_line('Employee is not a manager');
14 end if;
15 end;
16 /
Enter value for l_empno: 7698
Employee is a manager and his/her salary is 2850
PL/SQL procedure successfully completed.
SQL> undefine l_empno
SQL> /
Enter value for l_empno: 7369
Employee is not a manager
PL/SQL procedure successfully completed.
SQL> undefine l_empno
SQL> /
Enter value for l_empno: -1
Employee is not a manager
PL/SQL procedure successfully completed.
SQL>
See if you can adjust it so that it fits your needs. If not, do answer to my objections posted at the beginning of this message, and we'll see what to do next.
It appears to me that what you are really trying to achieve here is to run a query which must use the result obtained from the package function as a condition. If so, the PL/SQL block wouldn't be needed and can be written as a basic select operation.
What is still not clear from your explanation is whether your select query
SELECT 1 from dual is the actual query you are about to use in your code.Generally, in the select statement, we use CASE expression to evaluate the conditional logic, which essentially does what IF ELSE condition was supposed to do to return the desired result.The query would have a structure of this form,
SELECT
CASE
WHEN pers_api.is_manager_(10018) = 1 THEN some_expression
ELSE some_other_expression --If you omit the else condition, it defaults to null when all others are false
END
END
as
FROM DUAL;
More specifically, if you want to have the resultant expression come from another database table, the queries can take the form
SELECT
CASE
WHEN pers_api.is_manager_(10018) = 1 THEN some_expression
ELSE some_other_expression --If you omit the else condition, it defaults to null when all others are false
END
as
FROM table_to_run_query
WHERE where_clauses = some_values;
If you say that your resultant expression from the table involves many other constructs, the challenge would be to compose it in a single query cleverly to avoid any PL/SQL at all. That would be achievable, but it will require that you explain us with some sample data and expected result, as to what exactly you want,preferably in a new question.
It would not be complete if I don't mention the REFCURSOR technique to obtain results from a select query in PL/SQL. It is either through DBMS_SQL.RETURN_RESULT(Oracle 12c and above) or using a REFCURSOR bind variable running it in SQL* Plus or as Script in other tools (F5).
VARIABLE x refcursor;
DECLARE BEGIN
IF
pers_api.is_manager_(10018) = 1
THEN
OPEN :x FOR SELECT some_columns FROM some_tables;
ELSE
OPEN :x FOR SELECT some_columns FROM other_tables;
END IF;
--DBMS_SQL.RETURN_RESULT(:x); --12c and above
END;
/
PRINT x -- 11g
I've written a short procedure when a donor id is input it checks for active pledge based on status field (NUMBER for data type 10 is active, 20 is complete) and is making monthly payments and return boolean value True if all conditions are met and False if not. Before adding the DBMS output it would compile fine but I get error PLS-00306:wrong number or types of arguments in call"
Was feeling pretty good about solving this on my own but not sure where my mistakes are. Also looking for explanation (commented in code) about exception handlers. Thanks in advance for comments and teaching points!
My code:
CREATE OR REPLACE PROCEDURE DDPAY_SP
(donor_id IN NUMBER, active_pl OUT BOOLEAN)
IS
pay_count NUMBER;
BEGIN
SELECT COUNT(*)
INTO pay_count
FROM dd_pledge
WHERE iddonor = donor_id AND
idstatus = 10 AND
paymonths > 1;
IF pay_count > 1 THEN
active_pl := TRUE;
ELSE active_pl := FALSE;
END IF;
DBMS_OUTPUT.PUT_LINE('Active Pledge and paymonths: ' || active_pl);
/* want to add exception but don't understand how to choose
the handler for blocks of code that are not the Oracle defined
exceptions--Can someone explain better than book I have? I know
code should be:
EXCEPTION
WHEN .....
DBMS_OUTPUT.PUT_LINE(' '); */
END;
DBMS_OUTPUT.PUT_LINE('Active Pledge and paymonths: ' || active_pl);
You cannot pass a BOOLEAN to DBMS_OUTPUT. You could only pass string arguments, i.e. VARCHAR2 datatype.
This is the reason you get the following error:
PLS-00306:wrong number or types of arguments in call"
Ideally, you would not want any DBMS_OUTPUT to be sent to your client, since you are using an OUT parameter, that would suffice.
If you really want to print the boolean value, then you must convert it into VARCHAR2 datatype.
For example,
SQL> set serveroutput on
SQL> DECLARE
2 var_bool BOOLEAN;
3 BEGIN
4 var_bool := TRUE;
5 dbms_output.put_line('Status = '||
6 CASE
7 WHEN var_bool THEN
8 'TRUE'
9 ELSE
10 'FALSE'
11 END);
12 END;
13 /
Status = TRUE
PL/SQL procedure successfully completed.
SQL>
I have an associative array created by a type of rowtype of a table column.
To give an example, this is how it is(the table names are different, but the structure is the same):
This is the DDL of the table
CREATE TABLE employees
(
id NUMBER,
name VARCHAR2(240),
salary NUMBER
);
Here's what my procedure is doing:
DECLARE
TYPE table_of_emp
IS TABLE OF employees%ROWTYPE INDEX BY BINARY_INTEGER;
emp TABLE_OF_EMP;
BEGIN
IF emp IS NULL THEN
dbms_output.Put_line('Null associative array');
ELSE
dbms_output.Put_line('Not null');
END IF;
END;
I assume this should result in "Null associative array" being printed. However, the if condition fails and the execution jumps to the else part.
Now if I put in a for loop to print the collection values
DECLARE
TYPE table_of_emp
IS TABLE OF employees%ROWTYPE INDEX BY BINARY_INTEGER;
emp TABLE_OF_EMP;
BEGIN
IF emp IS NULL THEN
dbms_output.Put_line('Null associative array');
ELSE
dbms_output.Put_line('Not null');
FOR i IN emp.first..emp.last LOOP
dbms_output.Put_line('Emp name: '
|| Emp(i).name);
END LOOP;
END IF;
END;
then the program unit raises an exception, referencing the for loop line
ORA-06502: PL/SQL: Numeric or value error
which I presume is because of the null associative array. Is the error being raised because of null associative array?
So why is the first check failing then? What am I doing wrong?
The database server is Oracle 11g EE (version 11.2.0.3.0 64 bit)
I assume this should result in "Null associative array" being printed. That assumption is wrong for associative arrays. They exist when declared, but are empty. It would be correct for other types of PL/SQL collections:
Until you initialize it, a nested table or varray is atomically null;
the collection itself is null, not its elements. To initialize a
nested table or varray, you use a constructor, a system-defined
function with the same name as the collection type. This function
constructs collections from the elements passed to it.
You must explicitly call a constructor for each varray and nested
table variable. Associative arrays, the third kind of collection, do
not use constructors. Constructor calls are allowed wherever function
calls are allowed. Initializing and Referencing Collections
Compare:
SQL> declare
2 type varchar2_100_aa is table of varchar2(100) index by binary_integer;
3 test varchar2_100_aa;
4 begin
5 test(1) := 'Hello';
6 dbms_output.put_line(test(1));
7 end;
8 /
Hello
PL/SQL procedure successfully completed.
SQL> declare
2 type varchar2_100_va is varray(100) of varchar2(100);
3 test varchar2_100_va;
4 begin
5 test(1) := 'Hello';
6 dbms_output.put_line(test(1));
7 end;
8 /
declare
*
ERROR at line 1:
ORA-06531: Reference to uninitialized collection
ORA-06512: at line 5
Variable array done correctly:
SQL> declare
2 type varchar2_100_va is varray(10) of varchar2(100);
3 test varchar2_100_va;
4 begin
5 test := varchar2_100_va(); -- not needed on associative array
6 test.extend; -- not needed on associative array
7 test(1) := 'Hello';
8 dbms_output.put_line(test(1));
9 end;
10 /
Hello
PL/SQL procedure successfully completed.
Because the associative array is empty first and last are null, which is why your second example results in ORA-06502: PL/SQL: Numeric or value error:
SQL> declare
2 type varchar2_100_aa is table of varchar2(100) index by binary_integer;
3 test varchar2_100_aa;
4 begin
5 dbms_output.put_line(test.count);
6 dbms_output.put_line(coalesce(to_char(test.first), 'NULL'));
7 dbms_output.put_line(coalesce(to_char(test.last), 'NULL'));
8 test(1) := 'Hello';
9 dbms_output.new_line;
10 dbms_output.put_line(test.count);
11 dbms_output.put_line(coalesce(to_char(test.first), 'NULL'));
12 dbms_output.put_line(coalesce(to_char(test.last), 'NULL'));
13 end;
14 /
0
NULL
NULL
1
1
1
PL/SQL procedure successfully completed.
EDIT Also note that associative arrays can be sparse. Looping over the numbers between first and last will raise an exception for any collection that is sparse. Instead use first and next like so: (Last and prev to loop the other direction.)
SQL> declare
2 type varchar2_100_aa is table of varchar2(100) index by binary_integer;
3 test varchar2_100_aa;
4 i binary_integer;
5 begin
6 test(1) := 'Hello';
7 test(100) := 'Good bye';
8 dbms_output.put_line(test.count);
9 dbms_output.put_line(coalesce(to_char(test.first), 'NULL'));
10 dbms_output.put_line(coalesce(to_char(test.last), 'NULL'));
11 dbms_output.new_line;
12 --
13 i := test.first;
14 while (i is not null) loop
15 dbms_output.put_line(to_char(i, '999') || ' - ' || test(i));
16 i := test.next(i);
17 end loop;
18 end;
19 /
2
1
100
1 - Hello
100 - Good bye
PL/SQL procedure successfully completed.
I'm not going to answer why the first check is failing. I've never thought of doing anything like that and am quite surprised that it doesn't raise an error.
The reason why you're getting an exception raised on the loop is, as you've noted, that the index emp.first does not exist.
Rather than checking for nulls, you should really be checking for the existence of this index. Which you can do be using the .exists(i) syntax:
if not emp.exists(emp.first) then
dbms_output.put_line('Nothing in here.');
end if;
How can we define output parameter size in stored procedure?
You can't. Of course, you are in control of how much data you put into the OUT parameter in the stored procedure. If you want you can create a sized local variable to hold the data and then assign the value of that variable to the OUT parameter.
The calling program determines the size of the variable that receives the OUT parameter.
Here is a simple package which declares and uses a subtype:
SQL> create or replace package my_pkg as
2 subtype limited_string is varchar2(10);
3 procedure pad_string (p_in_str varchar
4 , p_length number
5 , p_out_str out limited_string);
6 end my_pkg;
7 /
Package created.
SQL> create or replace package body my_pkg as
2 procedure pad_string
3 (p_in_str varchar
4 , p_length number
5 , p_out_str out limited_string)
6 as
7 begin
8 p_out_str := rpad(p_in_str, p_length, 'A');
9 end pad_string;
10 end my_pkg;
11 /
Package body created.
SQL>
However, if we call PAD_STRING() in such a way that the output string exceeds the subtype's precision it still completes successfully. Bother!
SQL> var out_str varchar2(128)
SQL>
SQL> exec my_pkg.pad_string('PAD THIS!', 12, :out_str)
PL/SQL procedure successfully completed.
SQL>
SQL> select length(:out_str) from dual
2 /
LENGTH(:OUT_STR)
----------------
12
SQL>
This is annoying but it's the way PL/SQL works so we have to live with it.
The way to resolve the situaton is basically to apply DBC principles and validate our parameters. So, we can assert business rules against the inputs like this:
SQL> create or replace package body my_pkg as
2 procedure pad_string
3 (p_in_str varchar
4 , p_length number
5 , p_out_str out limited_string)
6 as
7 begin
8 if length(p_in_str) + p_length > 10 then
9 raise_application_error(
10 -20000
11 , 'Returned string cannot be longer than 10 characters!');
12 end if;
13 p_out_str := rpad(p_in_str, p_length, 'A');
14 end pad_string;
15 end my_pkg;
16 /
Package body created.
SQL>
SQL> exec my_pkg.pad_string('PAD THIS!', 12, :out_str)
BEGIN my_pkg.pad_string('PAD THIS!', 12, :out_str); END;
*
ERROR at line 1:
ORA-20000: Returned string cannot be longer than 10 characters!
ORA-06512: at "APC.MY_PKG", line 9
ORA-06512: at line 1
SQL>
Or we can assert business rules against the output like this:
SQL> create or replace package body my_pkg as
2 procedure pad_string
3 (p_in_str varchar
4 , p_length number
5 , p_out_str out limited_string)
6 as
7 l_str limited_string;
8 begin
9 l_str := rpad(p_in_str, p_length, 'A');
10 p_out_str := l_str;
11 end pad_string;
12 end my_pkg;
13 /
Package body created.
SQL>
SQL> exec my_pkg.pad_string('PAD THIS!', 12, :out_str)
BEGIN my_pkg.pad_string('PAD THIS!', 12, :out_str); END;
*
ERROR at line 1:
ORA-06502: PL/SQL: numeric or value error: character string buffer too small
ORA-06512: at "APC.MY_PKG", line 9
ORA-06512: at line 1
SQL>
In most scenarios we should do both. This is the polite way to build interfaces, because it means other routines can call our procedures with the confidence that they will return the values they say they will.
You could use a subtype in a package header and type check that in the body...
CREATE OR REPLACE PACKAGE my_test
AS
SUBTYPE my_out IS VARCHAR2( 10 );
PROCEDURE do_something( pv_variable IN OUT my_out );
END;
/
CREATE OR REPLACE PACKAGE BODY my_test
AS
PROCEDURE do_something( pv_variable IN OUT my_out )
IS
lv_variable my_out;
BEGIN
-- Work on a local copy of the variable in question
lv_variable := 'abcdefghijklmnopqrstuvwxyz';
pv_variable := lv_variable;
END do_something;
END;
/
Then when you run this
DECLARE
lv_variable VARCHAR2(30);
BEGIN
my_test.do_something( lv_variable );
DBMS_OUTPUT.PUT_LINE( '['||lv_variable||']');
END;
/
You would get the error
ORA-06502: PL/SQL: numeric or value error: character string buffer too small
Seems to go against the spirit of using an out parameter, but after Tony's comment this was the only thing I could think of to control data within the called code.
I have a stored procedure with an IN OUT parameter declared like follows:
create or replace PROCEDURE RIFATT_SEGN0_INS(pIdRifattSegn0 in OUT NUMBER,
pNumDossier IN VARCHAR2 ,
pNumConsegna IN NUMBER,
pDtConsegna IN DATE,
[..]
) AS
[..]
Whenever i call it from another procedure, how do i get the pIdRifattSegn0 parameter that is also out?
Your question isn't entirely clear. An IN OUT parameter is passed both ways, as its name implies. This means it has to be passed a variable, not a literal and you need a declare block to do that. For example:
declare
l_segn number;
begin
l_segn := 1;
-- procedure will have received value = 1
rifatt_segn0_ins(l_segn, 'x', 2, sysdate);
-- procedure may have changed value of l_segn from 1 to something else
dbms_output.put_line(l_segn);
end;
Here is an example:
SQL> create or replace PROCEDURE RIFATT_SEGN0_INS
2 ( pIdRifattSegn0 IN OUT NUMBER
3 , pNumDossier IN VARCHAR2
4 , pNumConsegna IN NUMBER
5 , pDtConsegna IN DATE
6 )
7 as
8 begin
9 dbms_output.put_line(pNumDossier);
10 dbms_output.put_line(to_char(pNumConsegna));
11 dbms_output.put_line(to_char(pDtConsegna,'yyyy-mm-dd'));
12 pIdRifattSegn0 := sqrt(pIdRifattSegn0);
13 end;
14 /
Procedure is aangemaakt.
SQL> create or replace procedure another_procedure
2 as
3 l_IdRifattSegn0 number := 4;
4 begin
5 rifatt_segn0_ins
6 ( pIdRifattSegn0 => l_IdRifattSegn0
7 , pNumDossier => '1A'
8 , pNumConsegna => 42
9 , pDtConsegna => sysdate
10 );
11 dbms_output.put_line('from another_procedure: l_IdRifattSegn0 = ' || to_char(l_IdRifattSegn0));
12 end;
13 /
Procedure is aangemaakt.
SQL> exec another_procedure
1A
42
2009-05-21
from another_procedure: l_IdRifattSegn0 = 2
PL/SQL-procedure is geslaagd.
Regards,
Rob.