Check a record IS NOT NULL in plsql - plsql

I have a function which would return a record with type my_table%ROWTYPE, and in the caller, I could check if the returned record is null, but PL/SQL complains the if-statement that
PLS-00306: wrong number or types of arguments in call to 'IS NOT NULL'
Here is my code:
v_record my_table%ROWTYPE;
v_row_id my_table.row_id%TYPE := 123456;
begin
v_record := myfunction(v_row_id)
if (v_record is not null) then
-- do something
end if;
end;
function myfunction(p_row_id in my_table.row_id%TYPE) return my_table%ROWTYPE is
v_record_out my_table%ROWTYPE := null;
begin
select * into v_record_out from my_table
where row_id = p_row_id;
return v_record_out;
end myfunction;
Thanks.

As far as I know, it's not possible. Checking the PRIMARY KEY or a NOT NULL column should be sufficient though.
You can check for v_record.row_id IS NULL.
Your function would throw a NO_DATA_FOUND exception though, when no record is found.

You can't test for the non-existence of this variable so there are two ways to go about it. Check for the existence of a single element. I don't like this as it means if anything changes your code no longer works. Instead why not just raise an exception when there's no data there:
I realise that the others in the exception is highly naughty but it'll only really catch my table disappearing when it shouldn't and nothing else.
v_record my_table%ROWTYPE;
v_row_id my_table.row_id%TYPE := 123456;
begin
v_record := myfunction(v_row_id)
exception when others then
-- do something
end;
function myfunction(p_row_id in my_table.row_id%TYPE) return my_table%ROWTYPE is
v_record_out my_table%ROWTYPE := null;
cursor c_record_out(c_row_id char) is
select *
from my_table
where row_id = p_row_id;
begin
open c_record_out(p_row_id);
fetch c_record_out into v_record_out;
if c_record_out%NOTFOUND then
raise_application_error(-20001,'no data);
end if;
close c_record_out;
return v_record_out;
end myfunction;

Related

Can anyone help whey my execption section is not working,

My whole intention to catch exception,WRONG parameter is NOT CATCHING exception.
Here is the code:
CREATE OR REPLACE PROCEDURE list_emp (p_emp_id IN employees.employee_id%TYPE,
p_dept_id IN employees.department_id%TYPE)
IS
CURSOR c1 IS
SELECT *
FROM EMPLOYEES
WHERE EMPLOYEE_ID=p_emp_id
AND DEPARTMENT_ID=p_dept_id;
emp_rec c1%ROWTYPE;
BEGIN
OPEN c1;
LOOP
FETCH c1 INTO emp_rec;
EXIT WHEN c1%NOTFOUND;
DBMS_OUTPUT.PUT_LINE(emp_rec.employee_id||' '||emp_rec.first_name||' '||emp_rec.last_name);
END LOOP;
CLOSE c1;
EXCEPTION
WHEN NO_DATA_FOUND THEN
DBMS_OUTPUT.PUT_LINE('No Record Found ');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('No Record Found ');
END;
When the cursor is opened and fetched with the wrong parameter that does not match any row from the corresponding table, the following line
EXIT WHEN c1%NOTFOUND;
cause the plsql procedure to terminate (because there were no rows found). Hence no exception is raised.
If you do want to display some sort of output you can do the following instead
IF c1%FOUND THEN
dbms_output.put_line('Record Found');
ELSE
dbms_output.put_line('Finished/Done');
EXIT;
END IF;
If you want to raise an error after looping through a cursor that returns no rows, then you're going to have to use a counter to work out how many rows have been processed, and then you can do something if no rows have been processed.
Something like:
create or replace procedure list_emp (p_emp_id in employees.employee_id%type,
p_dept_id in employees.department_id%type)
is
cursor c1 is
select employee_id,
first_name,
last_name
from employees
where employee_id = p_emp_id
and department_id = p_dept_id;
v_count number := 0;
begin
for emp_rec in c1
loop
v_count := v_count + 1;
dbms_output.put_line(emp_rec.employee_id||' '||emp_rec.first_name||' '||emp_rec.last_name);
end loop;
if v_count = 0 then
raise no_data_found;
end if;
exception
when no_data_found then
dbms_output.put_line('No Record Found.');
raise;
when others then
dbms_output.put_line('An error occurred: '||sqlerrm);
raise;
end;
/
A few notes:
I converted your cursor loop into a cursor-for-loop; you don't need to worry about declaring the record type and also Oracle handles the opening and closing of the cursor for you.
I added raise; to each of your exception handlers - in general, having when others then null (which is effectively what your original code was doing - no errors are raised to the calling code) is a bad idea. I added the raise to the no_data_found condition as that wasn't doing anything either; typically, if you have an exception condition, you want it to do something to let the calling code know there was a problem (not always, of course; sometimes you don't want the processing to stop if a particular error condition is met).
Your cursor was selecting all columns, but in your procedure, you were only using three of them. I've therefore amended the cursor so that it only pulls back those three columns.
Don't rely on dbms_output in your production code. Code that calls this procedure won't see anything populated in dbms_output, unless it explicitly looks for it - and that's not something I've ever seen in any production code, outside of Database tools (eg. SQL*Plus, Toad, etc). I've left this in your procedure as I've a feeling this is a learning exercise for you, but please don't think that this is in any way acceptable in production code.
You're passing p_emp_id in as a parameter - typically, that's the primary key of the employees table. If that's the case, then there's no need for the cursor for loop at all - you could do it by using select ... into ... instead, like so:
.
create or replace procedure list_emp (p_emp_id in employees.employee_id%type,
p_dept_id in employees.department_id%type)
is
v_emp_id employees.employee_id%type;
v_first_name employees.first_name%type;
v_last_name employees.last_name%type;
begin
select employee_id,
first_name,
last_name
into v_emp_id,
v_first_name,
v_last_name
from employees
where employee_id = p_emp_id
and department_id = p_dept_id;
dbms_output.put_line(emp_rec.employee_id||' '||emp_rec.first_name||' '||emp_rec.last_name);
exception
when no_data_found then
dbms_output.put_line('No Record Found.');
raise;
when others then
dbms_output.put_line('An error occurred: '||sqlerrm);
raise;
end;
/
Alternatively, just pass back a ref cursor:
create or replace procedure list_emp (p_emp_id in employees.employee_id%type,
p_dept_id in employees.department_id%type,
p_ref_cur out sys_refcursor)
is
begin
open p_ref_cur for select employee_id,
first_name,
last_name
from employees
where employee_id = p_emp_id
and department_id = p_dept_id;
-- No need for an exception handler here since you're not storing the error details anyway.
-- By not having an error handler, any error will automatically be raised up to the calling code
-- and it will have the correct error stack trace info (e.g. the line number the error occurred,
-- rather than the line the error was reraised from
end;
/
And to run the ref cursor in SQL*Plus (or as a script in Toad/SQL Developer/etc), you do the following:
-- create a variable outside of PL/SQL to hold the ref cursor pointer (this is a SQL*Plus command):
variable rc refcursor;
-- populate our ref cursor variable with the pointer. Note how we pass it in as a bind variable
begin
list_emp(p_emp_id => 1234,
p_dept_id => 10,
p_ref_cur => :rc);
end;
/
-- finally, print the contents of the ref cursor.
print rc;

open, fetch, into multiple variables

I am trying to get 2 variables out of a cursor without using a loop.
CREATE OR REPLACE PROCEDURE NAK.SET_ORDERS(P_ORDER_ID NAK.ORDER_ID%TYPE)
CURSOR C_GET_ORDER_NO IS
SELECT O.ORDER_ID, O.ORDER_MAL FROM NAK.ORDERS O WHERE O.ORDER_ID = P_ORDER_ID;
BEGIN
V_ORDER_SEQ := NULL;
V_ORDER_MAL := NULL;
OPEN C_GET_ORDER_NO;
FETCH C_GET_ORDER_NO VALUES(O.ORDER_ID, O.ORDER_MAL)
INTO (V_ORDER_ID, V_ORDER_MAL);
CLOSE C_GET_ORDER_NO;
END;
Do you really need an explicit cursor? You can simply do this:
CREATE OR REPLACE PROCEDURE NAK.SET_ORDERS(P_ORDER_ID IN NAK.ORDER_ID%TYPE)
V_ORDER_SEQ := NULL;
V_ORDER_MAL := NULL;
BEGIN
SELECT O.ORDER_ID,
O.ORDER_MAL
INTO V_ORDER_SEQ,
V_ORDER_MAL
FROM NAK.ORDERS O
WHERE O.ORDER_ID = P_ORDER_ID;
EXCEPTION
WHEN NO_DATA_FOUND THEN
dbms_output.put_line("No record found");
WHEN TOO_MANY_ROWS THEN
dbms_output.put_line("More than one record found");
WHEN OTHER THEN
dbms_output.put_line("Other problem happend");
END;
Important: this procedure will return a exception if the query doesn't return exactly one record. (ORA-01403: no data found or ORA-00913: too many values)
Alternatively you should be able to make something like:
CREATE OR REPLACE PROCEDURE NAK.SET_ORDERS(P_ORDER_ID NAK.ORDER_ID%TYPE)
CURSOR C_GET_ORDER_NO IS
SELECT O.ORDER_ID,
O.ORDER_MAL
FROM NAK.ORDERS O
WHERE O.ORDER_ID = P_ORDER_ID;
BEGIN
V_ORDER_SEQ := NULL;
V_ORDER_MAL := NULL;
OPEN C_GET_ORDER_NO;
FETCH C_GET_ORDER_NO INTO V_ORDER_ID, V_ORDER_MAL;
CLOSE C_GET_ORDER_NO;
END;

Oracle PL/SQL - ORA-01403 “No data found” when using “SELECT INTO”

I have a pl sql code that execute three queries sequentially to determine a match level and do some logic
The issue is - when first query has no results (completely valid scenario) I get ORA-01403 No data found.
I understand that I need to incorporate [ Exception clause when NO_DATA_FOUND ]- but how to add it and continue to the next query?
PL/SQL Code
SELECT A into PARAM A FROM SAMPLE WHERE SOME CONDITION;
-- GOT ORA-01403 No data found HERE
MATCH_LEVEL =1;
if A is null then
do some logic;
end if
SELECT A INTO PARAM_B FROM SAMPLE WHERE SOME OTHER CONDITION
MATCH_LEVEL =2
if A is null then
do some logic 2;
end if
SELECT A INTO PARAM_B FROM SAMPLE WHERE SOME OTHER CONDITION
MATCH_LEVEL =3
if A is null then
do some logic 3;
end if
END PL/SQL Code
Declare
--your declarations
begin
SELECT A into PARAM A FROM SAMPLE WHERE SOME CONDITION;
-- GOT ORA-01403 No data found HERE
Begin
MATCH_LEVEL =1;
if A is null then
do some logic;
end if;
EXCEPTION
WHEN NO_DATA_FOUND THEN
dbms_output.put_line ('Error...');
END;
--- and son on for other blocks
end;
Just surround your SELECT INTO with begin-end;
begin
-- your faulty statement here
Exception
When NO_DATA_FOUND Then
-- Do what you want or nothing
WHEN TOO_MANY_ROWS THEN
-- what if you get more then one row? and need specific handler for this
When OTHERS Then
-- do something here or nothing (optional - may happen if you have more than your SELECT INTO between 'begin' and 'Exception')
end;
This is like try block of PL/Sql
With this technique you can log the reason your statement failed.
For a SELECT ... INTO ... statement, the PL/SQL engine assume there will be one, and only one row returned by your query. If there is no row, or more than one, an exception is raised.
FWIW, you can handle such cases without resorting on exception handling by using aggregate functions. That way, there will always be only one row in the result set.
Assuming A can't be NULL in your rows:
SELECT MAX(A) into PARAM A FROM SAMPLE WHERE SOME CONDITION;
-- A would be NULL if there was *no* row. Otherwise, it is *the* value for *the* row
MATCH_LEVEL =1;
if A is null then
do some logic;
end if
If the NULL value is a possible case, just add an extra COUNT(*) column:
SELECT MAX(A), COUNT(*) into A, HAS_FOUND_ROW FROM SAMPLE WHERE SOME CONDITION;
if HAS_FOUND_ROW > 0 then
...
end if;
Oracle will not allow you to open an implicit cursor (i.e. a select statement in the body of a code block) that returns no rows. You have two options here (3 really, counting #Sylvain's answer, but that is an unusual approach): use an explicit cursor or handle the error.
Explicit Cursor
An explicit cursor is one found in the DECLARE section it must be opened and fetched manually (or in a FOR loop). This has the added advantage that, if you parameterize the query properly, you can write it once and use it multiple times.
DECLARE
a sample.a%type;
MATCH_LEVEL number;
cursor cur_params (some_column_value number) is
SELECT A FROM SAMPLE WHERE some_column = some_column_value;
BEGIN
MATCH_LEVEL := 1;
open cur_params (match_level);
fetch cur_params into a;
close cur_params;
if A is null then
null; --some logic goes here
end if;
MATCH_LEVEL := 2;
open cur_params (match_level);
fetch cur_params into a;
close cur_params;
if A is null then
null; --some logic goes here
end if;
end;
Handle the error
If you choose to handle the error, you'll need to create a BEGIN...END block around the code that is going to throw the error. When disregarding an error, it's crucial that you ensure that you are only disregarding the specific error you want avoid, when generated from the specific statement you expect it from. If you simply add the EXCEPTION section to your existing BEGIN...END block, for instance, you couldn't know which statement generated it, or even if it was really the error you expected.
DECLARE
a sample.a%type;
MATCH_LEVEL number;
BEGIN
MATCH_LEVEL := 1;
BEGIN
SELECT A into A FROM SAMPLE WHERE some_column = MATCH_LEVEL;
EXCEPTION
WHEN NO_DATA_FOUND THEN
null; --Do nothing
END;
if A is null then
null; --some logic goes here
end if;
MATCH_LEVEL := 2;
BEGIN
SELECT A into A FROM SAMPLE WHERE some_column = MATCH_LEVEL;
EXCEPTION
WHEN NO_DATA_FOUND THEN
null; --Do nothing
END;
if A is null then
null; --some logic goes here
end if;
end;
While I'd discourage it, you can catch any other errors in the same exception blocks. However, by definition, those errors would be unexpected, so it would be a poor practice to discard them (you'll never know they even happened!). Generally speaking, if you use a WHEN OTHERS clause in your exception handling, that clause should always conclude with RAISE;, so that the error gets passed up to the next level and is not lost.

"Identifier must be declared" when using a function

I have the following function in a package body:
FUNCTION valida_salario(p_salary IN employees.salary%TYPE,
p_department_id IN employees.department_id%TYPE)
RETURN BOOLEAN IS
v_prom_depto NUMBER;
v_var_depto NUMBER;
BEGIN
SELECT AVG(salary), VARIANCE(SALARY) INTO v_prom_depto, v_var_depto
FROM employees
WHERE department_id=p_department_id;
-- GROUP BY department_id;
IF p_salary < v_prom_depto + 3* sqrt(v_var_depto) THEN
RETURN TRUE;
ELSE
RETURN FALSE;
END IF;
EXCEPTION
WHEN OTHERS THEN
dbms_output.put_line(SQLERRM);
END valida_salario;
And when I am using the function in a stored procedure (the procedure is in the body too), it show errors:
PROCEDURE crea_empleado(p_last_name IN employees.last_name%TYPE,
p_first_name IN employees.first_name%TYPE,
p_email IN employees.email%TYPE,
p_hire_date IN employees.hire_date%TYPE,
p_job_id IN employees.job_id%TYPE,
p_department_id IN employees.department_id%TYPE
DEFAULT 80,
p_resultado OUT NUMBER) AS
e_salario_no_valido EXCEPTION;
BEGIN
IF valida_salario(p_salary, p_department_id) THEN // Here is located the errors
NULL;
ELSE
RAISE e_salario_no_valido;
END IF;
INSERT INTO employees(employee_id, last_name, first_name, email, hire_date, job_id)
VALUES (emp_seq.NEXTVAL, p_last_name, p_first_name, p_email, p_hire_date, p_job_id);
EXCEPTION
WHEN DUP_VAL_ON_INDEX THEN
p_resultado := 2;
dbms_output.put_line('Datos duplicados');
WHEN e_salario_no_valido THEN
p_resultado := 1;
WHEN OTHERS THEN
dbms_output.put_line(SQLERRM);
ROLLBACK;
END crea_empleado;
The following errors are :
PL/SQL: Statement ignored and
PLS-00201: the identifier 'P_SALARY' must be declared
But I can't see the error in my function, so I don't understand why it shows these errors.
Thanks in advance for your help
You need to pass p_salary into your crea_empleado() procedure. p_department_id is there but no p_salary.

wrong number or types of arguments in call to my procedure

hi I wrote this code to create a procedure to return a Boolean value based on the if conditions but when I execute it I got this error:
ORA-06550: line 1, column 7:
PLS-00306: wrong number or types of arguments in call to 'DDPAY_SP'
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action:
here is my procedure
create or replace procedure DDPAY_SP (
donor_id dd_donor.iddonor%type,
pldgstatus out dd_pledge.idstatus%type,
monthplan out dd_pledge.paymonths%type,
ret out boolean)
IS
begin
select idstatus, paymonths into
pldgstatus, monthplan from dd_pledge
where iddonor = donor_id ;
if (pldgstatus = 10 AND monthplan >0)
then ret:= true;
else
ret:= false;
end if;
end;
and this how I execute it
EXECUTE DDPAY_SP (308);
I didn't put much talk I hope it's clear enough for you
I read online it recommends me to check the naming also the data type which I did but nothing change
any ideas
If you don't need the second and third arguments you could declare those as variables in the procedure instead of arguments, as follows:
CREATE OR REPLACE PROCEDURE DDPAY_SP(DONOR_ID IN DD_DONOR.IDDONOR%TYPE,
RET OUT BOOLEAN)
IS
nPayment_count NUMBER;
BEGIN
SELECT COUNT(*)
INTO nPayment_count
FROM DD_PLEDGE p
WHERE p.IDDONOR = DONOR_ID AND
p.IDSTATUS = 10 AND
p.PAYMONTHS > 0;
IF nPayment_count > 0 THEN
RET := TRUE;
END IF;
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('DD_PAY - exception: ' || SQLCODE || ' : ' || SQLERRM);
RAISE;
END DDPAY_SP;
I've included an example of an EXCEPTION handler at the end of DD_PAY. It's always a good idea to include at least this minimal handler so that in the event an exception occurs you'll get some indication of where the problem lies.
Because this procedure returns a BOOLEAN value, and BOOLEANs cannot (to the best of my knowledge) be used from SQL*Plus, you'll have to invoke it from a PL/SQL block, as follows:
DECLARE
bRetval BOOLEAN;
BEGIN
DD_PAY(308, bRetval);
DBMS_OUTPUT.PUT_LINE('Returned value is ' ||
CASE bRetval
WHEN TRUE THEN 'TRUE'
ELSE 'FALSE'
END);
END;
Give that a try.
EDIT: rewrote procedure based on further information from later comments.
Share and enjoy.

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