Why doesn't this work?
Any advice or solutions are greatly appreciated.
CREATE OR REPLACE TRIGGER OverReading
BEFORE UPDATE OR INSERT ON MeterReadings
FOR EACH ROW
DECLARE
emp_counter INTEGER;
max_meter INTEGER : = 5;
BEGIN
SELECT COUNT(EmployeeId) INTO emp_counter
FROM MeterReadings
WHERE EmployeeId = :NEW.EmployeeId;
IF : OLD.EmployeeId = NEW.EmployeeId THEN
RETURN;
ELSIF emp_counter >= max_meter THEN
raise_application_error(-20900,'Employee are limited to a maximum of 5 meters');
END IF;
END;
/
The Error that is thrown to me
Three syntax errors, all of them related to : character.
When fixed, trigger compiles:
SQL> CREATE OR REPLACE TRIGGER OverReading
2 BEFORE UPDATE OR INSERT ON MeterReadings
3 FOR EACH ROW
4 DECLARE
5 emp_counter INTEGER;
6 max_meter INTEGER := 5; --> here
7 BEGIN
8 SELECT COUNT(EmployeeId) INTO emp_counter
9 FROM MeterReadings
10 WHERE EmployeeId = :NEW.EmployeeId;
11 IF :OLD.EmployeeId = :NEW.EmployeeId THEN --> 2x here
12 RETURN;
13 ELSIF emp_counter >= max_meter THEN
14 raise_application_error(-20900,'Employee are limited to a maximum of 5 meters');
15 END IF;
16 END;
17 /
Trigger created.
SQL>
However: this code will run if you insert rows one-by-one. Otherwise, it will raise mutating table error as you're selecting from the same table you're inserting into (which is not allowed). If that bothers you, there are ways to fix it. Depending on database version you use, it could be a compound trigger or a type + package option.
Related
I've been searching for a while how to resolve this issue and couldn't find anything helpful.
Why this trigger is created with compilation errors?
The warning im getting
Warning: Trigger created with compilation errors.
CREATE OR REPLACE TRIGGER peope_in_dept
AFTER INSERT OR DELETE OR UPDATE on emp
FOR EACH ROW
BEGIN
VARIABLE v NUMBER;
EXECUTE :v := count_people_in_dept(:new.deptno)
IF :v <= 0 or :v >= 10 THEN
raise_application_error(-20000,'Nieodpowiednia liczba pracownikow');
END IF;
END;
/
Syntax errors. Should be
SQL> CREATE OR REPLACE TRIGGER peope_in_dept
2 AFTER INSERT OR DELETE OR UPDATE
3 ON emp
4 FOR EACH ROW
5 DECLARE
6 v NUMBER;
7 BEGIN
8 v := count_people_in_dept (:new.deptno);
9
10 IF v <= 0
11 OR v >= 10
12 THEN
13 raise_application_error (-20000, 'Nieodpowiednia liczba pracownikow');
14 END IF;
15 END;
16 /
Trigger created.
SQL>
However, I suspect it won't work if count_people_in_dept function counts employees in emp table. Why? Because table is mutating:
SQL> UPDATE emp SET comm = 1 WHERE deptno = 10;
UPDATE emp SET comm = 1 WHERE deptno = 10
*
ERROR at line 1:
ORA-04091: table SCOTT.EMP is mutating, trigger/function may not see it
ORA-06512: at "SCOTT.COUNT_PEOPLE_IN_DEPT", line 6
ORA-06512: at "SCOTT.PEOPE_IN_DEPT", line 4
ORA-04088: error during execution of trigger 'SCOTT.PEOPE_IN_DEPT'
SQL>
Now, it depends on what you really are doing in that function. One way out is to set the function to be an autonomous transaction; another one is to use compound trigger; the third option is to use custom type and a package. Or, modify the process altogether (i.e. avoid the trigger).
Why this trigger is created with compilation errors?
Because you are trying to create a SQL/Plus global bind variable inside a PL/SQL procedure and then using EXECUTE rather than just calling the function (and you missed a ; statement terminator).
The correct syntax would be:
FOR EACH ROW
DECLARE
v NUMBER;
BEGIN
v := count_people_in_dept(:new.deptno);
IF v <= 0 or v >= 10 THEN
Then it would compile. However, it still won't work as the table would be mutating as the trigger is running.
Instead, you can use a statement trigger rather than a row trigger:
CREATE OR REPLACE TRIGGER people_in_dept
AFTER INSERT OR DELETE OR UPDATE on emp
DECLARE
v_count PLS_INTEGER;
BEGIN
SELECT 1
INTO v_count
FROM dept d
LEFT OUTER JOIN emp e
ON (e.deptno = d.deptno)
GROUP BY d.deptno
HAVING COUNT(e.deptno) NOT BETWEEN 1 AND 9
FETCH FIRST ROW ONLY;
raise_application_error(-20000,'Nieodpowiednia liczba pracownikow');
EXCEPTION
WHEN NO_DATA_FOUND THEN
-- Do nothing.
NULL;
END;
/
db<>fiddle here
You could also write it as a compound trigger that aggregates the changes in deptno and then only checks the changed values using your function; however, that is a lot more complicated.
this is my code for procedure. i have created two tables as Stud_Marks and Result with some data in it...and then i have created this procedure. at run time it shows error for "object SYS.FIND_CLASS is invalid".
SQL> create or replace procedure find_class(roll IN number) IS
2 tm number (10);
3 begin
4 select total_marks into tm from stud_marks where name IN(select name from result where roll=roll_no);
5 if(tm<=1500 and tm>=990)then
6 update result set class='distin' where roll_no=roll;
7 elseif(tm>900 and tm<989)then
8 update result set class='first' where roll_no=roll;
9 elseif(tm<=899 and tm>=825)then
10 update result set class='second' where roll_no=roll;
11 end if;
12 exception when no_data_found then
13 dbms_output.put_line('roll no is not matched with the entry');
14 end;
15 /
[enter image description here][1]
Warning: Procedure created with compilation errors
.
SQL> declare
2 r number(10);
3 begin
4 r:=&roll_no;
5 find_class(r);
6 end;
7 /
Enter value for roll_no: 1
old 4: r:=&roll_no;
new 4: r:=1;
find_class(r);
*
ERROR at line 5:
ORA-06550: line 5, column 1:
PLS-00905: object SYS.FIND_CLASS is invalid
ORA-06550: line 5, column 1:
PL/SQL: Statement ignored
then i am getting an error for find_class(r)..why???
Before calling the procedure, you must make sure it is valid. Yours isn't so Oracle raises an error.
Once you created it, you got a message saying
Warning: Procedure created with compilation errors
You should have checked what's wrong by running command
show err
I reformatted code you posted - see how it is easier to read:
create or replace procedure find_class(roll IN number) IS
tm number (10);
begin
select total_marks
into tm
from stud_marks
where name IN (select name
from result
where roll = roll_no
);
if (tm <= 1500 and tm >= 990)then
update result set
class = 'distin'
where roll_no = roll;
elsif (tm > 900 and tm < 989) then --> ELSIF, not ELSEIF
update result set
class = 'first'
where roll_no = roll;
elsif (tm <= 899 and tm >= 825) then --> ELSIF, not ELSEIF
update result set
class = 'second'
where roll_no = roll;
end if;
exception when no_data_found then
dbms_output.put_line('roll no is not matched with the entry');
end;
Apparently, you used ELSEIF while it should be ELSIF. I don't know whether that's the only error as I don't have your tables - you'll find that out. Don't forget to show err if necessary!
So, once it is created without errors, you can call it and see what it does.
P.S. Forgot to mention: why do you do it connected as SYS? That user owns the database and should not be used for development or educational purposes. You should use one of predefined users (such as Scott or HR) or create your own user. Leave SYS alone.
I am new to PL/SQL and I am stuck on some code.
I am wanting to ask the user for a number and then I want to be able to use this number in an IF THEN statement to verify if the number is greater than or less than 20.
I am stuck on how to obtain user input and once I have it, I can store it and give it back to the user and verify its greater than or less than 20.
DECLARE
a number(2) := 10;
BEGIN
a:= 10;
-- check the boolean condition using if statement
IF( a < 20 ) THEN
-- if condition is true then print the following
dbms_output.put_line('a is less than 20 ' );
END IF;
dbms_output.put_line('value of a is : ' || a);
END;
/
SQL> set serveroutput on; -- for "dbms_output.put_line" to take effect
SQL> DECLARE
a number := &i_nr; -- there's no need to restrict a non-decimal numeric variable to a length
BEGIN
--a:= 10; --no need this when initialization is in declaration section
-- check the boolean condition using if statement
IF( a < 20 ) THEN
-- if condition is true then print the following
dbms_output.put_line('a is less than 20 ' );
END IF;
dbms_output.put_line('value of a is : ' || a);
END;
/
-- it prompts you for value of &i_nr "enter a numeric value, for example 10", for string values it must be in quotes '&i_str'
In SQLPlus, you'd use "&"; in my example, it is && so that I wouldn't have to enter the same value several times (i.e. every time "a" is referenced):
SQL> begin
2 if &&a < 20 then
3 dbms_output.put_line('a is less than 20');
4 end if;
5 dbms_output.put_line('value of a is: ' || &&a);
6 end;
7 /
Enter value for a: 5
old 2: if &&a < 20 then
new 2: if 5 < 20 then
old 5: dbms_output.put_line('value of a is: ' || &&a);
new 5: dbms_output.put_line('value of a is: ' || 5);
a is less than 20
value of a is: 5
PL/SQL procedure successfully completed.
SQL>
Though, I'd say that you'd rather create a procedure with an IN parameter, such as
SQL> create or replace procedure p_test (par_a in number) is
2 begin
3 if par_a < 20 then
4 dbms_output.put_line('a is less than 20');
5 end if;
6 dbms_output.put_line('value of a is: ' || par_a);
7 end;
8 /
Procedure created.
SQL> exec p_test(15);
a is less than 20
value of a is: 15
PL/SQL procedure successfully completed.
SQL> exec p_test(34);
value of a is: 34
PL/SQL procedure successfully completed.
SQL>
i am using this loop in my procedure and taking the email ids in i but when i am trying to run i am getting no data found error, so i want to check the values storing in i
code used:
for i in ( select EMAIL
into l_user_mail
from employee A CONNECT BY PRIOR lower(EMAIL) = lower(MANAGER_EMAIL)
START WITH lower(GUID) in (select replace(lower(group_name),'_org_slack')
from dynamic_group where id = '81')
) loop
l_user_mail:=l_user_mail || i.EMAIL;
end loop;
how to check the return value of i in sql command prompt.
i want to see the values getting in i
i want to see the values getting in i
Your FOR LOOP syntax is not correct. INTO clause should not be used in For Loop. See below how you can do that.
FOR I IN
(SELECT EMAIL
FROM EMPLOYEE A
CONNECT BY PRIOR LOWER (EMAIL) = LOWER (MANAGER_EMAIL)
START WITH LOWER (GUID) IN (
SELECT REPLACE (LOWER (GROUP_NAME), '_org_slack')
FROM DYNAMIC_GROUP
WHERE ID = '81') )
LOOP
-- l_user_mail:=:P60_IDP_GROUPS;
L_USER_MAIL := L_USER_MAIL || I.EMAIL;
-- To display value of I
DBMS_OUTPUT.PUT_LINE (I.EMAIL);
END LOOP;
Demo:
SQL> DECLARE
2 L_USER_MAIL VARCHAR2 (10);
3 BEGIN
4 FOR I IN (SELECT LEVEL
5 FROM DUAL
6 CONNECT BY LEVEL < 10)
7 LOOP
8 -- l_user_mail:=:P60_IDP_GROUPS;
9 L_USER_MAIL := L_USER_MAIL || I.level;
10 DBMS_OUTPUT.PUT_LINE (I.level);
11 END LOOP;
12 END;
13 /
1
2
3
4
5
6
7
8
9
PL/SQL procedure successfully completed.
I want to use DELETE Collection Method to delete some elements in collection
such as:
create or replace procedure testloop3 (clearaaa out nestedtable) as
type nestedtable is table of varchar2(255);
reply_ref_messageIds nestedtable;
getDelete_messageIds nestedtable;
begin
select distinct r.messagebox_id bulk collect into reply_ref_messageIds from reply r;
select m.id bulk collect into getDelete_messageIds from messagebox m;
getDelete_messageIds.delete(2);
getDelete_messageIds.delete(4);
getDelete_messageIds.delete(7);
getDelete_messageIds.delete(11);
getDelete_messageIds.delete(13);
for i in getDelete_messageIds.FIRST .. getDelete_messageIds.LAST loop
dbms_output.put_line(i);
end loop;
for i in 5 .. 12 loop
dbms_output.put_line(i);
end loop;
end;
and then I debug this procedure with plsql dev
-- Created on 2013/4/4 by THINKPAD
declare
-- Local variables here
aa nestedtable;
begin
-- Test statements here
testloop3(aa);
end;
and I get the indexes of getDelete_messageIds before remove which are 1 to 15.
However: when I debug to getDelete_messageIds.delete(2); it removes index 1 and 2...I can't explain why.
And then when I debug next statement getDelete_messageIds.delete(4); it removes index 3 and 4. And then getDelete_messageIds.delete(7); only removes index 7...
I can't understand...
your procedure, as posted, is showing nothing of the sort. you are simply looping around like
for idx in 1..15 loop
(.FIRST will resolve to 1 and .LAST will resolve to 15). it does not mean there are still 15 elements in the NT.
you are not checking to see if the indexes are deleted. I think you're confused about the proper way to loop through a nested table where there are gaps.
i.e. you can see the elements are deleted:
SQL> create table messagebox(id ) as select to_char(rownum) from dual connect by level <= 15;
Table created.
SQL> create or replace procedure testloop3
2 as
3 type nestedtable is table of varchar2(255);
4 getDelete_messageIds nestedtable;
5 v_idx number;
6 begin
7 select m.id bulk collect into getDelete_messageIds from messagebox m;
8 getDelete_messageIds.delete(2);
9 getDelete_messageIds.delete(4);
10 getDelete_messageIds.delete(7);
11 getDelete_messageIds.delete(11);
12 getDelete_messageIds.delete(13);
13 v_idx := getDelete_messageIds.first;
14 while v_idx is not null
15 loop
16 dbms_output.put_line(v_idx);
17 v_idx := getDelete_messageIds.next(v_idx);
18 end loop;
19 end;
20 /
Procedure created.
SQL> exec testloop3
1
3
5
6
8
9
10
12
14
15
so 2, 4, 7, 11, 13 are deleted. exactly as expected.
you can see
DECLARE
TYPE NumList IS TABLE OF NUMBER;
n NumList := NumList(1,3,5,7);
counter INTEGER;
BEGIN
DBMS_OUTPUT.PUT_LINE('N''s first subscript is ' || n.FIRST);
DBMS_OUTPUT.PUT_LINE('N''s last subscript is ' || n.LAST);
-- When the subscripts are consecutive starting at 1,
-- it's simple to loop through them.
FOR i IN n.FIRST .. n.LAST
LOOP
DBMS_OUTPUT.PUT_LINE('Element #' || i || ' = ' || n(i));
END LOOP;
n.DELETE(2); -- Delete second element.
-- When the subscripts have gaps
-- or the collection might be uninitialized,
-- the loop logic is more extensive.
-- Start at the first element
-- and look for the next element until there are no more.
IF n IS NOT NULL THEN
counter := n.FIRST;
WHILE counter IS NOT NULL
LOOP
DBMS_OUTPUT.PUT_LINE
('Element #' || counter || ' = ' || n(counter));
counter := n.NEXT(counter);
END LOOP;
ELSE
DBMS_OUTPUT.PUT_LINE('N is null, nothing to do.');
END IF;
END;
reference Finding the First or Last Collection Element