Oracle PL/SQL/PL SQL/Exception Range
Содержание
Add a WHEN OTHERS handler to catch all runtime exceptions.
<source lang="sql">
SQL> SQL> SQL> CREATE TABLE session (
2 department CHAR(3), 3 course NUMBER(3), 4 description VARCHAR2(2000), 5 max_lecturer NUMBER(3), 6 current_lecturer NUMBER(3), 7 num_credits NUMBER(1), 8 room_id NUMBER(5) 9 );
Table created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("HIS", 101, "History 101", 30, 11, 4, 20000);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("HIS", 301, "History 301", 30, 0, 4, 20004);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("CS", 101, "Computer Science 101", 50, 0, 4, 20001);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("ECN", 203, "Economics 203", 15, 0, 3, 20002);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("CS", 102, "Computer Science 102", 35, 3, 4, 20003);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("MUS", 410, "Music 410", 5, 4, 3, 20005);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("ECN", 101, "Economics 101", 50, 0, 4, 20007);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("NUT", 307, "Nutrition 307", 20, 2, 4, 20008);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("MUS", 100, "Music 100", 100, 0, 3, NULL);
1 row created. SQL> SQL> CREATE TABLE myLogTable (
2 code NUMBER, 3 message VARCHAR2(200), 4 info VARCHAR2(100) 5 );
Table created. SQL> SQL> DECLARE
2 myException EXCEPTION;
3
4 studentCount NUMBER(3);
5
6 studentMax NUMBER(3);
7 BEGIN
8 SELECT current_lecturer, max_lecturer
9 INTO studentCount, studentMax
10 FROM session
11 WHERE department = "HIS" AND course = 101;
12
13 IF studentCount > studentMax THEN
14 RAISE myException;
15 END IF;
16 EXCEPTION
17 WHEN myException THEN
18 INSERT INTO myLogTable (info)
19 VALUES ("History 101 has " || studentCount ||
20 "lecturer: max allowed is " || studentMax);
21 WHEN OTHERS THEN
22 INSERT INTO myLogTable (info) VALUES ("Another error occurred");
23 END;
24 /
PL/SQL procedure successfully completed. SQL> SQL> SQL> select * from myLogTable; no rows selected SQL> SQL> drop table myLogTable; Table dropped. SQL> drop table session; Table dropped.
</source>
A WHEN OTHERS handler that records which runtime error occurred.
<source lang="sql">
SQL> SQL> SQL> CREATE TABLE session (
2 department CHAR(3), 3 course NUMBER(3), 4 description VARCHAR2(2000), 5 max_lecturer NUMBER(3), 6 current_lecturer NUMBER(3), 7 num_credits NUMBER(1), 8 room_id NUMBER(5) 9 );
Table created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("HIS", 101, "History 101", 30, 11, 4, 20000);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("HIS", 301, "History 301", 30, 0, 4, 20004);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("CS", 101, "Computer Science 101", 50, 0, 4, 20001);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("ECN", 203, "Economics 203", 15, 0, 3, 20002);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("CS", 102, "Computer Science 102", 35, 3, 4, 20003);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("MUS", 410, "Music 410", 5, 4, 3, 20005);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("ECN", 101, "Economics 101", 50, 0, 4, 20007);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("NUT", 307, "Nutrition 307", 20, 2, 4, 20008);
1 row created. SQL> SQL> INSERT INTO session(department, course, description, max_lecturer, current_lecturer, num_credits, room_id)
2 VALUES ("MUS", 100, "Music 100", 100, 0, 3, NULL);
1 row created. SQL> SQL> CREATE TABLE myLogTable (
2 code NUMBER, 3 message VARCHAR2(200), 4 info VARCHAR2(100) 5 );
Table created. SQL> SQL> DECLARE
2 myException EXCEPTION;
3
4 studentCount NUMBER(3);
5
6 studentMax NUMBER(3);
7
8 v_ErrorCode myLogTable.code%TYPE;
9 v_ErrorText myLogTable.message%TYPE;
10 BEGIN
11 SELECT current_lecturer, max_lecturer
12 INTO studentCount, studentMax
13 FROM session
14 WHERE department = "HIS" AND course = 101;
15
16 IF studentCount > studentMax THEN
17 RAISE myException;
18 END IF;
19 EXCEPTION
20 WHEN myException THEN
21 INSERT INTO myLogTable (info)
22 VALUES ("History 101 has " || studentCount ||
23 "lecturer: max allowed is " || studentMax);
24 WHEN OTHERS THEN
25 v_ErrorCode := SQLCODE;
26 v_ErrorText := SUBSTR(SQLERRM, 1, 200);
27 INSERT INTO myLogTable (code, message, info) VALUES
28 (v_ErrorCode, v_ErrorText, "Oracle error occurred");
29 END;
30 /
PL/SQL procedure successfully completed. SQL> SQL> SQL> SQL> select * from myLogTable; no rows selected SQL> SQL> drop table myLogTable; Table dropped. SQL> drop table session; Table dropped.
</source>
Exception Range in action
<source lang="sql">
SQL> create table Employee(
2 ID VARCHAR2(4 BYTE) NOT NULL, 3 First_Name VARCHAR2(10 BYTE), 4 Last_Name VARCHAR2(10 BYTE), 5 Start_Date DATE, 6 End_Date DATE, 7 Salary Number(8,2), 8 City VARCHAR2(10 BYTE), 9 Description VARCHAR2(15 BYTE) 10 ) 11 /
Table created. SQL> SQL> -- prepare data SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values ("01","Jason", "Martin", to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto", "Programmer")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("02","Alison", "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 6661.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("03","James", "Smith", to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 6544.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("04","Celia", "Rice", to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2344.78, "Vancouver","Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("05","Robert", "Black", to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 2334.78, "Vancouver","Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("06","Linda", "Green", to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 4322.78,"New York", "Tester")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("07","David", "Larry", to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 7897.78,"New York", "Manager")
3 /
1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)
2 values("08","James", "Cat", to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 1232.78,"Vancouver", "Tester")
3 /
1 row created. SQL> SQL> SQL> SQL> -- display data in the table SQL> select * from Employee
2 /
ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION
---------- ---------- --------- --------- ---------- ---------- ---------------
01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer 02 Alison Mathews 21-MAR-76 21-FEB-86 6661.78 Vancouver Tester 03 James Smith 12-DEC-78 15-MAR-90 6544.78 Vancouver Tester 04 Celia Rice 24-OCT-82 21-APR-99 2344.78 Vancouver Manager 05 Robert Black 15-JAN-84 08-AUG-98 2334.78 Vancouver Tester 06 Linda Green 30-JUL-87 04-JAN-96 4322.78 New York Tester 07 David Larry 31-DEC-90 12-FEB-98 7897.78 New York Manager 08 James Cat 17-SEP-96 15-APR-02 1232.78 Vancouver Tester 8 rows selected. SQL> SQL> SQL> SQL> SQL> begin
2 begin
3 begin
4 begin
5 begin
6 declare
7 myFirstName employee.first_name%type;
8 begin
9 select first_name into myFirstName from employee where 1=2;
10 -- exception
11 -- when NO_DATA_FOUND then
12 -- dbms_output.put_line("block #6");
13 end;
14 exception
15 when NO_DATA_FOUND then
16 dbms_output.put_line("block #5");
17 end;
18 exception
19 when NO_DATA_FOUND then
20 dbms_output.put_line("block #4");
21 end;
22 exception
23 when NO_DATA_FOUND then
24 dbms_output.put_line("block #3");
25 end;
26 exception
27 when NO_DATA_FOUND then
28 dbms_output.put_line("block #2");
29 end;
30 exception
31 when NO_DATA_FOUND then
32 dbms_output.put_line("block #1");
33 end;
34 /
block #5 PL/SQL procedure successfully completed. SQL> SQL> SQL> -- clean the table SQL> drop table Employee
2 /
Table dropped. SQL> SQL>
</source>
Inner exception and outter exception
<source lang="sql">
SQL> SQL> -- Inner exception and outter exception SQL> SQL> SQL> begin
2 declare
3 l_number number default "MY NUMBER";
4 begin
5 null;
6 exception
7 when OTHERS then
8 dbms_output.put_line("Exception caught in inner block");
9 end;
10 exception
11 when others then
12 dbms_output.put_line("Exception caught in outer block");
13 raise;
14 end;
15 /
Exception caught in outer block
begin
ERROR at line 1: ORA-06502: PL/SQL: numeric or value error: character to number conversion error ORA-06512: at line 13
SQL>
</source>
Raising a dynamic exception without previously declaring a user-defined EXCEPTION variable:
<source lang="sql">
SQL> SQL> BEGIN
2 RAISE_APPLICATION_ERROR(-20001,"A not too original message."); 3 EXCEPTION 4 WHEN others THEN 5 dbms_output.put_line(SQLERRM); 6 END; 7 /
ORA-20001: A not too original message. PL/SQL procedure successfully completed.
</source>
