Oracle PL/SQL/PL SQL/Predefined Exceptions

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If an ordering is applied, it occurs after the WHERE has been executed

 
SQL>
SQL> -- create demo table
SQL> create table Employee(
  2    empno              Number(3)  NOT NULL, -- Employee ID
  3    ename              VARCHAR2(10 BYTE),   -- Employee Name
  4    hireDate          DATE,                -- Date Employee Hired
  5    orig_salary        Number(8,2),         -- Orignal Salary
  6    curr_salary        Number(8,2),         -- Current Salary
  7    region             VARCHAR2(1 BYTE)     -- Region where employeed
  8  )
  9  /
Table created.
SQL>
SQL> create table job(
  2    empno              Number(3)  NOT NULL, -- Employee ID
  3    jobtitle           VARCHAR2(10 BYTE)    -- Employee job title
  4  )
  5  /
Table created.
SQL> -- prepare data for employee table
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(122,"Alison",to_date("19960321","YYYYMMDD"), 45000,       48000,       "E")
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(123, "James",to_date("19781212","YYYYMMDD"), 23000,       32000,       "W")
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(104,"Celia",to_date("19821024","YYYYMMDD"), 53000,       58000,        "E")
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(105,"Robert",to_date("19840115","YYYYMMDD"), 31000,      36000,        "W")
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(116,"Linda", to_date("19870730","YYYYMMDD"), 43000,       53000,       "E")
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(117,"David", to_date("19901231","YYYYMMDD"), 78000,       85000,       "W")
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(108,"Jode",  to_date("19960917","YYYYMMDD"), 21000,       29000,       "E")
  3  /
1 row created.
SQL>
SQL> -- prepare data for job table
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(101,   "Painter");
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(122,   "Tester");
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(123,   "Dediator");
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(104,   "Chemist");
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(105,   "Accountant");
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(116,   "Manager");
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(117,   "Programmer");
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(108,   "Developer");
1 row created.
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
  2  /
Hit a key to continue
     EMPNO ENAME      HIREDATE  ORIG_SALARY CURR_SALARY R
---------- ---------- --------- ----------- ----------- -
       122 Alison     21-MAR-96       45000       48000 E
       123 James      12-DEC-78       23000       32000 W
       104 Celia      24-OCT-82       53000       58000 E
       105 Robert     15-JAN-84       31000       36000 W
       116 Linda      30-JUL-87       43000       53000 E
       117 David      31-DEC-90       78000       85000 W
       108 Jode       17-SEP-96       21000       29000 E
7 rows selected.
SQL> select * from job;
Hit a key to continue
     EMPNO JOBTITLE
---------- ----------
       101 Painter
       122 Tester
       123 Dediator
       104 Chemist
       105 Accountant
       116 Manager
       117 Programmer
       108 Developer
8 rows selected.
SQL>
SQL>
SQL>
SQL> -- If an ordering is applied, it occurs after the WHERE has been executed:
SQL>
SQL> SELECT e.empno, e.ename, j.jobtitle, e.orig_salary
  2  FROM employee e, job j
  3  WHERE e.orig_salary < 43000
  4    AND e.empno = j.empno
  5  ORDER BY orig_salary desc;
     EMPNO ENAME      JOBTITLE   ORIG_SALARY
---------- ---------- ---------- -----------
       105 Robert     Accountant       31000
       123 James      Dediator         23000
       108 Jode       Developer        21000
SQL>
SQL>
SQL>
SQL>
SQL> drop table job;
Table dropped.
SQL>
SQL> -- clean the table
SQL> drop table Employee;
Table dropped.
SQL>
SQL>
SQL>



NO_DATA_FOUND Exception

SQL>
SQL>
SQL> -- create demo table
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 #6
PL/SQL procedure successfully completed.
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /
Table dropped.
SQL>
SQL>
SQL>



Predefined exceptions: WHEN ZERO_DIVIDE

 
SQL>
SQL> --Predefined exceptions
SQL> set serverout on;
SQL>
SQL> DECLARE
  2    v_num1 NUMBER := 5;
  3    v_num2 NUMBER := 0;
  4    myResult NUMBER;
  5  BEGIN
  6    myResult := v_num1/v_num2;
  7    DBMS_OUTPUT.PUT_LINE("The quotient is "||TO_CHAR(myResult));
  8  EXCEPTION
  9    WHEN ZERO_DIVIDE THEN
 10      DBMS_OUTPUT.PUT_LINE("You cannot divide by zero");
 11  END;
 12
 13  /
You cannot divide by zero
PL/SQL procedure successfully completed.
SQL>



This block illustrates the behavior of a predefined exception

    
SQL> BEGIN
  2    RAISE NO_DATA_FOUND;
  3  END;
  4  /
BEGIN
*
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 2

SQL>
SQL>



This script demonstrates the scope of exceptions.

    
SQL>
SQL> BEGIN
  2    DECLARE
  3      myException EXCEPTION;
  4    BEGIN
  5      RAISE myException;
  6    END;
  7  EXCEPTION
  8    WHEN OTHERS THEN
  9      RAISE;
 10  END;
 11  /
BEGIN
*
ERROR at line 1:
ORA-04045: errors during recompilation/revalidation of sqle.LOG_ERRORS
ORA-01031: insufficient privileges
ORA-06510: PL/SQL: unhandled user-defined exception
ORA-06512: at line 9

SQL>
SQL> CREATE OR REPLACE PACKAGE Globals AS
  2    myException EXCEPTION;
  3  END Globals;
  4  /
Package created.
SQL>
SQL> BEGIN
  2    BEGIN
  3      RAISE Globals.myException;
  4    END;
  5  EXCEPTION
  6    WHEN Globals.myException THEN
  7      RAISE;
  8  END;
  9  /
BEGIN
*
ERROR at line 1:
ORA-04045: errors during recompilation/revalidation of sqle.LOG_ERRORS
ORA-01031: insufficient privileges
ORA-06510: PL/SQL: unhandled user-defined exception
ORA-06512: at line 7

SQL>



This script demonstrates user defined exceptions

    
SQL> CREATE TABLE book (
  2    isbn      CHAR(10) PRIMARY KEY,
  3    category  VARCHAR2(20),
  4    title     VARCHAR2(100),
  5    num_pages NUMBER,
  6    price     NUMBER,
  7    copyright NUMBER(4),
  8    emp1   NUMBER,
  9    emp2   NUMBER,
 10    emp3   NUMBER
 11  );
Table created.
SQL>
SQL> INSERT INTO book (isbn, category, title, num_pages, price, copyright, emp1, emp2, emp3)
  2             VALUES ("1", "Database", "Oracle", 563, 39.99, 1999, 1, 2, 3);
1 row created.
SQL> INSERT INTO book (isbn, category, title, num_pages, price, copyright, emp1, emp2)
  2             VALUES ("2", "Database", "MySQL", 765, 44.99, 1999, 4, 5);
1 row created.
SQL> INSERT INTO book (isbn, category, title, num_pages, price, copyright, emp1, emp2, emp3)
  2             VALUES ("3", "Database", "SQL Server", 404, 39.99, 2001, 6, 7, 8);
1 row created.
SQL>
SQL>
SQL> DECLARE
  2    e_Duplicateemp EXCEPTION;
  3
  4    v_emp1 book.emp1%TYPE;
  5    v_emp2 book.emp2%TYPE;
  6    v_emp3 book.emp3%TYPE;
  7  BEGIN
  8    SELECT emp1, emp2, emp3 INTO v_emp1, v_emp2, v_emp3 FROM book WHERE title = "XML";
  9
 10    IF (v_emp1 = v_emp2) OR (v_emp1 = v_emp3) OR (v_emp2 = v_emp3) THEN
 11       RAISE e_Duplicateemp;
 12    END IF;
 13  END;
 14  /
DECLARE
*
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 8

SQL>
SQL> drop table book;
Table dropped.