Select into statement with exception catch statement : Handle Exception « PL SQL Programming « Oracle PL/SQL Tutorial






SQL>
SQL>
SQL>
SQL> -- create demo table
SQL> create table Employee(
  2    ID                 VARCHAR2(4 BYTE)         NOT NULL primary key,
  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> SET SERVEROUTPUT ON ESCAPE OFF
SQL>
SQL> DECLARE
  2     v_employee EMPLOYEE.FIRST_NAME%TYPE;
  3  BEGIN
  4
  5     -- the first nested block
  6     BEGIN
  7        SELECT first_name
  8        INTO v_employee
  9        FROM EMPLOYEE
 10        WHERE UPPER(last_name) = 'CAT';
 11     EXCEPTION
 12        WHEN NO_DATA_FOUND
 13        THEN
 14           DBMS_OUTPUT.PUT_LINE('EXCEPTION HANDLER for nested block 1');
 15           DBMS_OUTPUT.PUT_LINE('     ');
 16           NULL;
 17     END;
 18
 19     -- the second nested block
 20     BEGIN
 21        SELECT first_name
 22        INTO v_employee
 23        FROM EMPLOYEE
 24        WHERE UPPER(last_name) = 'HARDMAN';
 25
 26     EXCEPTION
 27        WHEN TOO_MANY_ROWS
 28        THEN
 29           DBMS_OUTPUT.PUT_LINE('     ');
 30           DBMS_OUTPUT.PUT_LINE('EXCEPTION HANDLER for nested block 2');
 31           DBMS_OUTPUT.PUT_LINE('If this is printing, then the both nested');
 32           DBMS_OUTPUT.PUT_LINE('blocks'' exception handler worked!');
 33     END;
 34  END;
 35  /
DECLARE
*
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 21


SQL>
SQL>
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /

Table dropped.








24.15.Handle Exception
24.15.1.Code with No Exception Handler
24.15.2.Code with Conditional Control to Avoid an Exception
24.15.3.Code with Explicit Handler for Predefined Exception
24.15.4.Handling an Unnamed Exception
24.15.5.Handling a custom exception
24.15.6.An example showing continuing program execution after handling exception
24.15.7.The OTHERS Exception Handler
24.15.8.Assigning a Name to Predefined Exception Code
24.15.9.Using SQLCODE for error code and SQLERRM for error message
24.15.10.Catch custom exception
24.15.11.Handling exceptions without halting the program
24.15.12.Select into statement with exception catch statement
24.15.13.Check OTHERS exception
24.15.14.Error message code and text
24.15.15.Using PRAGMA EXCEPTION_INIT
24.15.16.NO data found
24.15.17.TOO_MANY_ROWS Exception
24.15.18.Use a nested block to catch exceptions from singleton SELECT.