Oracle PL/SQL Tutorial/PL SQL Programming/DBMS WARNING

DBMS_WARNING package

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> PROMPT ** Set the PLSQL_WARNING level to DISABLE:ALL
** Set the PLSQL_WARNING level to DISABLE:ALL
SQL>
SQL> CALL DBMS_WARNING.SET_WARNING_SETTING_STRING("DISABLE:ALL", "SESSION");
Call completed.
SQL>
SQL>
SQL> --Create a procedure that does not include an EXIT WHEN statement in the loop
SQL>
SQL> CREATE OR REPLACE PROCEDURE compile_warning
  2  AS
  3
  4     v_title VARCHAR2(100);
  5
  6     CURSOR dbms_warning_cur
  7     IS
  8     SELECT id
  9     FROM employee;
 10
 11  BEGIN
 12
 13     OPEN dbms_warning_cur;
 14
 15     LOOP
 16     FETCH dbms_warning_cur INTO v_title;
 17     -- there should be a line to exit here
 18     -- like EXIT WHEN dbms_warning_cur%NOTFOUND
 19
 20     DBMS_OUTPUT.PUT_LINE("Titles Available: "||v_title);
 21
 22     END LOOP;
 23
 24     CLOSE dbms_warning_cur;
 25
 26  END;
 27  /
Procedure created.
SQL>
SQL> PROMPT ** The procedure compiles fine
** The procedure compiles fine
SQL>
SQL> SET SERVEROUTPUT ON ESCAPE OFF
SQL>
SQL> CALL DBMS_WARNING.SET_WARNING_SETTING_STRING("ENABLE:ALL", "SESSION");
Call completed.
SQL>
SQL> SELECT DBMS_WARNING.GET_WARNING_SETTING_STRING() WARNING_LEVEL FROM dual;

WARNING_LEVEL
------------------------
ENABLE:ALL
1 row selected.
SQL> -- Now recompile the same procedure
SQL>
SQL> ALTER PROCEDURE compile_warning COMPILE;
SP2-0805: Procedure altered with compilation warnings
SQL>
SQL> -- This shows that there is a warning message.  Type SHOW ERRORS to see what the problem is.
SQL>
SQL>
SQL> SHOW ERRORS
Errors for PROCEDURE COMPILE_WARNING:

LINE/COL   ERROR
------------------------------------------
24/4       PLW-06002: Unreachable code
SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /
Table dropped.