Stored Procedure Function Oracle PLSQL

SQL>
SQL> --   1.  IN - The parameter can be referenced by the procedure or function. The value of the parameter can not be overwritten by the procedure or function.
SQL> -- 2. OUT - The parameter can not be referenced by the procedure or function, but the value of the parameter can be overwritten by the procedure or function.
SQL> --   3. IN OUT - The parameter can be referenced by the procedure or function and the value of the parameter can be overwritten by the procedure or function.
SQL>
SQL> -- create demo table
SQL> create table Employee(
  2    ID                 VARCHAR2(4 BYTE),
  3    First_Name         VARCHAR2(20 BYTE),
  4    Last_Name          VARCHAR2(20 BYTE),
  5    Start_Date         DATE,
  6    End_Date           DATE,
  7    Salary             Number(8,2),
  8    City               VARCHAR2(20 BYTE),
  9    Description        VARCHAR2(80 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'), 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('03','James',    'Smith',   to_date('19781212','YYYYMMDD'), to_date('19900315','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('04','Celia',    'Rice',    to_date('19821024','YYYYMMDD'), to_date('19990421','YYYYMMDD'), 2334.78, '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'), 2334.78,'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'), 2334.78,'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'), 2334.78,'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    2334.78 Vancouver            Tester
03   James                Smith                12-DEC-78 15-MAR-90    2334.78 Vancouver            Tester
04   Celia                Rice                 24-OCT-82 21-APR-99    2334.78 Vancouver            Manager
05   Robert               Black                15-JAN-84 08-AUG-98    2334.78 Vancouver            Tester
06   Linda                Green                30-JUL-87 04-JAN-96    2334.78 New York             Tester
07   David                Larry                31-DEC-90 12-FEB-98    2334.78 New York             Manager
08   James                Cat                  17-SEP-96 15-APR-02    2334.78 Vancouver            Tester
8 rows selected.
SQL>
SQL>
SQL>
SQL>     CREATE OR REPLACE Procedure UpdateMyEmployee
  2         ( name_in IN varchar2 )
  3      IS
  4          mySalary number;
  5
  6          cursor c1 is
  7          select salary
  8            from employee
  9            where first_name = name_in;
 10
 11      BEGIN
 12
 13          open c1;
 14          fetch c1 into mySalary;
 15
 16          if c1%notfound then
 17               mySalary := 9999;
 18          end if;
 19
 20          insert into employee(first_name, salary) values ( name_in, mySalary );
 21
 22          commit;
 23
 24          close c1;
 25
 26      EXCEPTION
 27      WHEN OTHERS THEN
 28            raise_application_error(-20001,'An error was encountered - '||SQLCODE||' -ERROR- '||SQLERRM);
 29      END UpdateMyEmployee;
 30      /
Procedure created.
SQL>
SQL> exec UpdateMyEmployee('Linda');
PL/SQL procedure successfully completed.
SQL>
SQL>
SQL> select * from Employee;
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    2334.78 Vancouver            Tester
03   James                Smith                12-DEC-78 15-MAR-90    2334.78 Vancouver            Tester
04   Celia                Rice                 24-OCT-82 21-APR-99    2334.78 Vancouver            Manager
05   Robert               Black                15-JAN-84 08-AUG-98    2334.78 Vancouver            Tester
06   Linda                Green                30-JUL-87 04-JAN-96    2334.78 New York             Tester
07   David                Larry                31-DEC-90 12-FEB-98    2334.78 New York             Manager
08   James                Cat                  17-SEP-96 15-APR-02    2334.78 Vancouver            Tester
     Linda                                                            2334.78
9 rows selected.
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /
Table dropped.
SQL>
SQL>