| PL/SQL EXAMPLES | |
| -- demonstration of anonymous block | |
| DECLARE | |
| v_empno emp.empno%type; | |
| v_name emp.ename%type; | |
| v_sal emp.sal%type; | |
| v_real real := 1.234; | |
| BEGIN | |
| SELECT ename, sal | |
| INTO v_name, v_sal | |
| FROM emp | |
| WHERE empno = &v_empno; | |
| dbms_output.put_line('The salary of ' || v_name ||' is: USD '||to_char(v_sal)); | |
| dbms_output.put_line('The real is '||to_char(v_real)); | |
| EXCEPTION | |
| when NO_DATA_FOUND then | |
| dbms_output.put_line('Could not find any one!'); | |
| END; | |
| / | |
| ------------------------------------------------------------------------------------------------------------------------------ | |
| -- example of implicit cursor: SQL%NOTFOUND | |
| BEGIN | |
| update emp | |
| set sal = 5000 | |
| where empno = &my_empno; | |
| IF SQL%NOTFOUND then | |
| dbms_output.put_line('could not update anyone'); | |
| END IF; | |
| END; | |
| / | |
| ----------------------------------------------------------------------------------------------------------------------------- | |
| create or replace function check_phone(phone varchar2) return number is | |
| begin | |
| -- remove all valid char in "1234567890-()", all invalid chars remained | |
| if replace(translate(phone,' 1234567890()-',' '),' ') is not null then | |
| return 0; | |
| else | |
| return 1; | |
| end if; | |
| end check_phone; | |
| ---------------------------------------------------------------------------------------------------------------------------------------- | |
| -- demonstration of function | |
| create or replace FUNCTION square (in_value in number) RETURN number is | |
| BEGIN | |
| return (in_value*in_value); | |
| END; | |
| / | |
| select sal, square(sal) from emp; | |
| select square(5) from dual; | |
| ------------------------------------------------------------------------------------------------------------------------------------------- | |
| CREATE OR REPLACE FUNCTION get_sal | |
| (v_id IN emp.empno%TYPE) | |
| RETURN NUMBER | |
| IS | |
| v_salary emp.sal%TYPE :=0; | |
| BEGIN | |
| SELECT sal | |
| INTO v_salary | |
| FROM emp | |
| WHERE empno = v_id; | |
| RETURN (v_salary); | |
| END get_sal; | |
| / | |
| select empno, sal, get_sal(empno) from emp; | |
| VARIABLE G_SAL NUMBER | |
| EXECUTE :G_SAL := GET_SAL(7369); | |
| PRINT :G_SAL; | |
| ------------------------------------------------------------------------------------------------------------------------------------------- | |
| create or replace PROCEDURE TEST_INPUT (IN_NUM IN NUMBER) IS | |
| V_NUMBER NUMBER := 5; | |
| V_CHAR VARCHAR2(20); | |
| BAD_DATA EXCEPTION; | |
| BEGIN | |
| IF (IN_NUM < 10) THEN | |
| V_CHAR := 'SMALL NUMBER'; | |
| ELSIF (IN_NUM >= 10 AND IN_NUM < 20) THEN | |
| V_CHAR := 'GOOD NUMBER'; | |
| ELSE | |
| V_CHAR := 'BAD DATA FOUND'; | |
| raise BAD_DATA; | |
| END IF; | |
| dbms_output.put_line(v_char); | |
| EXCEPTION | |
| WHEN BAD_DATA THEN | |
| dbms_output.put_line('error entered number'); | |
| END; | |
| / | |
| ------------------------------------------------------------------------------------------------------------------------------------------ | |
| CREATE OR REPLACE PROCEDURE query_emp (v_id IN emp.empno%TYPE, | |
| v_name OUT emp.ename%TYPE, | |
| v_salary OUT emp.sal%TYPE, | |
| v_comm OUT emp.comm%TYPE) | |
| IS | |
| BEGIN | |
| SELECT ename, sal, comm | |
| INTO v_name, v_salary, v_comm | |
| FROM emp | |
| WHERE empno = v_id; | |
| END query_emp; | |
| / | |
| VARIABLE g_name varchar2(15) | |
| VARIABLE g_salary number | |
| VARIABLE g_comm number | |
| EXECUTE query_emp (7654, :g_name, :g_salary,:g_comm); | |
| print :g_name; | |
| ----------------------------------------------------------------------------------------------------------------------------------------- | |
| CREATE OR REPLACE PROCEDURE format_phone (v_phone_no IN OUT VARCHAR2) | |
| IS | |
| BEGIN | |
| v_phone_no := '(' || SUBSTR(v_phone_no,1,3) || | |
| ')' || SUBSTR(v_phone_no,4,3) || | |
| '-' || SUBSTR(v_phone_no,7); | |
| END format_phone; | |
| / | |
| VARIABLE g_phone_no varchar2(15) | |
| BEGIN :g_phone_no := '8006330575'; END; | |
| EXECUTE format_phone (:g_phone_no) | |
| ---------------------------------------------------------------------------------------------------------------------------------------- | |
| create or replace PROCEDURE sql_example(empno_num number) IS | |
| my_empno emp.empno%type; | |
| my_ename emp.ename%type; | |
| BEGIN | |
| DELETE FROM emp | |
| WHERE empno = empno_num; | |
| INSERT INTO emp (empno, ename) | |
| VALUES (1234,'Tran Hung'); | |
| SELECT empno, ename INTO my_empno, my_ename | |
| FROM emp | |
| WHERE hiredate = to_date( '01-JAN-81') ; | |
| EXCEPTION | |
| when DUP_VAL_ON_INDEX then | |
| dbms_output.put_line('duplicated'); | |
| when TOO_MANY_ROWS then | |
| dbms_output.put_line('more than one person in 81'); | |
| when NO_DATA_FOUND then | |
| dbms_output.put_line('No data found'); | |
| END; | |
| ----------------------------------------------------------------------------------------------------------------------------------------------- | |
| create or replace procedure test_double_block is | |
| e_mess char(80); | |
| BEGIN | |
| DECLARE | |
| n1 number(4); | |
| BEGIN | |
| select empno | |
| into n1 | |
| from emp | |
| --where job = 'TTT'; | |
| where job = 'CLERK'; | |
| EXCEPTION | |
| when TOO_MANY_ROWS then | |
| dbms_output.put_line('more than one CLERK person '); | |
| END; | |
| DECLARE | |
| n2 number(4); | |
| BEGIN | |
| select empno | |
| into n2 | |
| from emp | |
| where job = 'MANAGER'; | |
| EXCEPTION | |
| when TOO_MANY_ROWS then | |
| dbms_output.put_line('more than one MANAGER person '); | |
| END; | |
| EXCEPTION | |
| when OTHERS then | |
| e_mess := SUBSTR(SQLERRM,1,80); | |
| dbms_output.put_line('e_mess: ' ||e_mess); | |
| dbms_output.put_line('e_mess: ' ||SQLERRM); | |
| END; | |
| / | |
| ------------------------------------------------------------------------------------------------------------------------------------------------------ | |
| create PROCEDURE change_sal(p_per_1 NUMBER,p_per_2 NUMBER, p_deptno NUMBER) IS | |
| CURSOR c_emp IS select empno,sal from emp where deptno=p_deptno; | |
| r_emp c_emp%rowtype; | |
| v_sal NUMBER; | |
| BEGIN | |
| OPEN c_emp; | |
| LOOP | |
| FETCH c_emp INTO r_emp; | |
| EXIT WHEN c_emp%NOTFOUND ; | |
| IF r_emp.sal >1000 THEN | |
| v_sal:=r_emp.sal*p_per_2; | |
| ELSE | |
| v_sal:=r_emp.sal*p_per_1; | |
| END IF; | |
| UPDATE emp | |
| SET sal=v_sal | |
| WHERE empno=r_emp.empno; | |
| END LOOP; | |
| CLOSE c_emp; | |
| COMMIT; | |
| END; | |
| ------------------------------------------------------------------------------------------------------------------------------------------------------ | |
| create or replace PROCEDURE cursor_test (numRow number) is | |
| cursor emp_cursor is | |
| select * from emp | |
| for update; | |
| BEGIN | |
| dbms_output.put_line('ename'||' '||'empno'||' '||'sal'); | |
| for myEmp in emp_cursor loop | |
| exit when emp_cursor%ROWCOUNT > numRow or emp_cursor%notfound; | |
| dbms_output.put_line (myEmp.ename||' '||to_char(myEmp.empno) | |
| || ' '||to_char(myEmp.sal)); | |
| update emp | |
| set sal = 5000 | |
| where current of emp_cursor; | |
| end loop; | |
| commit; | |
| END; | |
| / | |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------- | |
| create or replace procedure test_cursor_for is | |
| BEGIN | |
| dbms_output.put_line ('empno'||' '||'ename'); | |
| FOR r_emp IN (select empno, ename from emp where job = 'CLERK') | |
| LOOP | |
| dbms_output.put_line (to_char(r_emp.empno)||' '||r_emp.ename); | |
| END LOOP; | |
| END; | |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------- | |
| -- demonstration of EXCEPTION_INIT PRAGMA | |
| DECLARE | |
| null_data EXCEPTION; | |
| PRAGMA EXCEPTION_INIT (null_data, -01400); | |
| BEGIN | |
| insert into emp (empno, ename) | |
| values (null,'ttt'); | |
| EXCEPTION | |
| when null_data then | |
| dbms_output.put_line('null data found'); | |
| END; | |
| / | |
| ------------------------------------------------------------------------------------------------------------------------------------------------------- | |
| DECLARE | |
| My_empno number; | |
| keep_empno number; | |
| BEGIN | |
| My_empno := 59694; | |
| SELECT empno INTO keep_empno | |
| FROM emp | |
| WHERE empno = my_empno; | |
| EXCEPTION | |
| WHEN NO_DATA_FOUND THEN | |
| DBMS_OUTPUT.PUT_LINE('No Data Found'); | |
| END; | |
| / | |
| ------------------------------------------------------------------------------------------------------------------------------------------------------- | |
| CREATE OR REPLACE PACKAGE manage_emp IS | |
| PROCEDURE add_employee | |
| (v_empno NUMBER | |
| , v_ename varchar2 | |
| ,v_job varchar2); | |
| PROCEDURE rem_employee (v_empno NUMBER); | |
| END manage_emp; | |
| / | |
| CREATE OR REPLACE PACKAGE BODY manage_emp IS | |
| PROCEDURE add_employee | |
| (v_empno NUMBER | |
| , v_ename varchar2 | |
| ,v_job varchar2) IS | |
| BEGIN | |
| INSERT INTO EMP (empno, ename, job) | |
| VALUES (v_empno, v_ename, v_job); | |
| END add_employee; | |
| PROCEDURE rem_employee (v_empno NUMBER) IS | |
| BEGIN | |
| DELETE FROM emp | |
| WHERE empno = v_empno; | |
| END rem_employee; | |
| END manage_emp; | |
| / | |
| EXECUTE MANAGE_EMP.ADD_EMPLOYEE(7899,'TRAN MINH','SALESMAN'); | |
| EXECUTE MANAGE_EMP.REM_EMPLOYEE(7876); | |
| -------------------------------------------------------------------------------------------------------------------------------------------------------- | |
| -- CREATE TRIGGER: EXAMPLE | |
| CREATE OR REPLACE TRIGGER insert_on_sunday | |
| BEFORE INSERT ON emp | |
| BEGIN | |
| IF TO_CHAR(sysdate,'DY') in ('SAT', 'SUN') then | |
| dbms_output.put_line('OK, you can INSERT'); | |
| ELSE | |
| dbms_output.put_line('You can not INSERT'); | |
| RAISE_APPLICATION_ERROR (-20500, 'You may only insert into EMP during normal hours.'); | |
| END IF; | |
| END; | |
| ------------------------------------------------------------------------------------------------------------------------------------------------------- | |
| PL/SQL EXERCISESE, | |
| *** PL/SQL subprograms 1 | |
| create or replace PROCEDURE change_emp_sal is | |
| cursor emp_cursor is | |
| select * from emp | |
| for update; | |
| BEGIN | |
| for myEmp in emp_cursor loop | |
| exit when emp_cursor%notfound; | |
| if myEmp.sal < 1000 then | |
| update emp | |
| set sal = sal*1.05 | |
| where current of emp_cursor; | |
| else | |
| update emp | |
| set sal = sal*1.15 | |
| where current of emp_cursor; | |
| end if; | |
| end loop; | |
| commit; | |
| END; | |
| / | |
| -------------------------------------------------------------------------------------------------------------------------------------------------------- | |
| *** PL/SQL subprogram: 2 | |
| create or replace PROCEDURE five_high_sal IS | |
| cursor c_five_sal is | |
| select empno, ename, sal from emp e | |
| where 5 > (select count(*) from emp where e.sal < sal); | |
| r_five_sal c_five_sal%rowtype; | |
| BEGIN | |
| dbms_output.put_line(' '); | |
| dbms_output.put_line('empno'||' '||'ename'||' '||'sal'); | |
| OPEN c_five_sal; | |
| LOOP | |
| FETCH c_five_sal INTO r_five_sal; | |
| EXIT when c_five_sal%NOTFOUND; | |
| dbms_output.put_line(to_char(r_five_sal.empno)||' ' || r_five_sal.ename||' ' ||to_char( r_five_sal.sal)); | |
| END LOOP; | |
| CLOSE c_five_sal; | |
| EXCEPTION | |
| when NO_DATA_FOUND then | |
| dbms_output.put_line('No data found'); | |
| when OTHERS then | |
| dbms_output.put_line('other error:'||SQLERRM); | |
| END; | |
| / | |
| ------------------------------------------------------------------------------------------------------------------------------------------------------- | |
| **** PL/SQL subprograms: 3 | |
| create or replace PROCEDURE sql_update(empno_num number) IS | |
| my_sal emp.sal%type := 6000; | |
| update_sig EXCEPTION; | |
| BEGIN | |
| update emp | |
| set sal = my_sal | |
| where empno = empno_num; | |
| if SQL%NOTFOUND then | |
| raise update_sig; | |
| end if; | |
| EXCEPTION | |
| when update_sig then | |
| dbms_output.put_line('zero row updated'); | |
| when NO_DATA_FOUND then | |
| dbms_output.put_line('No data found'); | |
| when OTHERS then | |
| dbms_output.put_line('other error:'||SQLERRM); | |
| END; | |
| / | |
| ------------------------------------------------------------------------------------------------------------------------------------------------------- | |
| select user, sysdate, rowid, rownum from sys.dual; | |
| ------------------------------------------------------------------------------------------------- | |
| PL/SQL Tables: | |
| PL/SQL tables use a primary key to give you array-like access to rows. | |
| Like the size of a database table, size of a PL/SQL table is unconstrained. That is, the number of rows in a PL/SQL table can | |
| increase dynamicalyy. So, your PL/SQL table grows as new rows are added. | |
| PL/SQL tables can have one column and a primary key, neither of which can be named. The column can belong to any | |
| scalar type, but the primary key must belong to type BINARY_INTEGER. | |
| DECLARE | |
| TYPE enameTabTyp IS TABLE OF char(10) | |
| INDEX BY BINARY_INTEGER; | |
| ---------------------------------------------------------------------------------------------------- | |
| select to_char(hiredate,'YY') year, count(empno) number_of_emps | |
| from emp | |
| group by to_char(hiredate,'YY') | |
| having count(empno) = (select max(count(empno)) from emp group by to_char(hiredate,'YY')) | |
| / | |
| ____________________________________________________________________________________________ | |
| Packaged Cursors: You can separate a cursor specification from its body for placement in a package by | |
| using the RETURN clause, as the following example: | |
| CREATE PACKAGE EMP_ACTIONS AS | |
| /* DECLARE CURSOR SPECIFICATION */ | |
| CURSOR C1 RETURN EMP%ROWTYPE; | |
| END EMP_ACTIONS; | |
| CREATE PACKAGE BODY emp_actions as | |
| /* define cursor body */ | |
| CURSOR c1 RETURN emp%ROWTYPE | |
| SELECT * FROM emp WHERE sal > 3000; | |
| ... | |
| END emp_actions; | |
| That way, you can change the cursor body without changing the cursor specification. | |
| A cursor specification has no SELECT statement because the RETURN clause defines the datatype of the | |
| result value. You can use the %ROWTYPE attribute in a RETURN clause to provide a record type | |
| that represents a row in a database table. |