Syntax to declare parameterized cursor:

CURSOR cursor_name (variable_name datatype) IS <SELECT statement…>

Syntax to open a Parameterized cursor and passing values to the
cursor:
OPEN cursor_name (value/variable/expression);

The scope of cursor parameters is local to that cursor, which
means that they can be referenced only within the query declared in the
cursor declaration. Each parameter in the declaration must have a
corresponding value in the open statement.

Example: Consider a PL/SQL code to calculate the total salary of
first n records of emp table. The value of n is passed to cursor as
parameter.
Solution:

DECLARE
E NUMBER(5);
S NUMBER(5):=0;
CURSOR C1(N NUMBER) IS SELECT SAL FROM EMP WHERE ROWNUM<=N;
BEGIN
OPEN C1(&N);
LOOP
FETCH C1 INTO E;
EXIT WHEN C1%NOTFOUND;
S:=S+E;
END LOOP;
DBMS_OUTPUT.PUT_LINE(S);
CLOSE C1;
END;
With Cursor FOR Loop
DECLARE
S NUMBER(5):=0;
CURSOR C1(N NUMBER) IS SELECT SAL FROM EMP WHERE
ROWNUM<=N;
BEGIN
FOR REC IN C1(&N) LOOP
S:=S+REC.SAL;
END LOOP;
DBMS_OUTPUT.PUT_LINE(S);
END;

>> Opens a cursor.

>> Fetches a row from the cursor for each loop iteration.

>> Closes the cursor when all rows have been processed.
Example:Consider a PL/SQL code to display the employee number, employee name, job of employees of Department ‘Database Security’ with CURSOR FOR Loop

Solution:

DECLARE
CURSOR C1 IS SELECT EMP_NO, EMP_NAME, EMP_JOB FROM EMP
WHERE EMP_DEPT=’DataBase Security’;

/*EMP_REC is a row type variable for cursor c1    record,containing  empno, empname and job*/

EMP_REC C1%ROWTYPE;

BEGIN
FOR REC IN C1
LOOP
FETCH C1 INTO EMP_REC;
EXIT WHEN C1%NOTFOUND;
–Printing Employee Number
DBMS_OUTPUT.PUT_LINE(‘Employee Number ‘||REC.EMP_NO);
–Printing Employee Name
DBMS_OUTPUT.PUT_LINE(‘Employee Name ‘||REC.EMP_NAME);
–Printing Employee Job
DBMS_OUTPUT.PUT_LINE(‘JOB ‘||REC.EMP_JOB);
END LOOP;
END;

Example 1:Consider a PL/SQL code to display the employee number, employee name, job of employees of Department ‘Database Security’

DECLARE
CURSOR C1 IS SELECT EMP_NO, EMP_NAME, EMP_JOB FROM EMP
WHERE EMP_DEPT=’DataBase Security’;

/*EMP_REC is a row type variable for cursor c1    record,containing  empno, empname and job*/

EMP_REC C1%ROWTYPE;

BEGIN
OPEN C1;
LOOP
FETCH C1 INTO EMP_REC;
EXIT WHEN C1%NOTFOUND;
–Printing Employee Number
DBMS_OUTPUT.PUT_LINE(‘Employee Number ‘||REC.EMP_NO);
–Printing Employee Name
DBMS_OUTPUT.PUT_LINE(‘Employee Name ‘||REC.EMP_NAME);
–Printing Employee Job
DBMS_OUTPUT.PUT_LINE(‘JOB ‘||REC.EMP_JOB);
END LOOP;
CLOSE C1;
END;

Example2: Consider a PL/SQL code to increase the salary of employee according to following rule:

Salary of department ‘System Security’ employees increased by 1000.
Salary of deportment “DataBase Security” employees increased by 2000.
Salary of department “Application Development” employees increased by 500.

DECLARE
UPDATED_SAL NUMBER(10);
CURSOR C1 IS SELECT EMP_NO, EMP_DEPT FROM EMP;

/*EMP_REC is a row type variable for cursor c1 record,containing empno, ename and job*/

EMP_REC C1%ROWTYPE;

BEGIN
OPEN C1;
LOOP
FETCH C1 INTO EMP_REC;
EXIT WHEN C1%NOTFOUND;
–Checking if Employee Belongs to Dept System Security
IF REC.EMP_DEPT=’System Security’ THEN
UPDATE EMP SET EMP_SAL=EMP_SAL+1000
WHERE EMP_NO=REC.EMP_NO;
–Checking if Employee Belongs to Dept DataBase Security
ELSIF REC.EMP_DEPT=’DataBase Security’ THEN
UPDATE EMP SET EMP_SAL=EMP_SAL+2000
WHERE EMP_NO=REC.EMP_NO;
–Checking if Employee Belongs to Dept Application Development
ELSIF REC.EMP_DEPT=’Application Development’ THEN
UPDATE EMP SET EMP_SAL=EMP_SAL+500
WHERE EMP_NO=REC.EMP_NO;
ELSE
NULL;
END IF;
END LOOP;
CLOSE C1;
END;

Example 3:Consider a PL/SQL code to calculate the total and percentage of marks of the students in four subjects from table result
The rollno and marks in each subject are stored in the database, PL/SQL
code calculate the total and percentage of each student and update the
database.

DECLARE
MARK_TOTAL NUMBER;
MARK_PERCENTAGE NUMBER;
CURSOR C1 IS SELECT * FROM RESULT;
REC C1%ROWTYPE;
BEGIN
OPEN C1;
LOOP
FETCH C1 INTO REC;
EXIT WHEN C1%NOTFOUND;
TOTAL_MARK:=REC.S1+REC.S2+REC.S3+REC.S4;
TOTAL_PERCENTAGE :=TOTAL_MARK/4;
UPDATE RESULT SET TOTAL=TOTAL_MARK,    PERCENTAGE=TOTAL_PERCENTAGE
WHERE RNO=REC.RNO;
END LOOP;
CLOSE C1;
END;