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Practical/Practical Exam/PL-SQL/P10 - Trigger.md
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Practical/Practical Exam/PL-SQL/P10 - Trigger.md
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# P10 - Trigger
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**Problem Statement:** Trigger: Write a after trigger for Insert, update and delete event considering following requirement:
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Emp(Emp_no, Emp_name, Emp_salary)
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a) Trigger should be initiated when salary tried to be inserted is less than Rs.50,000/-
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b) Trigger should be initiated when salary tried to be updated for value less than Rs. 50,000/-
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Also the new values expected to be inserted will be stored in new table Tracking(Emp_no,Emp_salary).
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---
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## Creating tables:
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```sql
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CREATE TABLE Emp(
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Emp_no NUMBER(14),
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Emp_name VARCHAR(255),
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Emp_salary NUMBER(14)
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);
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CREATE TABLE Tracking(
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Emp_no NUMBER(14),
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Emp_salary NUMBER(14)
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);
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```
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## Trigger
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```sql
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CREATE OR REPLACE TRIGGER P10
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AFTER INSERT OR UPDATE ON Emp
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FOR EACH ROW
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BEGIN
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IF inserting THEN
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IF (:New.Emp_salary < 50000) THEN
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insert into Tracking (Emp_no, Emp_salary) VALUES (:New.Emp_no, :New.Emp_salary);
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DBMS_OUTPUT.PUT_LINE('Inserting record with salary < 50000');
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END IF;
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ELSIF updating THEN
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IF (:New.Emp_salary < 50000) THEN
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UPDATE Tracking SET Emp_salary = :New.Emp_salary WHERE Emp_no = :Old.Emp_no;
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DBMS_OUTPUT.PUT_LINE('Updated value of salary < 50000 for a record');
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END IF;
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END IF;
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END;
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/
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```
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1. After performing insertion operation:
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```sql
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INSERT INTO Emp VALUES (1, 'Tanmay', 45000);
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INSERT INTO Emp VALUES (2, 'Rajesh', 35000);
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```
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<details>
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<summary>Output</summary>
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1 row(s) inserted.<br>
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Inserting record with salary < 50000<br>
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<br>
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1 row(s) inserted.<br>
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Inserting record with salary < 50000<br>
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<br>
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Tracking:<br>
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EMP_NO EMP_SALARY<br>
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1 45000<br>
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2 35000<br>
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</details>
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2. After performing update operation:
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```sql
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UPDATE Emp SET Emp_salary = 43000 WHERE Emp_no = 1;
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```
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<details>
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<summary>Output</summary>
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1 row(s) updated.<br>
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Updated value of salary < 50000 for a record<br>
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<br>
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Tracking:<br>
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EMP_NO EMP_SALARY<br>
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1 43000<br>
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2 35000<br>
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</details>
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---
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@ -3,34 +3,37 @@
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## Creating function
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## Creating function
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```sql
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```sql
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CREATE OR REPLACE FUNCTION Age_calc (p_dob IN DATE)
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CREATE OR REPLACE FUNCTION P7(
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RETURN VARCHAR IS
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dob IN DATE,
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-- declare
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f_month OUT NUMBER,
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ageOP VARCHAR2(255);
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f_day OUT NUMBER
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years NUMBER;
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)
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months NUMBER;
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RETURN NUMBER
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days NUMBER;
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IS
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current_date DATE := SYSDATE;
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year_diff NUMBER;
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month_diff NUMBER;
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day_diff NUMBER;
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BEGIN
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BEGIN
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year_diff := EXTRACT(YEAR FROM current_date) - EXTRACT(YEAR FROM dob);
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month_diff := EXTRACT(MONTH FROM current_date) - EXTRACT(MONTH FROM dob);
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day_diff := EXTRACT(DAY FROM current_date) - EXTRACT(DAY FROM dob);
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years := EXTRACT(YEAR FROM SYSDATE) - EXTRACT(YEAR FROM p_dob);
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IF (day_diff < 0) THEN
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months := EXTRACT(MONTH FROM SYSDATE) - EXTRACT(MONTH FROM p_dob);
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month_diff := month_diff - 1;
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days := EXTRACT(DAY FROM SYSDATE) - EXTRACT(DAY FROM p_dob);
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day_diff := day_diff + EXTRACT(DAY FROM last_day(add_months(SYSDATE, -1)));
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IF (days < 1) THEN
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months := months - 1;
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days := days + EXTRACT(DAY FROM LAST_DAY(ADD_MONTHS(SYSDATE, -1)));
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END IF;
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END IF;
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IF (months < 1) THEN
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IF (month_diff < 0) THEN
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years := years - 1;
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year_diff := year_diff - 1;
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months := months + 12;
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month_diff := month_diff + 12;
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END IF;
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END IF;
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ageOP := 'Given person is ' || years || ' years ' || months || ' months ' || days || ' days old.';
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f_month := month_diff;
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f_day := day_diff;
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RETURN ageOP;
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RETURN year_diff;
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END Age_calc;
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END;
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/
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/
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```
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```
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@ -38,8 +41,13 @@ END Age_calc;
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## Calling function
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## Calling function
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```sql
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```sql
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DECLARE
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years NUMBER;
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months NUMBER;
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days NUMBER;
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BEGIN
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BEGIN
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DBMS_OUTPUT.PUT_LINE(Age_calc(TO_DATE('2004-04-28', 'YYYY-MM-DD')));
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years := P7(TO_DATE('2003-12-02', 'YYYY-MM-DD'), months, days);
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DBMS_OUTPUT.PUT_LINE('Age: ' || years || ' Years ' || months || ' Months ' || days || ' Days.');
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END;
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END;
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/
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/
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