I have crated the following tables and fill them with data: Code: CREATE TABLE IPALLILOS ( ID_IPALLILOU VARCHAR2(10) PRIMARY KEY NOT NULL, HMEROMINIA_PROSLIPSIS DATE DEFAULT NOT NULL, MISTHOS NUMBER(10,2) NOT NULL, BONUS NUMBER(10,2) ); CREATE TABLE PROSOPIKA_STOIXEIA ( ID_IPALLILOU VARCHAR2(10) NOT NULL, ONOMA VARCHAR2(10) NOT NULL, EPONIMO VARCHAR2(20) NOT NULL, IMEROMINIA_GENNISIS DATE DEFAULT, FOREIGN KEY (ID_IPALLILOU) REFERENCES IPALLILOS(ID_IPALLILOU) ); CREATE TABLE APODOSI_ETOS ( ID_IPALLILOU VARCHAR2(10) NOT NULL, KERDOS NUMBER(10,2) NOT NULL, ETOS DATE DEFAULT NOT NULL, FOREIGN KEY (ID_IPALLILOU) REFERENCES IPALLILOS(ID_IPALLILOU) ); create table paragwgikothta_ipallilou( id_ipallilou varchar(10) NOT NULL sunoliko_kerdos number(10,2) NOT NULL, FOREIGN KEY (ID_IPALLILOU) REFERENCES IPALLILOS(ID_IPALLILOU) ); create table katastash_ipallilou ( id_ipallilou varchar(10) NOT NULL, oikogeniakh_katastash VARCHAR(15), paidia VARCHAR(15), pososto_anaphrias NUMBER(3) NOT NULL, FOREIGN KEY (ID_IPALLILOU) REFERENCES IPALLILOS(ID_IPALLILOU) ); INSERT INTO IPALLILOS(ID_IPALLILOU,HMEROMINIA_PROSLIPSIS,MISTHOS,BONUS) VALUES (001,TO_DATE('17-09-2008', 'DD-MM-YYYY'),550,110); INSERT INTO IPALLILOS(ID_IPALLILOU,HMEROMINIA_PROSLIPSIS,MISTHOS,BONUS) VALUES (002,TO_DATE('17-08-2002', 'DD-MM-YYYY'),750,150); INSERT INTO IPALLILOS(ID_IPALLILOU,HMEROMINIA_PROSLIPSIS,MISTHOS) VALUES ('003',to_date('10-05-1998','DD-MM-YYYY'),'1200','98'); INSERT INTO IPALLILOS(ID_IPALLILOU,HMEROMINIA_PROSLIPSIS,MISTHOS) VALUES ('004',to_date('07-08-2001','DD-MM-YYYY'),'1360','198'); INSERT INTO IPALLILOS(ID_IPALLILOU,HMEROMINIA_PROSLIPSIS,MISTHOS) VALUES ('005',to_date('10-12-1994','DD-MM-YYYY'),'1400','102'); INSERT INTO PROSOPIKA_STOIXEIA(ID_IPALLILOU,ONOMA,EPONIMO,IMEROMINIA_GENNISIS) VALUES (001,GIWRGOS,NTALARAS,TO_DATE('01-03-1965', 'DD-MM-YYYY')); INSERT INTO PROSOPIKA_STOIXEIA(ID_IPALLILOU,ONOMA,EPONIMO,IMEROMINIA_GENNISIS) VALUES (002,NIKOS,PAPPAS,TO_DATE('25-08-1974', 'DD-MM-YYYY')); INSERT INTO PROSOPIKA_STOIXEIA(ID_IPALLILOU,ONOMA,EPONIMO,IMEROMINIA_GENNISIS) VALUES('003','KWSTANTINOS','PALAIKOSTAS','TO_DATE('25-04-1975'),'DD-MM-YYYY'); INSERT INTO PROSOPIKA_STOIXEIA(ID_IPALLILOU,ONOMA,EPONIMO,IMEROMINIA_GENNISIS) VALUES('004','KSIROS','SAVVAS','TO_DATE('15-02-1875'),'DD-MM-YYYY'); INSERT INTO PROSOPIKA_STOIXEIA(ID_IPALLILOU,ONOMA,EPONIMO,IMEROMINIA_GENNISIS) VALUES('005','KWSTANTINOS','PALAIOLOGOS','TO_DATE('04-09-1968'),'DD-MM-YYYY'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES (001, 300, TO_DATE('01-01-2009', DD-MM-YYY)); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES (001, 600, TO_DATE('01-01-2011', DD-MM-YYY)); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES (001, 900, TO_DATE('01-01-2010', DD-MM-YYY)); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES (001, 700, TO_DATE('01-01-2008', DD-MM-YYY)); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES (002, 700, TO_DATE('01-01-2011', DD-MM-YYY)); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES (002, 400, TO_DATE('01-01-2010', DD-MM-YYY)); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES (002, 900, TO_DATE('01-01-2009', DD-MM-YYY)); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES (002, 100, TO_DATE('01-01-2008', DD-MM-YYY)); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('003','100000','2012'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('003','150000','2011'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('003','200000','2010'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('003','180000','2009'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('004','120000','2012'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('004','110000','2011'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('004','250000','2010'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('004','170000','2009'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('005','160000','2012'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('005','130000','2011'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('005','140000','2010'); INSERT INTO APODOSI_ETOS(ID_IPALLILOU,KERDOS,ETOS) VALUES ('005','190000','2009'); INSERT INTO PARAGWGIKOTHTA_IPALLILOU(ID_IPALLILOU,SUNOLIKO_KERDOS) VALUES (001,250000); INSERT INTO PARAGWGIKOTHTA_IPALLILOU(ID_IPALLILOU,SUNOLIKO_KERDOS) VALUES (002,410000); INSERT INTO PARAGWGIKOTHTA_IPALLILOU(ID_IPALLILOU,SUNOLIKO_KERDOS) VALUES ('003','110000'); INSERT INTO PARAGWGIKOTHTA_IPALLILOU(ID_IPALLILOU,SUNOLIKO_KERDOS) VALUES ('004','100000'); INSERT INTO PARAGWGIKOTHTA_IPALLILOU(ID_IPALLILOU,SUNOLIKO_KERDOS) VALUES ('005','150000'); INSERT INTO KATASTASH_IPALLILOU(ID_IPALLILOU,OIKOGENIAKH_KATASTASH,PAIDIA,POSOSTO_ANAPHRIAS) VALUES(001, 'EGGAMOS',2,0); INSERT INTO KATASTASH_IPALLILOU(ID_IPALLILOU,OIKOGENIAKH_KATASTASH,PAIDIA,POSOSTO_ANAPHRIAS) VALUES(002, 'DIAZEUGMENOS',3,20); INSERT INTO KATASTASH_IPALLILOU(ID_IPALLILOS,OIKOGENIAKH_KATASTASH,PAIDIA,POSOSTO_ANAPHRIAS) VALUES ('003','AGAMOS','00','0'); INSERT INTO KATASTASH_IPALLILOU(ID_IPALLILOS,OIKOGENIAKH_KATASTASH,PAIDIA,POSOSTO_ANAPHRIAS) VALUES ('004','EGAMOS','02','0'); INSERT INTO KATASTASH_IPALLILOU(ID_IPALLILOS,OIKOGENIAKH_KATASTASH,PAIDIA,POSOSTO_ANAPHRIAS) VALUES ('005','EGAMOS','03','45'); I need the following: 1. we have to create a funcion in which if in the table IPALLILOS the salary of an employee is less than 500 add 200 more. 2. Increase by 50 bonus for employees who have salary <= 1400 but the last year brought profit> = 1000 (using functions) 3. Bonus reduction at 150 for employees who the last 4 years brought profit of less than 3000 per year (using functions) 4. During data entry on the list on the table APODOSI_ETOS for each employee make sure to refresh the table paragwgikothta_ipallilou automatically using trigger (trigger based). thanks in advance for the help.