Create the queries shall involve the following topics(create at most 3 queries for each topic)

i) Simple SQL queries (SELECT, WHERE, ORDER BY, DINSTICT)

ii) Retrieving data from multiple tables ( SELECT, WHERE, ORDER BY, BETWEEN, LIKE, NOT LIKE, NULL etc )

iii) Column functions and grouping ( SELECT, WHERE, SUM, AVG, MIN, MAX, COUNT, GROUP BY, HAVING, ORDER BY )

iv) Subqueries

PART PK PART_ID SERVID PART NUMUSED PART_PRICE PART DESC HAS CAR SERVICE PK SERV_ID PK CAR_ID MECHANIC PK MECH_ID MECH_LNAME MECH FNAME MECH_PHONENUM SERVICE FK1 MECH_ID FK2 CAR_ID SERV_DATE SERV FINISHDATE SERV_COMMENT FK CUST_ID CAR_SERIALNUM IS SERVCE BY CAR_MODEL CAR_YEAR CAR_COLOUR HAS HAS INVOICE PK INVOICE_ID FK1 SERVID INVOICE_TOTAL INVOICE_DATE CUSTOMER PK CUST_D CUST_LNAME CUSTAFNAME CUST PHONENUM CUST ADRESS CUST_CITY CUST_STATE CUST_COUNTRY CUST POSTCODE