دانلود رایگان پاورپوینت پردازش پرس و جو (انگلیسی)

Optimising Query Trees

For every project located in Stafford, retrieve the project number, the controlling department number, and the department manager’s last name, address and birth date SELECT PNUMBER, DNUM, LNAME, ADDRESS, DATE FROM PROJECT, DEPARTMENT, EMPLOYEE WHERE DNUM=DNUMBER AND MGRSSN=SSN AND PLOCATION=‘Stafford’