数据库查询练习：关系代数与SQL应用.pdfVIP

Exercise1

❖Giventhefollowingtab:

employee(_name,street,city)

works(_name,company_name,salary)

company(company_name,city)

manages(_name,manager_name)

❖Answerthequestionsbyusing

RA-RelationalAlgebra

SQL-StructuredQueryLanguage

RASQL

❖Giventhefollowingtab:

employee(_name,street,city)

works(_name,company_name,salary)

company(company_name,city)

manages(_name,manager_name)

❖Findthenameofemployeeswhoearnmorethan$5,000andlivein

GuangZhou.

❖Findthenameoftheemployeeswhoarenotmanagers.

❖Findthenamesofallswhoworkfor“construction

bank”andliveinthecitywherethecompanyislocated.

❖Findtheworker(s)withhighestsalary

❖Disythenamesofallemployeeswhowork(inatleasta

comany)andthecityofthecompanyinascendingorderofnames

(onlySQL)

❖FindthenamesofallemployeeswhoearnmorethanSOME

employeeofIndustrialandCommercialBankof.(onlySQL)

employee(_name,street,city)

works(_name,company_name,alary)

company(company_name,city)

manages(_name,manager_name)

❖Findthenameofemployeeswhoearnmorethan$10,000andlivein

HongKong.

selectw._name

fromworksasw

wherew.salary10000andw._namein

(selecte._name

fromemployeease

wheree.city“HongKong”)

❖Alternativesolutions

selectw._name

fromworksasw,employeease

wherew.salary10000ande.city“HongKong”

andw._namee._name

RA