Introduction - If you have any usage issues, please Google them yourself
SQL database simple routines
Equipped with a SPJ database, including S, P, J, SPJ four relationship model:
S (SNO, SNAME, STATUS, CITY)
P (PNO, PNAME, COLOR, WEIGHT)
J (JNO, JNAME, CITY)
SPJ (SNO, JNO, CITY, PNO)