Basic Structure of EQUEL Programs
A typical EQUEL application performs the following steps:
• Connect with a database.
• Execute queries against the database.
• Disconnect from the database.
In general, you can mix EQUEL and host language statements. Specific restrictions are discussed in this chapter. The following example shows a simple EQUEL program that retrieves and prints the salary and name for employee 23:
begin program
## ename character_string (26)
## sal float
## /* connect... */
## ingres "personnel"
## /* execute queries... */
## range of e is employee
## retrieve (sal = e.salary, ename = e.empname)
## where e.empnum = 23
## {
print ename, sal
## }
## /* disconnect */
## exit
end program