-A script with an anonymous PL/SQL block
SET SERVEROUTPUT ON;
sum_balance_due_var NUMBER(9, 2);
SELECT SUM(invoice_total - payment_total - credit_total)
WHERE vendor_id = 95;
IF sum_balance_due_var > 0
Basic Retrieval Queries in SQL
One basic statement for retrieving information
from a database
SQL allows a table to have two or more
tuples that are identical in all their attribute
1.5. Figure 1-30 shows a list that is used by a veterinary office.
Describe three modification problems
that are likely to occur with using this list. (Please use one of each type.)
- The three modification problems that are likely
A Relational Model of Data for
Large Shared Data Banks
E. F. CODD
I B M Research Laboratory, San Jose, California
Future users of large data banks must be protected from
having to know how the data is organized in the machine (the
JDBC (Java Database Connectivity) uses a
library of objects and methods to allow Java
programs to set up and use connections to
Any vendor can implement a driver for the
JDBC API (Application P
Introduction to Transaction
At most one user at a time can use the system.
Many users can access the system concurrently.
Disk Storage Devices
Preferred secondary storage device for high
storage capacity and low cost.
Data stored as magnetized areas on
magnetic disk surfaces.
A disk pack contains several magnetic
Relational algebra operations work on one or
more relations to define another relation
without changing the original relations.
Both operands and results are relations, so
output from one o
Two Approaches to Database
and IS Development
System Development Life Cycle
Detailed, well-planned development process
Time-consuming, but comprehensive
Long development cycle
Everything in D2L.
Check D2L news and forum regularly
Post questions to the D2L forum when
possible rather than waiting until class
Communicate via email and D2L forum
The highest two exams, on
The syntax for an anonymous PL/SQL block
WHEN OTHERS THEN