In this lesson our instructor talks about linking tables. He discusses departments table, database normalization, foreign keys, linking table, and multiple column primary keys. He ends the lesson with four require homework problems.
Database normalization is a process that involves structuring a relational database to help reduce common
Difficulties in searching data
Having large numbers of empty fields
Needing to re-structure tables frequently
Redundant storage of the same data
A foreign key is a column in one table whose value represents a primary key of another table.
A linking table contains two or more foreign key values in each row that serve to link one row of one
table with one row of another table.
Tables can use more than one column to comprise its primary key. Such a table is defined using the following
CREATE TABLE depts_items (
deptID INT UNSIGNED,
itemID INT UNSIGNED,
PRIMARY KEY (deptID, itemID)
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.