SQL Tables
We have already discussed the concept of tables in the last part, but let's just refresh our memory in terms of how tables relate to SQL. A table is a systematic way to store data. For the most part, a table is just like a spreadsheet. Tables are composed of rows (records) and each row is composed of columns (fields).
| Employee Table | |||
|---|---|---|---|
| Employee ID Number | Employee Name | Employee Phone | Salary |
| 001 | Lim Li Chuen | 654-3210 | 90,000 USD |
| 002 | Lim Sing Yuen | 651-0987 | 40,000 USD |
| 003 | Loo Soon Keat | 123-4567 | 50,000 USD |
How the tables are stored by the database you are using does not really make a difference for you. The beauty of SQL is that it works independently of the internal structure of the database. The tables could be stored as simple flat files on a local PC or as complex, networked, compressed, encrypted and proprietary data structures.
All you need to know is the table's name. If you know the name, you can use SQL to call up the table.
We'll look at manipulating tables in detail a bit later. But first, let's look at the data dictionary.
The Basics of the SQL DatabaseIntroduction to Databases for the Web | Table of Contents
The Data Dictionary
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