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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.
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