What do we use SQL
commands for? A common use is to select data from the
tables located in a database. Immediately, we see two
keywords: we need to SELECT
informationFROM a
table. (Note that a table is a container that resides
in the database where the data is stored. For more information
about how to manipulate tables, go to the
Table Manipulation Section.
Hence we have the most basic SQL structure:
SELECT "column_name"
FROM "table_name"
To illustrate the above example, assume that we have
the following table:
Table Store_Information
| store_name |
Sales |
Date |
| Los Angeles |
$1500 |
Jan-05-1999 |
| San Diego |
$250 |
Jan-07-1999 |
| Los Angeles |
$300 |
Jan-08-1999 |
| Boston |
$700 |
Jan-08-1999 |
We shall use this table as an example throughout the
tutorial (this table will appear in all sections). To
select all the stores in this table, we key in,
SELECT store_name FROM
Store_Information
Result:
| store_name |
| Los Angeles |
| San Diego |
| Los Angeles |
| Boston |
Multiple column names can be selected, as well as multiple
table names
|
