Database Reference
In-Depth Information
4
In this chapter, you learn how to use the
SELECT
statement to retrieve one or more
columns of data from a table.
As explained in Chapter 1, “Understanding SQL,” SQL statements are made
up of plain English terms called
keywords
. Every SQL statement is made up
of one or more keywords. The SQL statement you'll probably use most fre-
quently is the
SELECT
statement. Its purpose is to retrieve information from
one or more tables.
To use
SELECT
to retrieve table data you must, at a minimum, specify two
pieces of information—what you want to select, and from where you want to
select it.
We start with a simple SQL
SELECT
statement, as follows:
▼
Input
SELECT prod_name
FROM products;
▼
Analysis
The previous statement uses the
SELECT
statement to retrieve a single column
called
prod_name
from the
products
table. The desired column name is
specified right after the
SELECT
keyword, and the
FROM
keyword specifies the
name of the table from which to retrieve the data. The output from this state-
ment is shown in the following:
