Databases Reference
In-Depth Information
The
WHERE
Clause
A lot happens in the
clause. This is the place where the rows (with col-
umns both actual and derived) from the list specified in the
WHERE
clause are
trimmed down to only the results you need to see. Starting with the syntax
described in Chapter 2, “SQL*Plus and iSQL*Plus Basics,” we can expand the
SELECT
SELECT
statement syntax as follows:
SELECT * | {[DISTINCT]
column
|
expression
[alias], ...}
FROM
tablename
[WHERE
condition
...
];
The
WHERE
clause may have one or more conditions, separated by
AND
and
OR
and optionally grouped in parentheses to override the default precedence.
From the perspective of the table, the
SELECT
clause slices a table vertically,
and the
WHERE
clause slices it horizontally.
SELECT
WHERE
