DBMS L9

Restricting and Sorting Data

WHERE

Restrict the rows that are returned by using this clause

True

(True or False) Character values are case-sensitive and date values are format-sensitive

equal to

=

greater than

>

greater than or equal

>=

less than

<

less than or equal

<=

not equal to

<>, !=, ^=

BETWEEN … AND …

display rows based on a range of values

IN (set)

• match any of a list of values

• test for values in a list

LIKE

• match a character pattern

• perform wildcard searches of valid search string values

%

denotes zero or many characters

_

denotes one character

null value

IS NULL

ESCAPE Identifier

You can use this identifier to search for the actual % and _ symbols.

AND

returns TRUE if both component conditions are true

OR

returns TRUE if either component condition is true

NOT

returns TRUE if the condition is false

Rules of Precedence

AND, OR

this is an example of these two operators

OR, AND

this is an example of these two operators

ORDER BY ASC

ascending order (default)

ORDER BY DESC

descending order

Substitution Variables

Temporarily store values with single-ampersand (&) and double-ampersand (&&) substitution

Single-Ampersand (&)

Use a variable prefixed with this substitution variable to prompt the user for a value

Double-Ampersand (&&)

Use this substitution variable if you want to reuse the variable value without prompting the user each time

DEFINE

command to create and assign a value to a variable

UNDEFINE

command to remove a variable

VERIFY

command to toggle the display of the substitution variables, both before and after SQL Developer replaces substitution variables with values