|Oracle® Database PL/SQL User's Guide and Reference
10g Release 2 (10.2)
|PDF · Mobi · ePub|
A literal is an explicit numeric, character, string, or Boolean value not represented by an identifier. The numeric literal 135 and the string literal
'hello world' are examples. For more information, see "Literals".
numeric literal ::=
integer literal ::=
real number literal ::=
character literal ::=
string literal ::=
boolean literal ::=
A member of the PL/SQL character set. For more information, see "Character Sets and Lexical Units".
One of the numerals 0 .. 9.
TRUE, FALSE, NULL
A predefined Boolean value.
Integer and real numeric literals can be used in arithmetic expressions. Numeric literals must be separated by punctuation. Spaces can be used in addition to the punctuation. For additional information, see "Numeric Literals".
A character literal is an individual character enclosed by single quotes (apostrophes). Character literals include all the printable characters in the PL/SQL character set: letters, numerals, spaces, and special symbols. PL/SQL is case sensitive within character literals. For example, PL/SQL considers the literals
'q' to be different. For additional information, see "Character Literals".
A string literal is a sequence of zero or more characters enclosed by single quotes. The null string (
'') contains zero characters. A string literal can hold up to 32,767 characters. PL/SQL is case sensitive within string literals. For example, PL/SQL considers the literals
'White' to be different.
To represent an apostrophe within a string, enter two single quotes instead of one. For literals where doubling the quotes is inconvenient or hard to read, you can designate an escape character using the notation
'. This escape character must not occur anywhere else inside the string.
Trailing blanks are significant within string literals, so
'abc ' are different. Trailing blanks in a string literal are not trimmed during PL/SQL processing, although they are trimmed if you insert that value into a table column of type
CHAR. For additional information, including
NCHAR string literals, see "String Literals".
FALSE cannot be inserted into a database column. For additional information, see "BOOLEAN Literals".
Several examples of numeric literals are:
25 6.34 7E2 25e-03 .1 1. +17 -4.4 -4.5D -4.6F
Several examples of character literals are:
'H' '&' ' ' '9' ']' 'g'
Several examples of string literals are:
'Don''t leave until you''re ready and I''m ready.'
q'#Don't leave until you're ready and I'm ready.#'
For examples, see the following: