Literals
String Literal
A string literal is enclosed in single quotes. To represent a single quote within a literal, use two single quotes; for example,
'literal''s'
. String literals use the Unicode character encoding. String literals are case sensitive. The server has a limit of 32,767 string literals in a selector string.
Exact Numeric Literal
An exact numeric literal is a numeric value without a decimal point, such as
57
,
-957
, and
+62
; numbers of
long
are supported.
Approximate Numeric Literal
An approximate numeric literal is a numeric value with a decimal point (such as
7.
,
-95.7
, and
+6.2
), or a numeric value in scientific notation (such as
7E.3
and
-57.9E2
); numbers in the range of
double
are supported. Approximate literals use floating-point literal syntax of the Java programming language.
Boolean Literal
The boolean literals are
TRUE
and
FALSE
(case insensitive).
Internal computations of expression values use a 3-value boolean logic similar to SQL. However, the final value of an expression is always either
TRUE
or
FALSE
, but never
UNKNOWN
.