Name
lt , lte , gt , gte , equ , neq — comparison functions
Synopsis
lt
(
|
in arg1 any , |
in
arg2
any
); |
lte
(
|
in arg1 any , |
in
arg2
any
); |
gt
(
|
in arg1 any , |
in
arg2
any
); |
gte
(
|
in arg1 any , |
in
arg2
any
); |
equ
(
|
arg1 any , |
arg2
any
); |
neq
(
|
in arg1 any , |
in
arg2
any
); |
Description
These functions return 1 if their first argument is less than (lt), less than or equivalent (lte), greater than (gt), greater than or equivalent (gte), equivalent (equ), or not equivalent (neq) to the second argument, respectively. If the arguments are not of the same type, then an appropriate type coercion is done for them before comparison.
These functions correspond to SQL query operators <, <=, >,
>=, = and <> and are needed because the SQL syntax does not
allow these operators to be used on the left side of
FROM
keyword in a SELECT
statement.
Parameters
arg1
,
arg2
integer , float , double precision , varchar or NULL .
Return Values
An integer value of 1 or 0 is returned.
Examples
Example 24.101. Simple Example
lt('pata','pato') -> 1 (Yes, 'pata' is less than 'pato')
gt('barbar','bar') -> 1 (Yes, 'barbar' is greater than 'bar')
equ(17,17) -> 1 (seventeen is seventeen)
equ(17,17.0) -> 1 (regardless of number format)
equ(atof('17.0'),17.0)) -> 1 (as it seems be)
equ(atof('17.1'),17.1)) -> 0 (But not always! Beware!)
gte(1234,NULL) -> 0 (No, 1234 is not "greater"
than or equal to NULL)
lt(1234,NULL) -> 1 (Instead, it is "less" than NULL)