In Transact SQL, ISNUMERIC () function used to determine that whether an expression is valid numeric data type or not.
ISNUMERIC() returns INT value 0 OR 1.
Ø 0 for FALSE
Ø 1 for TRUE
Syntax: - ISNUMERIC (expression)
Important catches in ISNUMERIC () :- ISNUMERIC returns 1 for some characters that are not numbers, such as plus (+), minus (-), and valid currency symbols such as the dollar sign ($).
Examples:-
SELECT ISNUMERIC (123) --> 1
SELECT ISNUMERIC ('123') --> 1
SELECT ISNUMERIC ('abc') --> 0
SELECT ISNUMERIC ('123C') --> 0
SELECT ISNUMERIC ('12C3') --> 0
SELECT ISNUMERIC ('+') --> 1
SELECT ISNUMERIC ('-') --> 1
