ISNUMERIC

The ISNUMERIC function determines whether an expression evaluates to a valid numeric type, returning 1 if it is valid and 0 if it is not valid.

Syntax

ISNUMERIC (expression)

Remarks

The following table lists the data types of the evaluated expression for ISNUMERIC and the possible return values.

Data Type of Evaluated Expression	Returns
BIGINT, INT, SMALLINT, TINYINT, BIT, DECIMAL, NUMERIC, FLOAT, REAL, MONEY, SMALLMONEY	1
Any other data type	0

Example

SELECT Contact, Phone, ZipCode

WHERE ISNUMERIC (ZipCode) = 1

FROM /shared/examples/ds_orders/products products 

The above example returns the rows with zip code having valid numeric values.

Note: ISNUMERIC returns 1 for some characters that are not numbers, such as plus (+), minus (-), and valid currency symbols such as the dollar sign ($).