Determines whether an expression is a valid numeric type.
Syntax
ISNUMERIC ( expression )
Remarks
ISNUMERIC returns 1 when the input expression evaluates to a valid numeric data type; otherwise it returns 0. Valid numeric data types include the following:
Example
USE AdventureWorks2012;
GO
SELECT City, PostalCode
FROM Person.Address
WHERE ISNUMERIC(PostalCode)<> 1;
GO
Note
For, SQL Server 2012+ use TRY_PARSE instead as ISNUMERIC is treating as numbers some not numeric values:
SELECT ISNUMERIC('123') as '123'
,ISNUMERIC('abc') as 'abc'
,ISNUMERIC('-') as '-'
,ISNUMERIC('+') as '+'
,ISNUMERIC('$') as '$'
,ISNUMERIC('.') as '.'
,ISNUMERIC(',') as ','
,ISNUMERIC('\') as '\'
