Efficient ISNUMERIC() replacements on SQL Server?

Question

So I just spent 5 hours troubleshooting a problem which turned out to be due not only to the old unreliable ISNUMERIC but it looks like my problem only appears

Answer 1

How about implementing these two functions:

CREATE FUNCTION dbo.isReallyNumeric  
(  
    @num VARCHAR(64)  
)  
RETURNS BIT  
BEGIN  
    IF LEFT(@num, 1) = '-'  
        SET @num = SUBSTRING(@num, 2, LEN(@num))  

    DECLARE @pos TINYINT  

    SET @pos = 1 + LEN(@num) - CHARINDEX('.', REVERSE(@num))  

    RETURN CASE  
    WHEN PATINDEX('%[^0-9.-]%', @num) = 0  
        AND @num NOT IN ('.', '-', '+', '^') 
        AND LEN(@num)>0  
        AND @num NOT LIKE '%-%' 
        AND  
        (  
            ((@pos = LEN(@num)+1)  
            OR @pos = CHARINDEX('.', @num))  
        )  
    THEN  
        1  
    ELSE  
    0  
    END  
END  
GO  

CREATE FUNCTION dbo.isReallyInteger  
(  
    @num VARCHAR(64)  
)  
RETURNS BIT  
BEGIN  
    IF LEFT(@num, 1) = '-'  
        SET @num = SUBSTRING(@num, 2, LEN(@num))  

    RETURN CASE  
    WHEN PATINDEX('%[^0-9-]%', @num) = 0  
        AND CHARINDEX('-', @num) <= 1  
        AND @num NOT IN ('.', '-', '+', '^') 
        AND LEN(@num)>0  
        AND @num NOT LIKE '%-%' 
    THEN  
        1  
    ELSE  
        0  
    END  
END  
GO

Original Source