How to get the numeric part from a string using T-SQL?

Question

I have the following string.

Input
--------------
2030031469-NAI 

To get the numeric part, I am using the following script

Answer 1

In case your string start with alphabet and end with number like ERT-123

you can use this query:

 (select  substring(@str,patindex('%[0-9]%', @str),len(@str)))

Answer 2

To extract number from an unformatted string

DECLARE @Text NVARCHAR(100)= 'extract only 23124R integer @#%%'
SELECT SUBSTRING(@Text, PATINDEX('%[0-9]%',@Text), PATINDEX('%[^0-9]%',SUBSTRING(@Text, PATINDEX('%[0-9]%',@Text), LEN(@Text)))-1) [ONLY_INT]

Answer 3

select left(@str, patindex('%[^0-9]%', @str+'.') - 1)

Answer 4

Please check with this, i used in my project for extracting phone numbers

 CREATE Function [dbo].[RemoveNonNumericCharacters](@Temp VarChar(1000))
    Returns VarChar(1000)
    AS
    Begin

        While PatIndex('%[^0-9]%', @Temp) > 0
            Set @Temp = Stuff(@Temp, PatIndex('%[^0-9]%', @Temp), 1, '')

        Return @TEmp
    End