Final answer:
To remove non numeric characters in SQL, use regular expressions with functions like REPLACE or REGEXP_REPLACE, or create a user-defined function to iterate through individual characters and filter out non-numeric ones.
Step-by-step explanation:
To remove non numeric characters in SQL, you can make use of regular expressions and the REPLACE function, or a similar string manipulation function available in your SQL database system. For databases such as MySQL, you might not have direct regular expression replace functionality. Instead, you will have to create a user-defined function or use a combination of string functions like TRANSLATE, REGEXP_REPLACE (if using PostgreSQL or Oracle), or a loop to filter out non-numeric characters.
SELECT REGEXP_REPLACE(your_column, '\\D', '', 'g') FROM your_table; This would remove all non-numeric characters from the column 'your_column' in the table 'your_table' and return only the numeric characters.