将正则表达式模式转换为 sql

Question

I have a SQL database that contains a table of emails. I would like to select all the emails that have characters from the regex pattern:

^[^ @]+@([^ @.]+\\.)+[^ @.]+$

I'm trying to write the request but I have mistakes. Can anyone help me?

Answer 1

You don't need a regular expression for the pattern you are specifying. You can use like :

where email like '%@%.%' and
      email not like '%@%@%' and    -- only one @
      email not like '%.%.%' and    -- only one .
      email not like '% %'          -- no space

The use of regular expressions depends on the database you are using (but like is SQL so it should work in all databases). Of course, if your (unspecified) database supports regular expression, you can still use them. If you do so, however, you might do some research because there are better regular expressions for email matching.

Answer 2

Here is the example to use RegEx in SQL query

SELECT * from table WHERE email REGEXP '^[^ @]+@([^ @.]+\.)+[^ @.]+$';

Let me know it works.

Answer 3

Thanks all this is the solution that worked for me:

WHERE email !~ '^[^ @]+@([^ @.]+.)+[^ @.]+$'