Re: Help with a not match

"David G. Johnston" <[email protected]> Fri, 9 Nov 2018 09:54:23 -0700
Newsgroups gmane.comp.db.postgresql.sql
Message-ID <CAKFQuwaSZyaiKpo1wfWWnuwfdYvqnM3ePjNxPXBt+o5TNUHEFA@mail.gmail.com>
On Fri, Nov 9, 2018 at 9:46 AM Campbell, Lance <[email protected]> wrote:
> Use case:
> I have a table I will call “tableA”.  It has two columns.  One column is an “id” that is an integer primary key.  The second field is a text field called “content”.
> In the “content” field there may or may not be this substring “/files/{id}/” .  Note that {id} represents the field id for that record.  I want to find any rows where content contains “/files/###/” where the ### does not match the id for the row.  Also note that the id could be 1 to five digits.  Also there could be good and bad substrings in the content field.
> Example where a row is fine:
> Id=123
> Content=”abc”
> Id=345
> Content=”abc files/345/ abc files/345/”
> Example where a rows are not good:
> Id=123
> Content=”abc files/456/”
> Id=123
> Content=”abc files/123/ abc files/456/”
> Could you please help me with the proper way to write this SQL statement?
> Select id from tableA where content like …

Personally I'd use a regular expression:

... WHERE content ~ '/' || id || '/';

It not obvious why your fourth example is not good - the pattern above
will see files/123/ and be happy.

David J.