php - MYSQL select a piece of a string and order by that piece

Question

I have a field with this kind of info "web-1/1.,web-2/2.,web-3/3.,web-4/4.,web-5/5.". Other registers could have different values like "web-1/4.,web-2/5.,web-3/1.,web-4/2.,web-5/3."

I want to select and order by lets say web-2/? would be web-2/1, web-2/2, web-2/3 and so on all fields that contain web-2 and order by the last number

I want to create a featured properties script different websites and specify feature number. Different properties, different websites different order

Answer 1

I would suggest that you look at the MySQL String Functions and more specifically the SUBSTRING_INDEX function. The reason I suggest this one over SUBSTRING is because the number before or after the slash might be more than a single number which would make the length of the first and/or second parts vary.

Example:

SELECT   `info`,
         SUBSTRING_INDEX(`info`, '/', 1) AS `first_part`,
         SUBSTRING_INDEX(`info`, '/', -1) AS `second_part`
FROM     `table`
ORDER BY `first_part` ASC,
         `second_part` ASC;

Result:

Additional Example

In this example, I'm using CAST to convert the second part into an unsigned integer just in case it contains additional characters such as symbols or letters. In other words, the second part of "web-4/15." would be "15" and the second part of "web-4/15****" would also be "15".

SELECT   `info`,
          SUBSTRING_INDEX(`info`, '/', 1) AS `first_part`,
          CAST(SUBSTRING_INDEX(`info`, '/', -1) AS UNSIGNED) `second_part`
FROM     `table`
ORDER BY `first_part` ASC,
         `second_part` ASC;