How to Simulate PHP's explode() Function in MySQL to Split Strings?

Split string in MySQL

There is no built-in function in MySQL similar to the PHP explode() function to split strings. However, with a little ingenuity, a similar effect can be achieved.

Create a custom explode function

To create a custom explode function, you can use the following syntax:

<code class="language-sql">CREATE FUNCTION SPLIT_STRING(str VARCHAR(255), delim VARCHAR(12), pos INT)
RETURNS VARCHAR(255)
RETURN REPLACE(SUBSTRING(SUBSTRING_INDEX(str, delim, pos),
       CHAR_LENGTH(SUBSTRING_INDEX(str, delim, pos-1)) + 1),
       delim, '');</code>

This function accepts three parameters: the string to split (str), the delimiter (delim), and the number of occurrences to return (pos).

Usage

To use a custom explode function, call it like this:

<code class="language-sql">SELECT SPLIT_STRING('apple, pear, melon', ',', 1);</code>

This query will return "apple" as the first occurrence of a comma separated string.

Example use case

In your specific use case, you want to search for sports results that are the same but in reverse order in different database records. You can use a custom explode function to split the fraction into individual numbers and compare:

<code class="language-sql">WHERE opponent1.date = opponent2.date
  AND SPLIT_STRING(opponent1.score, '-', 1) = SPLIT_STRING(opponent2.score, '-', 2)
  AND SPLIT_STRING(opponent1.score, '-', 2) = SPLIT_STRING(opponent2.score, '-', 1)</code>

This query will return match records with the same score but in reverse order.

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