The SUBSTRING_INDEX helps in extracting a part of the given string from the beginning to the match in the index.

Query:

SELECT SUBSTRING_INDEX('MySQL Database', 'a', 2) AS SUBSTRING_INDEX;

Here, the output will be from the beginning of the text “MySQL Database” until the second instance of the text ‘a’. The second instance is identified by the last argument. In this case, it has a value 2.

Sample Output:

+---------------------+| SUBSTRING_INDEX     |+---------------------+| MySQL Dat           |+---------------------+

If the query was modified as below:

Query: SELECT SUBSTRING_INDEX(‘MySQL Database’, ‘a’, 5) AS SUBSTRING_INDEX;

The expectation is that the text ‘a’ will be searched for the 5th occurrence and the values from the beginning to the 5th occurrence will be the output.

Here, we can see that the complete text is displayed, since the 5th index of ‘a’ does not exist.

+---------------------+| SUBSTRING_INDEX     |+---------------------+| MySQL Database      |+---------------------+