In MySQL, you can use the ELT() function to return a list item at a given position in the list.

The syntax goes like this:

ELT(N,str1,str2,str3,...)

Where N is the position of the item you want to return, and str1,str2,str3,... is the list.

Example

Here’s an example:

SELECT ELT(3, 'Marge', 'Homer', 'Bart') AS 'Who is at 3?';

Result:

+--------------+ | Who is at 3? | +--------------+ | Bart | +--------------+ 

In this case we specify that we want to return the 3rd item in the list (because the first argument is 3) . And in this case the list is 'Marge', 'Homer', 'Bart', so the 3rd item is Bart.

Numbers

Here’s an example containing numbers:

SELECT ELT(3, 9, 8, 7) AS 'The 3rd item is...';

Result:

+--------------------+ | The 3rd item is... | +--------------------+ | 7 | +--------------------+ 

Database Example

Here’s an example where I match up the results of a database query to a list of values:

SELECT GenreId, ELT(GenreId, 'Rock', 'Jazz', 'Country') AS Genre FROM Genres; 

Result:

+---------+---------+ | GenreId | Genre | +---------+---------+ | 1 | Rock | | 2 | Jazz | | 3 | Country | | 4 | NULL | | 5 | NULL | | 6 | NULL | | 7 | NULL | | 8 | NULL | +---------+---------+ 

In this case there were more results than I included as parameters, therefore, those results are NULL.

The ELT() function is a complement to the FIELD() function, that allows you to find the index position of a given item in a list.