Sam Grant Sam Grant - 1 month ago 6
MySQL Question

Mysql extract first letter of each word in a specific column

I want to create an acronym column in a table. I want to be grab the first letter of each word from a 'name' column, capitalize it, then concatenate all into an 'acronym' column.

Any easy way to grab first letters?

Answer

Here is an "improved" function, allowing to filter only wanted characters thanks to a regular expression.

  • function initials does the actual job, you have to specify the regular expression
  • function acronym does the job keeping Alpha-numeric characters only

(Use upper, lower or ucase functions on the output if necessary) .

delimiter $$
drop function if exists `initials`$$
CREATE FUNCTION `initials`(str text, expr text) RETURNS text CHARSET utf8
begin
    declare result text default '';
    declare buffer text default '';
    declare i int default 1;
    if(str is null) then
        return null;
    end if;
    set buffer = trim(str);
    while i <= length(buffer) do
        if substr(buffer, i, 1) regexp expr then
            set result = concat( result, substr( buffer, i, 1 ));
            set i = i + 1;
            while i <= length( buffer ) and substr(buffer, i, 1) regexp expr do
                set i = i + 1;
            end while;
            while i <= length( buffer ) and substr(buffer, i, 1) not regexp expr do
                set i = i + 1;
            end while;
        else
            set i = i + 1;
        end if;
    end while;
    return result;
end$$

drop function if exists `acronym`$$
CREATE FUNCTION `acronym`(str text) RETURNS text CHARSET utf8
begin
    declare result text default '';
    set result = initials( str, '[[:alnum:]]' );
    return result;
end$$
delimiter ;

Example1:

select acronym('Come Again? That Cant Help!');

Outputs:

CATCH

Example2:

select initials('Come Again? That Cant Help!', '[aeiou]');

Outputs:

oeAaaae