FULL NAME TO FIRST, MIDDLE, LAST IN MYSQL

UPDATE student t
JOIN (
    SELECT
        id,
        first AS full_name,
        -- Extract first name (first part)
        SUBSTRING_INDEX(first, ' ', 1) AS f_name,
        -- Extract middle name (everything between first and last)
        CASE 
            WHEN LENGTH(first) - LENGTH(REPLACE(first, ' ', '')) >= 2 
            THEN SUBSTRING_INDEX(SUBSTRING_INDEX(first, ' ', 2), ' ', -1)
            ELSE ''
        END AS m_name,
        -- Extract last name (last part)
        SUBSTRING_INDEX(first, ' ', -1) AS l_name
    FROM student
) x ON t.id = x.id
SET
    t.first = x.f_name,
    t.middle = x.m_name,
    t.last = x.l_name;

Note : update your_table to required table name