INSERT INTO table2 (ID, col1, col2, col3, col4)
SELECT
t1.id
, substring_index(t1.col1,';',1)
, substring_index(t1.col1,';',2)
, substring_index(t1.col1,';',3)
, substring_index(t1.col1,';',4)
FROM table1 t1
参照: http://dev.mysql .com / doc / refman / 5.0 / en / string-functions.html#function_substring-index