update join

gistfile1.txt

UPDATE t_product
JOIN r_product_class on t_product.id = r_product_class.product_id
JOIN t_class on t_class.id = r_product_class.class_id
SET t_product.school_id = t_class.school_company_id;

UPDATE t_product_template
JOIN r_product_class on t_product_template.product_id = r_product_class.product_id
JOIN t_class on t_class.id = r_product_class.class_id
SET t_product_template.school_id = t_class.school_company_id;

INSERT INTO table2 (column1, column2, column3, ...)
SELECT column1, column2, column3, ...
FROM table1
WHERE condition;