Is there a difference between the two queries? Are both correct?

SET price = (SELECT buyPrice FROM products WHERE productCode = product);

SELECT buyPrice INTO price FROM products WHERE productCode = product;

CodePudding user response：

Both are correct.

With the SET syntax, you can only set one variable at a time, so the SELECT query must have only one expression in its select-list.

With the SELECT INTO syntax, you can set multiple variables. For example:

SELECT buyPrice, lastUpdated INTO price, latest FROM products ...