At some level, the SQL UPDATE statement is the union of the SQL INSERT and DELETE statements, because you must select rows to modify as well as specify how to modify them.

在某种程度上，SQL update语句是SQL INSERT和delete语句的联合，因为您必须选择要修改的行，还必须指定如何修改它们。

youdao

But in DB2, you must provide a value for NOT NULL columns in an INSERT statement when a default hasn't been defined.

但在DB 2中，如果未定义该值，则必须在insert语句中为NOT null列提供值。

youdao