MySQL 9.1 Release Notes
Normally, errors occur for data-change statements (such as
INSERT or
UPDATE) that would violate
primary-key, unique-key, or foreign-key constraints. If you
are using a transactional storage engine such as
InnoDB, MySQL automatically rolls back the
statement. If you are using a nontransactional storage engine,
MySQL stops processing the statement at the row for which the
error occurred and leaves any remaining rows unprocessed.
MySQL supports an IGNORE keyword for
INSERT,
UPDATE, and so forth. If you
use it, MySQL ignores primary-key or unique-key violations and
continues processing with the next row. See the section for
the statement that you are using (Section 15.2.7, “INSERT Statement”,
Section 15.2.17, “UPDATE Statement”, and so forth).
You can get information about the number of rows actually
inserted or updated with the
mysql_info() C API function.
You can also use the SHOW
WARNINGS statement. See
mysql_info(), and
Section 15.7.7.41, “SHOW WARNINGS Statement”.
InnoDB and NDB tables
support foreign keys. See
Section 1.7.3.2, “FOREIGN KEY Constraints”.