How to handle PDO transactions with possible duplicate entries

What happens if I commit a pdo transaction where one or more entries are duplicates 开发者_开发问答of already existing primary keys? Will the transaction insert all of the none duplicates or roll back?

If it is the latter, how can I prevent the rollback?

You won't be able to commit such transaction, because you won't be able to insert such rows in the first place.

See below In MySQL console #1 we do this:

mysql> USE TEST;
Database changed
mysql> CREATE TABLE trTest(ID INT UNSIGNED PRIMARY KEY) ENGINE = InnoDB;
Query OK, 0 rows affected (0.46 sec)

mysql> START TRANSACTION;
Query OK, 0 rows affected (0.00 sec)

mysql> INSERT INTO trTest VALUES (1);
Query OK, 1 row affected (0.00 sec)

Then in console #2 we try:

mysql> USE TEST;
Database changed
mysql> START TRANSACTION;

Query OK, 0 rows affected (0.00 sec)
mysql> INSERT INTO trTest VALUES (1);

The prompt will not return here and the session will hang for a while until...

ERROR 1205 (HY000): Lock wait timeout exceeded; try restarting transaction