MySQL：8.0.20 MySQL Community Server - GPL

隔離級別：RC

8版中本有performance.schema.data_locks 表，方便分析鎖問題

建立測試資料：

mysql> show create table t1\G
*************************** 1. row ***************************
       Table: t1
Create Table: CREATE TABLE `t1` (
  `id` int NOT NULL AUTO_INCREMENT,
  `od` int DEFAULT NULL,
  `name` varchar(
 
200) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `od` (`od`)
) ENGINE=InnoDB AUTO_INCREMENT=101 DEFAULT CHARSET=utf8
1 row in set (0.00 sec)

mysql> insert into t1(id,od,name) values(1,1,'a'),(2,2,'b'),(3,3,'c'),(4,4,'d'),(100,100,'fff');

1、insert 唯一鍵不衝突

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

mysql
 
> insert into t1(id,od,name) values(50,50,'def');
Query OK, 1 row affected (0.00 sec)

performance.schema.data_locks 表 查詢結果如下

2、insert into 主鍵衝突

mysql> begin;
Query OK, 0 rows affected (0.01 sec)

mysql
 
> insert into t1(id,od,name) values(4,4,'d');
ERROR 1062 (23000): Duplicate entry '4' for key 't1.PRIMARY'

3、insert into 唯一約束衝突

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

mysql> insert into t1(id,od,name) values(400,4,'d');
ERROR 1062 (23000): Duplicate entry '4' for key 't1.od'

4、replace into ... 主鍵/唯一約束衝突

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

mysql> replace into t1(id,od,name) values(4,4,'ddddd');
Query OK, 2 rows affected (0.00 sec)

5、replace into ... 唯一約束衝突

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

mysql> replace into t1(id,od,name) values(null,4,'ddddd');
Query OK, 2 rows affected (0.00 sec)

6、同一事務 delete / insert into 唯一約束