How can we use nested transactions allowed in MySQL?

We can allow multiple transactions with the help of START command and SAVEPOINT. Let us create a table with the help of CREATE command.

Creating a table

mysql> CREATE table transactionDemo
-> (
-> id int auto_increment,
-> primary key(id)
-> );
Query OK, 0 rows affected (0.76 sec)

After that, I will begin a transaction with the help of START command −

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

After that, I am inserting the following record with the help of INSERT command −

mysql> INSERT into transactionDemo values();
Query OK, 1 row affected (0.04 sec)

We can display a record with the help of SELECT statement, which is as follows −

mysql> SELECT *from transactionDemo;

The following is the output

+----+
| id |
+----+
| 1  |
+----+
1 row in set (0.00 sec)

After that, I am saving this query with the help of SAVEPOINT. The query is as follows −

mysql> SAVEPOINT t2;

mysql> INSERT into transactionDemo values();
Query OK, 1 row affected (0.00 sec)

Display all the records with the help of SELECT command −

mysql> SELECT *from transactionDemo;

The following is the output

+----+
| id |
+----+
| 1  |
| 2  |
+----+
2 rows in set (0.00 sec)

Now, we can rollback the first transaction −

mysql> ROLLBACK TO t2;
Query OK, 0 rows affected (0.03 sec)

Now, we can display the transaction saved previously −

mysql> SELECT * from transactionDemo;

The following is the output

+----+
| id |
+----+
| 1  |
+----+
1 row in set (0.00 sec)

Ankith Reddy

Updated on: 2020-06-25T08:11:48+05:30

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