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BEGIN
Commits any existing open transaction on the current connection and starts a new transaction.
Syntax
START TRANSACTION | BEGIN [WORK]
Remarks
- This command must be run on the master aggregator or a child aggregator node (see Node Requirements for MemSQL Commands.
- If the transaction is successful, execute the COMMIT command to commit the changes; if the transaction is unsuccessful or needs to be reverted, then execute the ROLLBACK command to revert the changes.
Example
For this example, consider the following Employee
table:
ID | Name |
---|---|
30 | Jim |
20 | Rob |
40 | Rick |
BEGIN;
UPDATE Employee SET Name = "John" WHERE ID = 300;
****
Query OK, 0 rows affected (0.00 sec)
Rows matched: 0 Changed: 0 Warnings: 0
Run the SELECT
query to verify if the UPDATE
is correct:
SELECT * FROM Employee;
****
+------+-------+
| ID | Name |
+------+-------+
| 30 | Jim |
| 20 | Rob |
| 40 | Rick |
+------+-------+
Run ROLLBACK
since there were no matching results for the ID
and the UPDATE
was not successful.
ROLLBACK;
Note: Before the user runs COMMIT
or ROLLBACK
, only that user can see the updates made after BEGIN
was run.