Redis transactions can execute multiple commands at once, with the following two important guarantees:
The transaction is a separate isolated operation: all commands in the transaction are serialized and executed sequentially. During the execution of the transaction, it will not be interrupted by command requests sent by other clients.
A transaction is an atomic operation: either all commands in the transaction are executed, or none of them are executed.
A transaction will go through the following three stages from inception to execution:
- Start the business.
- Order to join the team.
- Perform affairs.
Example The
following is an example of a transaction. It first starts a transaction with MULTI, then enqueues multiple commands into the transaction, and finally triggers the transaction by the EXEC command, and executes all the commands in the transaction together:
127.0.0.1:6379> multi
OK
127.0.0.1:6379> set username lihaitao
QUEUED
127.0.0.1:6379> get username
QUEUED
127.0.0.1:6379> sadd fruit "apple" "banana" "orange"
QUEUED
127.0.0.1:6379> smembers fruit
QUEUED
127.0.0.1:6379> exec
1) OK
2) "lihaitao"
3) (integer) 3
4) 1) "apple"
2) "banana"
3) "orange"
127.0.0.1:6379>
Redis transaction commands The
following table lists the redis transaction related commands:
1 DISCARD cancels the transaction and abandons the execution of all commands in the transaction block.
127.0.0.1:6379> multi
OK
127.0.0.1:6379> set username lihaitao
QUEUED
127.0.0.1:6379> discard
OK
127.0.0.1:6379> exec
(error) ERR EXEC without MULTI
127.0.0.1:6379>
2 EXEC executes all commands in the transaction block.
3 MULTI marks the beginning of a transaction block.
4 UNWATCH cancels the monitoring of all keys by the WATCH command.
5 WATCH key [key …] Monitor one (or more) key. If this (or these) keys are changed by other commands before the transaction is executed, the transaction will be interrupted.
