Executes all commands in a transaction if conditions match.
EXEC [<IFEQ key value | IFNE key value | NX nonexisting-key | XX existing-key>…]
Executes all previously queued commands in a transaction and restores the connection state to normal.
When using WATCH, EXEC will execute commands only if the watched keys were not modified, allowing for a check-and-set mechanism.
One of the following:
Array reply: each element being the reply to each of the commands in the atomic transaction.
Nil reply: the transaction was aborted because a WATCHed key was touched.
One of the following:
Array reply: each element being the reply to each of the commands in the atomic transaction.
Null reply: the transaction was aborted because a WATCHed key was touched.
O(N) for N conditions, plus the complexity of commands in the transaction
@slow @transaction
IFEQ, IFNE, NX, and XX options.