$atomic/$atOnce

Allows the actions in the REST request to be in a transaction. If there are no errors, the transaction is validated. Otherwise, the transaction is cancelled.

Description​

When you have multiple actions together, you can use $atomic/$atOnce to make sure that none of the actions are completed if one of them fails. You can use either $atomic or $atOnce.

Example​

We call the following REST request in a transaction.

POST /rest/Employee?$method=update&$atomic=true

POST data:

[
{
"__KEY":"200",
"firstname":"John"
},
{
"__KEY":"201",
"firstname":"Harry"
}
]

We get the following error in the second entity and therefore the first entity is not saved either:

{
"__STATUS":{
"success":true
},
"__KEY":"200",
"__STAMP":1,
"uri":"/rest/Employee(200)",
"__TIMESTAMP":"!!2020年04月03日!!",
"ID":200,
"firstname":"John",
"lastname":"Keeling",
"isWoman":false,
"numberOfKids":2,
"addressID":200,
"gender":false,
"address":{
"__deferred":{
"uri":"/rest/Address(200)",
"__KEY":"200"
}
},
"__ERROR":[
{
"message":"Cannot find entity with \"201\" key in the \"Employee\" dataclass",
"componentSignature":"dbmg",
"errCode":1542
}
]
}

Even though the salary for the first entity has a value of 45000, this value was not saved to the server and the timestamp (__STAMP) was not modified either. If we reload the entity, we will see the previous value.