JSON.MSET

The JSON.MSET command in DiceDB is used to set multiple JSON values at once. This command is particularly useful when you need to update several keys with JSON data in a single atomic operation, ensuring that all updates are applied together.

Parameters

Parameter	Description	Type	Required
key	The key where the JSON value will be set.	String	Yes
json	The JSON value to be set at the specified key.	String	Yes
...	Additional key-value pairs can be provided as needed.

The JSON.MSET command requires an even number of arguments. The arguments are provided in pairs, where each pair consists of a key and a JSON value.

Return Value

Condition	Return Value
Success	OK
Error in Syntax or Wrong key type	Error

Behaviour

When the JSON.MSET command is executed, DiceDB will:

1. Validate that the number of arguments is even.
2. Validate that each JSON value is a valid JSON string.
3. Set each key to its corresponding JSON value in an atomic operation.
4. Return OK if all operations are successful.

If any of the validations fail, the command will not set any of the keys, ensuring atomicity.

Error Handling

The JSON.MSET command can raise errors in the following scenarios:

1. Wrong number of arguments: If the number of arguments is not even, DiceDB will return an error.

   • Error Message: ERR wrong number of arguments for 'JSON.MSET' command

2. Invalid JSON: If any of the provided JSON values are not valid JSON strings, DiceDB will return an error.

   • Error Message: ERR invalid JSON string

3. Other DiceDB errors: Any other standard DiceDB errors that might occur during the execution of the command.

Example Usage

Setting Multiple JSON Values

127.0.0.1:7379> JSON.MSET user:1 '{"name": "Alice", "age": 30}' user:2 '{"name": "Bob", "age": 25}'
OK

In this example, two keys (user:1 and user:2) are set with their respective JSON values. The command returns OK indicating that both key-value pairs were successfully set.

Error: Odd Number of Arguments

127.0.0.1:7379> JSON.MSET user:1 '{"name": "Alice", "age": 30}' user:2
(error) ERR wrong number of arguments for 'JSON.MSET' command

In this example, the command fails because the number of arguments is odd. DiceDB returns an error indicating the wrong number of arguments.

Error: Invalid JSON

127.0.0.1:7379> JSON.MSET user:1 '{"name": "Alice", "age": 30}' user:2 '{name: "Bob", age: 25}'
(error) ERR invalid JSON string

In this example, the command fails because the JSON value for user:2 is not a valid JSON string. DiceDB returns an error indicating the invalid JSON string.