JSON.TYPE

The JSON.TYPE command allows you to work with JSON data structures in DiceDB. This command is used to determine the type of value stored at a specified path within a JSON document.

Syntax

JSON.TYPE <key> <path>

Parameters

Key	Description	Example	Required
key	The key under which the JSON document is stored.	`user:1001`	yes
path	The JSONPath expression that specifies the location within the JSON. The default path is the root($)	`$.address.city`	yes

Return Value

Condition	Value
Value is null	`null`
Value is a boolean	`boolean`
Value is an integer or float	`number`
Value is a string	`string`
Value is an array	`array`
Value is an object	`object`

Type

String
Description: The type of the value at the specified path. Possible return values include:
- null
- boolean
- number
- string
- array
- object
Example: string

Behaviour

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

Retrieve the JSON document stored at the specified key.
Navigate to the specified path within the JSON document.
Determine the type of the value located at that path.
Return the type as a string.

If the path does not exist within the JSON document, the command will return null.

Error Handling

Key Does Not Exist

Error: (nil)
Description: If the specified key does not exist in the DiceDB database, the command will return nil.

Invalid JSONPath

Error: ERR wrong number of arguments for 'json.type' command
Description: If the provided JSONPath is invalid or malformed, DiceDB will return an error indicating that the number of arguments is incorrect.

Non-JSON Data

Error: WRONGTYPE Operation against a key holding the wrong kind of value
Description: If the key exists but does not hold a JSON document, DiceDB will return an error indicating that the operation is against a key holding the wrong kind of value.

Example Usage

Basic Usage

127.0.0.1:7379> JSON.SET user:1001 $ '{"name": "John", "age": 30, "address": {"city": "New York", "zip": "10001"}}'
OK
127.0.0.1:7379> JSON.TYPE user:1001 $.name
"string"
127.0.0.1:7379> JSON.TYPE user:1001 $.age
"number"
127.0.0.1:7379> JSON.TYPE user:1001 $.address
"object"
127.0.0.1:7379> JSON.TYPE user:1001 $.address.city
"string"

Non-Existent Path

127.0.0.1:7379> JSON.TYPE user:1001 $.nonexistent
(empty array)

Key Does Not Exist

127.0.0.1:7379> JSON.TYPE user:9999 $.name
(nil)

Invalid JSONPath

127.0.0.1:7379> JSON.TYPE user:1001 $..name
"string"

Non-JSON Data

127.0.0.1:7379> SET mykey "This is a string"
OK
127.0.0.1:7379> JSON.TYPE mykey $
(error) ERROR Existing key has wrong Dice type