Command: MAP.GET

Overview

The MAP.GET command allows users to retrieve values from a stored map object in the database. The user can either fetch the entire map stored at a given key or a specific field value inside the map using an optional mapKey .

Command Name

MAP.GET

Description

The command fetches structured JSON data stored as a map in the database. It can return:

  • The full map (when only the key is provided)

  • A single value from the map (when both key and mapKey are provided)

This is especially useful for structured entities like:

  • User profiles

  • Device settings

  • Application configurations

  • Metadata fields

Use Cases

Scenario Description
View all devices of a user Retrieve a list of all registered devices for a user using their user key
Get config detail Fetch only a specific field (like batteryLevel ) from a nested map
Debug map contents Quickly inspect what values are stored under a given key

Syntax 

  MAP.GET <key> [<mapKey>]

Arguments

Argument Required Description
<key> Yes The top-level key identifying the stored map
[mapKey] No A specific key within the stored map to retrieve its corresponding value

Permissions

  • Requires read access to the provided key.

  • No special privileges required beyond standard user-level access.

Examples

Example 1: Retrieve full map

Input:

  localhost:9219> MAP.GET user-001:devices

Output:

  Ok {
  "device-663abc5352": {
    "batteryLevel": "75%",
    "deviceName": "iPhone 14 Pro",
    "osVersion": "iOS 16"
  },
  "device-6d6f6sa66d": {
    "batteryLevel": "85%",
    "deviceName": "Pixel 7 Pro",
    "osVersion": "Android 14"
  }
}
Example 2: Retrieve value by map key

Input:

  localhost:9219> MAP.GET user-001:devices device-663abc5352

Output:

  Ok {
  "batteryLevel": "75%",
  "deviceName": "iPhone 14 Pro",
  "osVersion": "iOS 16"
}
Example 3: Retrieve a non-existent map key

Input:

  localhost:9219> MAP.GET user-001:devices device-nonexistent

Output:

  Ok ""

Behavior on Error

Error Case Message
Too many arguments (>2) InvalidArgsError: More than 2 args not supported, Supported args Key or key and mapKey

Notes

  • The command does not return an error if the mapKey is not found. It returns an empty string ( "" ).