Hash Commands
HSET-&-HGET
Hash is Redis's native object type. Store user profiles, settings, and structured data without JSON serialization overhead.
You'll Learn
- HSET, HGET, HGETALL syntax
- When to use Hash vs String
- Partial updates with HINCRBY
- How Redimo renders Hash like a spreadsheet
Free Download
See Your Data, Not Terminal Text
Redimo visualizes every Redis data type beautifully. Edit inline, undo mistakes, stay safe in production.
1. What Is a Hash?
A Hash is a collection of field-value pairs under a single key. Think of it as a mini-database row, a JavaScript object, or a Python dictionary. It's Redis's native way to store structured data.
Unlike storing JSON in a String, Hash lets you read and write individual fields without touching the rest. This makes partial updates efficient and atomic - perfect for user profiles, session data, or any object with multiple properties.
Syntax
HSET key field value [field value ...]
HGET key field
HGETALL key
HDEL key field [field ...]
HINCRBY key field increment
HEXISTS key field
HKEYS key
HVALS key
HLEN keyHash Advantages
- • Update single fields atomically
- • No JSON parse/stringify overhead
- • Memory efficient for small objects
- • Increment numeric fields directly
Best Use Cases
- • User profiles and settings
- • Session metadata
- • Object caching with partial updates
- • Counters grouped by entity
2. The CLI Way (Hard Mode)
Reading a hash in CLI returns alternating field-value lines. With many fields, matching them becomes a mental exercise:
Creating and Reading a Hash
127.0.0.1:6379> HSET user:1001 name "John Doe" email "john@example.com" age 28 role "admin" created_at "2024-01-15" last_login "2024-12-20" login_count 47 premium true
(integer) 8
127.0.0.1:6379> HGETALL user:1001
1) "name"
2) "John Doe"
3) "email"
4) "john@example.com"
5) "age"
6) "28"
7) "role"
8) "admin"
9) "created_at"
10) "2024-01-15"
11) "last_login"
12) "2024-12-20"
13) "login_count"
14) "47"
15) "premium"
16) "true"Reading and Updating Fields
127.0.0.1:6379> HGET user:1001 email
"john@example.com"
127.0.0.1:6379> HGET user:1001 login_count
"47"
127.0.0.1:6379> HINCRBY user:1001 login_count 1
(integer) 48
127.0.0.1:6379> HMGET user:1001 name email role
1) "John Doe"
2) "john@example.com"
3) "admin"The Problem
HGETALL returns a flat list with alternating field-value pairs. With 20+ fields, you're counting lines to match fields to values. One miscount and you're reading the wrong data. And there's no visual structure to help you.
3. The Redimo Way (Smart Mode)
Redimo renders Hash data as an Excel-like grid. Each field is a row with its value clearly displayed. Click any cell to edit. No counting, no guessing, no mistakes.
What Redimo Does for Hashes:
- ●Spreadsheet View: Two-column layout with Field and Value. Instantly see all data without mental parsing.
- ●Inline Editing: Click any value to edit it directly. Changes are saved with a single HSET command.
- ●Add/Delete Fields: Buttons to add new fields or delete existing ones. No command typing required.
- ●Virtual Scrolling: Hash with 10,000+ fields? No problem. Virtual scrolling keeps the UI responsive.
- ●Field Search: Search within the hash to find specific fields quickly.
CLI Pain Points
- • Flat alternating list is confusing
- • Must count to match field-value pairs
- • No visual structure at all
- • Must use HGET for individual fields
- • Large hashes are impossible to scan
Redimo Solutions
- • Clear Field | Value table layout
- • Every pair on its own row
- • Click to edit any field
- • Add/delete buttons for fields
- • Virtual scrolling for large hashes
4. Hash vs JSON String
When should you use a Hash vs storing JSON in a String? Here's the decision guide:
| Criteria | Use Hash | Use JSON String |
|---|---|---|
| Partial updates | ✓ Update single fields | Read-modify-write entire JSON |
| Nested data | Only flat key-value | ✓ Deep nesting supported |
| Numeric operations | ✓ HINCRBY, HINCRBYFLOAT | Must parse and re-serialize |
| Memory (small) | ✓ ziplist encoding | Slightly more overhead |
| Arrays | Not directly supported | ✓ Native JSON arrays |
Rule of Thumb
Use Hash when you need to update individual fields frequently. Use JSON String when you always read/write the entire object, or when you have deeply nested structures.
5. Common Patterns
User Profile
# Create user profile
HSET user:1001 name "Jane Doe" email "jane@example.com" plan "pro" signup_date "2024-06-15"
# Update single field
HSET user:1001 plan "enterprise"
# Increment login count
HINCRBY user:1001 login_count 1
# Check if field exists
HEXISTS user:1001 premiumShopping Cart
# Add items to cart (field = product_id, value = quantity)
HSET cart:user:1001 product:123 2 product:456 1 product:789 3
# Update quantity
HINCRBY cart:user:1001 product:123 1
# Remove item
HDEL cart:user:1001 product:456
# Get all items
HGETALL cart:user:1001
# Count items in cart
HLEN cart:user:1001Feature Flags
# Set feature flags
HSET features:user:1001 dark_mode true beta_access true new_dashboard false
# Check single flag
HGET features:user:1001 beta_access
# Toggle flag
HSET features:user:1001 new_dashboard true
# Get all flags at once
HGETALL features:user:10016. Pro Tips
Valkey Compatibility
All Hash commands work identically in Valkey and Redis. Redimo auto-detects your server type. No code changes needed when switching.
Useful Hash Commands
# Get list length (field count)
HLEN user:1001
# Get all field names only
HKEYS user:1001
# Get all values only
HVALS user:1001
# Get multiple specific fields
HMGET user:1001 name email role
# Check if multiple fields exist
# (Redis 7.4+) HEXISTS returns count
HEXISTS user:1001 premium beta_tester
# Increment float value
HINCRBYFLOAT user:1001 balance 10.50
# Set only if field doesn't exist
HSETNX user:1001 created_at "2024-01-01"Redimo Bonus
Redimo uses native Redis commands (HSET, HDEL) instead of read-modify-write. This means your edits are atomic and won't conflict with other clients modifying the same hash.
Ready to Visualize?
Stop counting field-value pairs in your terminal.
Download Redimo and edit Hash data like a spreadsheet.