HGETALL for all fields in Redis - Step-by-Step Execution

Concept Flow - HGETALL for all fields

Start: Have a Redis hash key

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Call HGETALL command

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Redis fetches all fields and values

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Return all fields and values as list

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Client receives full hash data

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End

The HGETALL command fetches all fields and their values from a Redis hash key and returns them as a list.

Execution Sample

Redis

HSET user:1 name "Alice" age "30" city "NY"
HGETALL user:1

Set multiple fields in a hash and then get all fields and values from that hash.

Execution Table

Step	Command	Action	Result
1	HSET user:1 name "Alice" age "30" city "NY"	Store fields and values in hash 'user:1'	3
2	HGETALL user:1	Fetch all fields and values from 'user:1'	["name", "Alice", "age", "30", "city", "NY"]
3	End	No more commands	Execution stops

💡 All fields and values retrieved; no more commands to execute.

Variable Tracker

Variable	Start	After HSET	After HGETALL	Final
user:1 hash	empty	{"name":"Alice", "age":"30", "city":"NY"}	same	same
HGETALL output	none	none	["name", "Alice", "age", "30", "city", "NY"]	same

Key Moments - 2 Insights

Why does HGETALL return a flat list instead of a dictionary?

HGETALL returns a flat list alternating fields and values as Redis protocol uses this format; you can convert it to a dictionary in your client code. See execution_table row 2.

What happens if the hash key does not exist?

HGETALL returns an empty list if the hash key does not exist, meaning no fields or values are found. This is not shown here but is standard behavior.

Visual Quiz - 3 Questions

Look at the execution table, what is the output of the HGETALL command at step 2?

A ["name", "Alice", "age", "30", "city", "NY"]

B {"name": "Alice", "age": "30", "city": "NY"}

C ["user:1"]

D null

💡 Hint

Check the 'Result' column in execution_table row 2.

At which step does the Redis hash 'user:1' get populated with fields?

A Step 2

B Step 1

C Step 3

D Before Step 1

💡 Hint

Look at the 'Action' column in execution_table row 1.

If the hash 'user:1' had no fields, what would HGETALL return at step 2?

A An error message

B null

C An empty list []

D A list with one empty string

💡 Hint

Recall Redis behavior for non-existing or empty hashes; see key_moments section.

Concept Snapshot

HGETALL key
- Retrieves all fields and values from a Redis hash.
- Returns a flat list: [field1, value1, field2, value2, ...].
- If key missing, returns empty list.
- Use client code to convert list to dictionary if needed.

Full Transcript

This visual execution shows how the Redis HGETALL command works. First, we set multiple fields in a hash key 'user:1' using HSET. Then, we call HGETALL on 'user:1' to get all fields and values. Redis returns a flat list alternating fields and values. The hash remains unchanged after HGETALL. If the hash did not exist, HGETALL would return an empty list. This helps you get all data stored in a hash at once.