MSET

Introduction and Use Case(s)

The MSET command in Redis is used to set multiple key-value pairs in a single atomic operation. This command is particularly useful when you need to update several keys at once, ensuring that either all keys are updated or none are if an error occurs.

Syntax

  1. MSET key1 value1 [key2 value2 ...]

Parameter Explanations

  • key1, key2, …: The keys that you want to set.
  • value1, value2, …: The values corresponding to each key.

Each key must have a corresponding value and vice versa.

Return Values

MSET always returns OK since it will not raise any errors if provided with the correct number of arguments.

Code Examples

  1. dragonfly> MSET key1 "value1" key2 "value2" key3 "value3"
  2. "OK"
  3. dragonfly> GET key1
  4. "value1"
  5. dragonfly> GET key2
  6. "value2"
  7. dragonfly> GET key3
  8. "value3"

Best Practices

  • Ensure you provide an even number of arguments to MSET for proper key-value pairing.
  • Use MSET when multiple key updates are required simultaneously to maintain atomicity.

Common Mistakes

  • Providing an odd number of arguments will result in a syntax error since every key needs a corresponding value.

FAQs

What happens if one of the keys already exists?

MSET will overwrite the existing keys with the new values provided.

Is MSET an atomic operation?

Yes, MSET is atomic. All specified keys are set at once, ensuring consistency.