XDEL

Introduction and Use Case(s)

XDEL is a command in Redis used to delete entries from a stream. This is useful in scenarios where you need to remove specific messages from a stream, such as purging outdated or irrelevant data.

Syntax

  1. XDEL key ID [ID ...]

Parameter Explanations

  • key: The name of the stream from which you want to delete entries.
  • ID: One or more entry IDs that specify which entries to delete from the stream.

Return Values

The XDEL command returns an integer representing the number of entries that were successfully removed.

Example

If you delete one entry:

  1. (integer) 1

If none of the specified entries exist:

  1. (integer) 0

Code Examples

  1. dragonfly> XADD mystream * field1 value1
  2. "1627812000000-0"
  3. dragonfly> XADD mystream * field2 value2
  4. "1627812001000-0"
  5. dragonfly> XLEN mystream
  6. (integer) 2
  7. dragonfly> XDEL mystream 1627812000000-0
  8. (integer) 1
  9. dragonfly> XLEN mystream
  10. (integer) 1
  11. dragonfly> XRANGE mystream - +
  12. 1) "1627812001000-0"
  13.    1) "field2"
  14.    2) "value2"

Best Practices

  • Ensure the entry ID exists before attempting to delete it.
  • Use XLEN to check the number of entries before and after deletion to confirm the operation’s success.

Common Mistakes

  • Trying to delete non-existent entry IDs will result in a return value of 0.
  • Deleting all entries this way doesn’t delete the stream itself; use DEL for that purpose.

FAQs

Does XDEL remove the stream if all entries are deleted?

No, XDEL only removes the specified entries. To remove the stream, use the DEL command.

Can I delete multiple entries at once with XDEL?

Yes, you can specify multiple entry IDs in a single XDEL command to delete multiple entries simultaneously.