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DiceDB

DEL

The DEL command in DiceDB is used to remove one or more keys from the database. If a given key does not exist, it is ignored. The command returns the number of keys that were removed.

Syntax

DEL key [key ...]

Parameters

  • key: The key(s) to be removed from the database. Multiple keys can be specified, separated by spaces.

Return Value

The DEL command returns an integer representing the number of keys that were removed.

  • Type: Integer
  • Description: The number of keys that were successfully removed.

Behaviour

When the DEL command is executed, DiceDB will attempt to remove the specified keys from the database. The command operates in the following manner:

  1. Key Existence Check: For each key specified, DiceDB checks if the key exists in the database.
  2. Key Removal: If a key exists, it is removed from the database.
  3. Count Removal: The command keeps a count of how many keys were successfully removed.
  4. Return Count: The total count of removed keys is returned as the result of the command.

Error Handling

The DEL command is generally robust and straightforward, but there are a few scenarios where errors might occur:

  1. Wrong Type of Argument: If the command is provided with an argument that is not a valid key (e.g., a non-string type), DiceDB will raise a syntax error.

    • Error Message: (error) ERR wrong number of arguments for 'del' command

  2. No Arguments Provided: If no keys are provided to the DEL command, DiceDB will raise a syntax error.

    • Error Message: (error) ERR wrong number of arguments for 'del' command

Example Usage

Single Key Deletion

Terminal window
127.0.0.1:7379> DEL mykey

Description: This command will attempt to delete the key mykey from the database. If mykey exists, it will be removed, and the command will return 1. If mykey does not exist, the command will return 0.

Multiple Keys Deletion

Terminal window
127.0.0.1:7379> DEL key1 key2 key3

Description: This command will attempt to delete the keys key1, key2, and key3 from the database. The return value will be the number of keys that were successfully removed. For example, if key1 and key3 exist but key2 does not, the command will return 2.

Example with Return Values

Terminal window
127.0.0.1:7379> SET key1 "value1"
127.0.0.1:7379> SET key2 "value2"
127.0.0.1:7379> SET key3 "value3"
127.0.0.1:7379> DEL key1 key2 key4

Description: In this example:

  • key1, key2, and key3 are set with some values.
  • The DEL command attempts to delete key1, key2, and key4.
  • Since key1 and key2 exist, they will be removed.
  • key4 does not exist, so it will be ignored.
  • The command will return 2, indicating that two keys were removed.