RENAME

The RENAME command in DiceDB is used to change the name of an existing key to a new name. If the new key name already exists, it will be overwritten. This command is useful for renaming keys in a DiceDB database without having to delete and recreate them.

Syntax

RENAME oldkey newkey

Parameters

Parameter	Description	Type	Required
oldkey	The current name of the key you want to rename. This key must exist in the DiceDB database.	String	Yes
newkey	The new name for the key. If a key with this name already exists, it will be overwritten.	String	Yes

Return values

Condition	Return Value
Command is successful	OK
oldkey does not exist	(error) ERR no such key
arguments not equal to 2	(error) ERR wrong number of arguments for 'rename' command

Behaviour

• The RENAME command renames an existing key (oldkey) to a new name (newkey).
• If newkey already exists, it will be overwritten by the value of oldkey.
• If oldkey does not exist, an error is returned.
• The operation is atomic, ensuring no other commands can interfere while it executes.
• If the source and destination keys are the same, the command will return OK without making changes.

Errors

1. Key does not exist:

   • Error Message: (error) ERR no such key
   • Occurs when the specified oldkey does not exist in the database.

2. Wrong number of arguments:

   • Error Message: (error) ERR wrong number of arguments for 'rename' command
   • Occurs if the command is not used with exactly two arguments.

Example Usage

Basic Example

Renaming a key from mykey to mynewkey

127.0.0.1:7379> SET mykey "Hello"
OK
127.0.0.1:7379> RENAME mykey mynewkey
OK
127.0.0.1:7379> GET mynewkey
"Hello"

Overwriting an Existing Key

Renaming key1 to key2 will overwrite key2:

127.0.0.1:7379> SET key1 "Value1"
OK
127.0.0.1:7379> SET key2 "Value2"
OK
127.0.0.1:7379> RENAME key1 key2
OK
127.0.0.1:7379> GET key2
"Value1"

Error Example: Non-Existent Key

Attempting to rename a non-existing key

127.0.0.1:7379> RENAME nonexistingkey newkey
(error) ERR no such key

Error Example: Incorrect Number of Arguments

Trying to rename with only one argument

127.0.0.1:7379> RENAME key1
(error) ERR wrong number of arguments for 'rename' command

Best Practices

• Check Key Existence: Before renaming a key, ensure that the oldkey exists to avoid errors.
• Atomic Operations: The RENAME command is atomic, meaning it is executed as a single, indivisible operation. This ensures that no other commands can interfere with the renaming process.
• Avoid Overwriting: Be cautious when renaming keys to names that already exist, as this will overwrite the existing key and its value.