SELECT

Important Note: As of the current version, DiceDB does not support multiple databases. Therefore, the SELECT command is currently a dummy method and does not affect the database. It remains as a placeholder.

The SELECT command is used to switch the currently selected database for the current connection in DiceDB. By default, DiceDB starts with database 0, but it supports multiple databases, which can be accessed by using the SELECT command. This command is essential for managing data across different logical databases within a single DiceDB instance.

Syntax

SELECT index

Parameters

Parameter	Description	Type	Required
index	The zero-based index of the database to select. DiceDB databases are indexed starting from 0 up to a configurable maximum (default is 15, configurable via the databases configuration directive)	Integer	Yes

Return Value

Condition	Return Value
Command is successful	OK

Behaviour

When the SELECT command is issued, the current connection’s context is switched to the specified database. All subsequent commands will operate on the selected database until another SELECT command is issued or the connection is closed.

• Initial State: By default, the connection starts with database 0.
• Post-Command State: The connection will be associated with the specified database index.
• The number of databases is configurable in the DiceDB configuration file (DiceDB.conf) using the databases directive.
• Switching databases does not affect the data stored in other databases; it only changes the context for the current connection.
• The SELECT command is connection-specific. Different connections can operate on different databases simultaneously.

Errors

1. Invalid Database Index:

   • Error Message: (error) ERR DB index is out of range
   • Occurs when the specified database index exceeds the configured maximum (default 15)

2. Non-Integer Index:

   • Error Message: (error) ERR value is not an integer or out of range
   • Occurs when the provided index is not a valid integer

Example Usage

Switching to Database 1

127.0.0.1:7379> SELECT 1
OK

Switching Back to Default Database

127.0.0.1:7379> SELECT 0
OK

Invalid Database Index

Error Example: Invalid Database Index

127.0.0.1:7379> SELECT 16
(error) ERR DB index is out of range

Invalid Input Type

127.0.0.1:7379> SELECT one
(error) ERR value is not an integer or out of range

Notes

As mentioned at the beginning of this document, the current version of DiceDB does not support multiple databases. The SELECT command is implemented as a placeholder for future functionality. All operations, regardless of the SELECT command, will continue to operate on a single database space.