Allowing selecting Redis database

[rpj]

Need to add the ability to chose a Redis database number.

Simplest implementation would be to just add a SELECT command implementation that the consumer must call explicitly.

Slightly better UX would be to add an option, defaulted to 0, to the Redis constructor.

Discussed in #61

^{Originally posted by MichKonSher April 12, 2023}
Hello!
Is it possible to select db on Redis intance, such as db0, db1. e.t.c.?
I didn't find possibility to do this or to execute custom command.

[MichKonSher]

Slightly better UX would be to add an option, defaulted to 0, to the Redis constructor.

I think it shouldn't be the only one way to set DB number.
I have possible situations when one Redis object using to interact with different DB numbers.

[rpj]

I think it shouldn't be the only one way to set DB number.
I have possible situations when one Redis object using to interact with different DB numbers.

This is excellent feedback @MichKonSher, thank you!

Agreed: the constructor option, if implemented at all, should be syntactic sugar around the primary interface which will be the explicit implementation of the Redis::select() command. 👍

[holla2040]

Do you see a use case for selecting a DB at runtime (after the constructor is called)?

[MichKonSher]

@holla2040
Yes

1. For testing. Here i can get data from evaluating DB and write data to testing DB to do not affect evaluating DB
2. I'll use different DB-s for different environments (1 for critical home temperature regulation and 1 more for non critical info center service) and send some common data (such as temperature/humidity e.t.c) to both without needs to reconnect to Redis. Here i can split critical and non critical environments, grant external access to non critical DB, analyze it and only after it merge required data to critical segment.