create database is not behaving normally

[cloudcarver]

Describe the bug

1. Drop database is not working.
2. A table in a database should be invisible to the other database.

To Reproduce

psql -h localhost -p 4566

1. create a database

mike=> create database test;

2. switch to the new database

mike=> \c test
test=>

3. drop database (bug 1: this database is dropped. but we can still use this database)

test=> drop database test;
DROP_DATABASE
test=> drop database test;
ERROR: Catalog error: database not found: test

4. create a datababse

test=> \c mike
psql (14.2, server 0.0.0)
You are now connected to database "mike" as user "mike".
mike=> create table t ();

5. switch to the database already dropped. (bug 1: we've already dropped this database before, but we can still switch to it)

mike=>\c test
psql (14.2, server 0.0.0)
You are now connected to database "test" as user "mike".
test=> 

5. show tables. (bug 2: table t is created in database mike, but it is visible in database test)

test=> show tables;
 Name 
------
 t
(1 row)

Expected behavior

1. Tables should be invisible to the other database
2. Dropped database should be dropped.

Additional context
Add any other context about the problem here.

[likzn]

Is below code the reason of it? Because we all use mock connection now so the operations are all in the same database.
https://github.com/singularity-data/risingwave/blob/fb519e5d47c4a6481cd91f49454dd403847104dd/src/utils/pgwire/src/pg_protocol.rs#L114-L126

[cloudcarver]

Is below code the reason of it? Because we all use mock connection now so the operations are all in the same database.

https://github.com/singularity-data/risingwave/blob/fb519e5d47c4a6481cd91f49454dd403847104dd/src/utils/pgwire/src/pg_protocol.rs#L114-L126

oh, make sense. This explains everything :)