information_schema.processlist.db

mysql

type: VARCHAR NULL
5.7-8

mariadb

type: NULL
Note:
Default database, or NULL if none.
© 2022 MariaDB
5.1-10.8

tidb

type: VARCHAR(64) NULL
Note:
The name of the currently connected default database.
© 2022 PingCAP
4-6.1

postgres

cockroachdb

mssql