show databases;

mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| istester |
| mysql |
| performance_schema |
| sys |
+--------------------+

mysql> use istester;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed

mysql> select database();
+------------+
| database() |
+------------+
| istester   |
+------------+
1 row in set (0.00 sec)

mysql> show tables;
+--------------------+
| Tables_in_istester |
+--------------------+
| idoxu              |
| istester           |
| istester2          |
+--------------------+
3 rows in set (0.03 sec)