To see list of all existing users:
select * from DBA_USERS
To see list tables for a given user:
select table_name from ALL_TABLES WHERE OWNER='ARTEM49'
To create a new table:
CREATE TABLE signup
(
userid NUMBER(6),
day VARCHAR2(20),
in1 VARCHAR2(25),
out1 VARCHAR2(25)
)
Sample insert statement:
insert into signup values(1, 'd', 'Tuesday', 'Saturday')
To retrieve the version of Oracle:
select * from v$version where banner like 'Oracle%';
Update statement example:
update signup set out1='Thursday' where in1='Wednesday'