Oracle oem statements

OEM:
Http: // full computer name: 5500/em/

Sys/
System manager
Scott tiger
1. Forget the logon password of a user except SYS and SYSTEM.
Log On As a sys (or SYSTEM) user.
Conn sys/PASS_WORD as sysdba;
Use the following statement to modify the user password.
Alter user user_name identified by newpass;
Table integrity:
1. entity integrity-UK ensures the uniqueness of data from the database perspective (unique constraint)
2. Domain integrity-PK
3. Integrity-FK
Constraints:
Primary key constraint: PK

Foreign key constraint: FK

CHECK constraints: (within a certain range)
For example
Alter table emp add constraint ch_emp_sex CHECK (sex = 'male' or sex = 'female ');
SQL> desc dba_constraint;
SQL> desc all_constraint;
SQL> desc user_constraint;
Dba_views/all_views/user_views

Non-empty constraint:
NOT NULL


Author: hunter090730