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Use ALTER VIEW to drop a constraint

SQL> SQL> -- create demo table SQL> create table Employee(   2    ID                 VARCHAR2(4 BYTE)         NOT NULL,   3    First_Name         VARCHAR2(10 BYTE),   4    Last_Name          VARCHAR2(10 BYTE),   5    Start_Date         DATE,   6    End_Date           DATE,   7    Salary             Number(8,2),   8    City               VARCHAR2(10 BYTE),   9    Description        VARCHAR2(15 BYTE)  10  )  11  / Table created. SQL> SQL> -- prepare data SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2               values ('01','Jason',    'Martin',  to_date('19960725','YYYYMMDD'), to_date('20060725','YYYYMMDD'), 1234.56, 'Toronto',  'Programmer')   3  / 1 row created. SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2                values('02','Alison',   'Mathews', to_date('19760321','YYYYMMDD'), to_date('19860221','YYYYMMDD'), 6661.78, 'Vancouver','Tester')   3  / 1 row created. SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2                values('03','James',    'Smith',   to_date('19781212','YYYYMMDD'), to_date('19900315','YYYYMMDD'), 6544.78, 'Vancouver','Tester')   3  / 1 row created. SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2                values('04','Celia',    'Rice',    to_date('19821024','YYYYMMDD'), to_date('19990421','YYYYMMDD'), 2344.78, 'Vancouver','Manager')   3  / 1 row created. SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary,  City,       Description)   2                values('05','Robert',   'Black',   to_date('19840115','YYYYMMDD'), to_date('19980808','YYYYMMDD'), 2334.78, 'Vancouver','Tester')   3  / 1 row created. SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)   2                values('06','Linda',    'Green',   to_date('19870730','YYYYMMDD'), to_date('19960104','YYYYMMDD'), 4322.78,'New York',  'Tester')   3  / 1 row created. SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)   2                values('07','David',    'Larry',   to_date('19901231','YYYYMMDD'), to_date('19980212','YYYYMMDD'), 7897.78,'New York',  'Manager')   3  / 1 row created. SQL> insert into Employee(ID,  First_Name, Last_Name, Start_Date,                     End_Date,                       Salary, City,        Description)   2                values('08','James',    'Cat',     to_date('19960917','YYYYMMDD'), to_date('20020415','YYYYMMDD'), 1232.78,'Vancouver', 'Tester')   3  / 1 row created. SQL> SQL> -- display data in the table SQL> select * from Employee   2  / ID   FIRST_NAME LAST_NAME  START_DAT END_DATE      SALARY CITY       DESCRIPTION ---- ---------- ---------- --------- --------- ---------- ---------- --------------- 01   Jason      Martin     25-JUL-96 25-JUL-06    1234.56 Toronto    Programmer 02   Alison     Mathews    21-MAR-76 21-FEB-86    6661.78 Vancouver  Tester 03   James      Smith      12-DEC-78 15-MAR-90    6544.78 Vancouver  Tester 04   Celia      Rice       24-OCT-82 21-APR-99    2344.78 Vancouver  Manager 05   Robert     Black      15-JAN-84 08-AUG-98    2334.78 Vancouver  Tester 06   Linda      Green      30-JUL-87 04-JAN-96    4322.78 New York   Tester 07   David      Larry      31-DEC-90 12-FEB-98    7897.78 New York   Manager 08   James      Cat        17-SEP-96 15-APR-02    1232.78 Vancouver  Tester 8 rows selected. SQL> SQL> CREATE VIEW myView AS   2  SELECT *   3  FROM employee   4  WITH READ ONLY CONSTRAINT my_view_read_only; View created. SQL> SQL> desc myView;  Name                    Null?    Type  ------------------------  ID                      NOT NULL VARCHAR2(4)  FIRST_NAME                       VARCHAR2(10)  LAST_NAME                        VARCHAR2(10)  START_DATE                       DATE  END_DATE                         DATE  SALARY                           NUMBER(8,2)  CITY                             VARCHAR2(10)  DESCRIPTION                      VARCHAR2(15) SQL> SQL> ALTER VIEW myview   2  DROP CONSTRAINT my_view_read_only; View altered. SQL> SQL> desc myView;  Name                             Null?    Type  ---------------------------------  ID                               NOT NULL VARCHAR2(4)  FIRST_NAME                                VARCHAR2(10)  LAST_NAME                                 VARCHAR2(10)  START_DATE                                DATE  END_DATE                                  DATE  SALARY                                    NUMBER(8,2)  CITY                                      VARCHAR2(10)  DESCRIPTION                               VARCHAR2(15) SQL> SQL> drop view myView; View dropped. SQL> -- clean the table SQL> drop table Employee   2  / Table dropped. SQL>