Oracle PL/SQL Tutorial/System Tables Data Dictionary/user views

30. Getting a list of your own views

SQL>
SQL>
SQL> SELECT view_name FROM user_views where rownum < 50;
VIEW_NAME
------------------------------
APPLICATION_USERS
AUTHOR_PUBLICATION
AVG_EVALUATIONS
COURSE_DAYS
CRS_OFFERINGS
DEPT20_V
DEPT_OR
EMP_V
EMP_VIEW
HRC_ORG_SITE
SALES_BY_ATLAS_V
SALES_PER_PERSON_V
USER_AVAIL_TRACE_FILES
13 rows selected.
SQL>
SQL>

30. You can get information about your views from user_views

SQL>
SQL> desc user_views;
 Name                    Null?    Type
 ------------------------
 VIEW_NAME               NOT NULL VARCHAR2(30)
 TEXT_LENGTH                      NUMBER
 TEXT                             LONG
 TYPE_TEXT_LENGTH                 NUMBER
 TYPE_TEXT                        VARCHAR2(4000)
 OID_TEXT_LENGTH                  NUMBER
 OID_TEXT                         VARCHAR2(4000)
 VIEW_TYPE_OWNER                  VARCHAR2(30)
 VIEW_TYPE                        VARCHAR2(30)
 SUPERVIEW_NAME                   VARCHAR2(30)
SQL>
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>
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>
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> SELECT view_name, text_length, text
  2  FROM user_views  where view_name="MYVIEW";
VIEW_NAME                      TEXT_LENGTH TEXT           MYVIEW                                 
120 SELECT "ID","FIRST_NAME","LAST_NAME","START_DATE","END_DATE","SALARY","CITY","DE
SQL>
SQL> drop view myView;
View dropped.
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /
Table dropped.
SQL>
SQL>