Example: Creating a database view in Oracle using the sdetable command
You can use the sdetable command to create a view in a geodatabase in Oracle. Doing so automatically registers the view with ArcSDE.
The example in this topic shows how a view created by sdetable can be used to restrict user access to specific data. The example is based on a table with the following definition:
CREATE TABLE employees ( emp_id number(38) unique not null, name varchar2(32), department number not null, hire_date date not null);
Notice that the table contains a not null number column that can be used as an ArcSDE row ID.
Create a view using the sdetable command
Suppose you want the manager of department 101 to see all the columns in the table employees but only the rows for employees in department 101. Use sdetable to create a view with all rows in which the department number is 101. The –w option specifies the WHERE clause of the query stored with the view definition.
sdetable –o create_view –T view_dept_101 –t employees –c 'emp_id,name,department,hire_date' -w "where department = 101" –u gdb –p gdb.bdg –i sde:oracle11g:ora1 -s myodbserver Attribute Administration Utility __________________________________ Successfully created view view_dept_101.
For more information on the sdetable command, see the Administration Command Reference.
You could subsequently query ALL_VIEWS to see a description of view_dept_101.
set lines 60 set pages 10000 set long 2000 column text format a60 wrapped; SELECT view_name, text_length, text FROM all_views WHERE owner = 'GDB' and view_name = 'VIEW_DEPT_101';
VIEW_NAME |
TEXT_LENGTH |
TEXT |
---|---|---|
VIEW_DEPT_101 |
112 |
SELECT "EMP_ID","NAME","DEPARTMENT","HIRE_DATE", FROM GDB.EMPLOYEES WHERE department = 101 |
In this example, ArcSDE has added the owner name to the table name in the query. If you create your own view with SQL, this is not done automatically.
Notice that the names of the view and its owner are converted to uppercase before being stored in ALL_VIEWS. This is done by Oracle, not ArcSDE. Therefore, when querying for these specific text values, you must type them in uppercase.
Some users create registered views with sdetable –o create_view and alter the view definition using SQL. This is done to avoid complex sdetable –o create_view command line syntax (especially the –c option) or to include a more complex or extended view definition, such as one that uses connections to external databases. Although altering a view can solve some problems, it is also possible to create a view that does not work well with ArcSDE or ArcSDE clients such as ArcGIS Desktop.
Grant privileges on the view
The view owner can grant privileges on the view to specific users without having to grant those users access to the base table (employees). In this example, the user mgr100 is granted select privileges on the view, view_dept_101:
SQL> GRANT SELECT ON view_dept_101 TO mgr100; Grant succeeded.
In this example, the table owner and the view owner are the same user. If they were different, the table owner would need to grant the view owner privileges to select from the table plus the ability to grant select to other users. If the privilege is granted using SQL, include the WITH GRANT OPTION in the statement. If the privilege is granted using the sdetable command with the grant operation, the inherit (–I) option must be specified.
Test privileges
Log in as mgr100 and select records from view_dept_101.
conn mgr100/mgr100 Connected. SQL> SELECT * FROM gdb.view_dept_101; EMP_ID NAME DEPT HIRE_DATE 29 YAN WU 101 04/15/2002 67 LEE VAN 101 11/01/2004 78 SUE CHO 101 05/31/2005 105 DAN HO 101 10/01/2006 111 ANN ANG 101 12/15/2006 135 BILL BO 101 10/15/2007
As expected, only records for employees in department 101 are returned.
Views exist as schema objects, independent of the tables that populate them. In the following query, the user mgr100 has no access to the table, employees, so it appears to mgr100 that the employees table does not exist.
SQL> SELECT * FROM gdb.employees; select * from gdb.employees * ERROR at line 1: ORA-00942: table or view does not exist