Example: Creating a database view in Informix using SQL and registering it with ArcSDE

Complexity: Beginner Data Requirement: Use your own data

You can use SQL to create a view in an ArcSDE geodatabase. To query the view with ArcGIS, you must register it with ArcSDE.

To register the view with ArcSDE, the underlying table from which the view is created must contain a qualifying row ID column. Row IDs are unique, nonnull integer columns used by ArcSDE to uniquely identify rows in a table or view. Although you can create a view without registering a row ID column, such a view has limited functionality in ArcGIS because a registered row ID column is required for selections and queries in ArcGIS.

The example in this topic shows how a view created in IBM Informix using SQL can be registered with ArcSDE. The example is based on a table with the following definition:

CREATE TABLE employees(
  emp_id integer not null, 
  name varchar(32), 
  department smallint not null, 
  hire_date datetime not null;

Notice that the table contains a not-null integer column that can be used as an ArcSDE row ID (emp_id). This column must be included in the view definition to allow you to register it with ArcSDE.

Grant privileges on the table

If the user creating the view is not the owner of the table or tables on which the view is based, the table owner must grant the view creator at least the privilege to select from the table. If the view owner needs to be able to grant privileges on the view to other users, the table owner must grant the view owner the ability to grant privileges to other users.

In this example, the table on which the view is based (employees) is owned by the user gdb. The user creating the view is user rocket. Additionally, the rocket user must grant privileges on the view to other users. Therefore, the gdb user must grant the rocket user the privilege to select from the employees table and include the WITH GRANT OPTION so rocket can grant other users select privilege on the view.

ON employees 

Create a view

In this example, user rocket creates a view on the employees table to restrict access to only those records where the department is 201.

CREATE VIEW view_dept_201 
AS SELECT emp_id, name, department, hire_date
FROM gdb.employess 
WHERE department = 201;

Grant privileges on the view

You 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 mgr200 is granted select privileges on the view, view_dept_201:

GRANT SELECT ON view_dept_201 TO mgr200;

Test privileges

Log in as mgr200 and select records from view_dept_201.

SELECT * FROM rocket.view_dept_201; 

emp_id   name       dept   hire_date 
112      LOLLI POP  201    06/30/2007 
134      VAN CHIN   201    10/15/2007 
150      DON GUN    201    03/01/2009

As expected, only records for employees in department 201 are returned.

Register the view with ArcSDE

To query or select records in a view from an ArcGIS client application, you must register the view with ArcSDE. Registering the view with ArcSDE adds a record to the ArcSDE TABLE_REGISTRY system table.

Use the sdetable command with the register operation to register the view. Only the owner of view can register it with ArcSDE. Therefore, the rocket user name and password must be provided with the sdetable command when registering view_dept_201.

sdetable -o register -t rocket.view_dept_201 -c emp_id -C SDE 
-i sde:informix -s myidsserver -D testdb -u rocket -p nopeeking

In this example, the row ID (emp_id) is registered as maintained by ArcSDE. If your view is read-only, you can register the row ID as user maintained.

For more information on the sdetable command, see the Administration Command Reference.