SQL/MX 2.x Installation and Management Guide (G06.24+, H06.03+)

Adding, Altering, and Dropping SQL/MX Database
Objects
HP NonStop SQL/MX Installation and Management Guide—523723-004
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Dropping Views
4. Enter the DROP TRIGGER statement.
5. Revise the application source code as needed to reflect your changes to the
database. Process and compile the updated source file. For more information, see
the SQL/MX Programming Manual for C and COBOL and the SQL/MX
Programming Manual for Java.
For more information and examples of dropping triggers, see the SQL/MX Reference
Manual.
Dropping Views
To drop a view of SQL/MX data, use the DROP VIEW statement. To drop a view, you
must own its schema or be the super ID.
The RESTRICT option, by default, will not allow a view to be dropped if it is referenced
in the query expression of any other view or in the search condition of another object's
constraint. The CASCADE option, if specified, will drop both the view and any such
dependent objects
Dropping a view with dependencies is essentially the same as dropping the view and
each of its dependent objects separately. Although SQL can drop all dependent
objects automatically, it does not drop any dependent programs. Dropping a view
invalidates all programs that use the view, however, and HP recommends that you
update and recompile these programs explicitly after dropping the view to avoid errors
and expensive, automatic recompilations.
For more information, see the SQL/MX Reference Manual.
Steps for Dropping a View
1. Start an MXCI session. Enter a LOG command to initiate a log file for statements
and commands entered in this session. Keep the log for your records.
2. Determine the name of the view you wish to drop.
3. Use the DISPLAY USE OF command to identify which user modules are
associated with this object. See the similarity check criteria in the SQL/MX
Programming Manual for C and COBOL and the SQL/MX Programming Manual for
Java to determine if your changes are likely to cause similarly check to fail and
force automatic recompilation. If they will, you should SQL compile these modules
after making the changes to avoid expensive automatic recompilations at run time.
SQL applications that are running while you make these changes will still undergo
automatic recompilation.
For information about explicit and automatic recompilation, see the SQL/MX
Programming Manual for C and COBOL and the SQL/MX Programming Manual for
Java. For information about using DISPLAY USE OF, see Checking Module
Dependencies With DISPLAY USE OF on page 11-20 and the SQL/MX Reference
Manual.