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How do I insert, select, and update data in the relational tables using an object view?<p><B>Technique</B><p>The SELECT statement syntax used to extract data from an object view is not particularly noteworthy. INSERT and UPDATE statements are fairly straight-forward as well, unless the end result of the insert or update operation is to modify data residing in more than one base table. Oracle8 will not allow these operations by default; INSTEAD OF triggers provide a way for developers to overcome these limitations.<p>The name of this trigger type is indicative of its function. When an update state-ment fires an update INSTEAD OF trigger, for example, the trigger is executed instead of the originally issued update statement. INSTEAD OF triggers operate similarly for delete and insert operations. This type of trigger serves to resolve the ambiguity common to update operations on join views.<p><B>Steps</B><p><B>1.</B>	If you have not executed the scripts in the previous How-To, do so now by starting SQL*Plus, connecting as the WAITE user, and using the START command to load and execute the scripts CHP16_17.SQL, CHP16_18.SQL, CHP16_19.SQL, and CHP16_20.SQL. These scripts create two relational tables, two object types, and an object view. They are explained fully in the previous How-To.<p><B>2.</B>	Object views precipitate some changes to standard data manipulation language (DML). To see how, use the START command to load and execute the CHP16_21.SQL script. This script and its results appear in Listing 16.4.<p>Listing 16.4  A sample of DML statements issued against an object view<p><code><b>SQL> start chp16_21<p>SQL><p>SQL> SELECT *                                      -- 1<p>2  FROM empdept16;<p>EMPNO ENAME      JOB       MGR        HIREDATE     SAL     COMM<p>---------- ---------- --------- ---------- ------------ ------- -----------<p>DEPT(DEPTNO, DNAME, LOC)<p>---------------------------------------------------------------------------<p>1 FRANK      CEO                  25-OCT-97    72500   6<p>DEPT_TYPE16(1, 慖S
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