Matakuliah Tahun Versi : M0174/OBJECT ORIENTED DATABASE : 2005 : 1/0 Pertemuan 19 Building Object Database Application (Lanjutan bagian 2) 1 Learning Outcomes Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu : • Mahasiswa dapat Menjelaskan ikatan antara programming language dengan object database (C2) • Mahasiswa dapat Menjelaskan pembuatan object database application (C2) 2 Outline Materi • • • • • Creating object and deleting object Modification object Manipulating relationship Manipulating named object OQL queries 3 Creating and Deleting Object • C++ OML provides features for accessing and manipulating the contents of an object database. This is done mostly in such a way that the C++ ODL create, deletes, and manipulates persistent objects in the same way that C++ does for “conventional” transient objects. 4 Modification object • The state of an object (transient or persistent) is changed by either updating its properties or executing operation on it • Example 5 Manipulating relationship • Relationships are implemented in C++ OML/ODL as data member defined on Ref classes. • The value of a relationship data member can therefore comprise one or more references to persistent (or transient) object 6 Manipulating named object • The C++ ODL/OML allows us to name individual objects and use the object names to retrieve the named object • The object names provide access points into an object database 7 OQL queries • OQL queries can be executed from within C++ OML/ODL programs in two ways either by using the queries operation on collection objects or by using the OQL_Query interface 8 OQL queries • Examples D_OQL_Queries q(“select so.place_by from salesorders so where so.date > $1”); q << earliest_order_date; D_oql_execute (q, result); 9 SUMMARY • C++ OML uses the additional built-in classes to create, delete, and manipulate persistent objects • In Addition, OQL queries can be executed via a loose binding, using query or oql operations 10
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