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| | | Mike Norman | | | Mike Norman |
| | | 1.0 | | | 1.0 |
| | + | |- |
| | + | | 081130 |
| | + | | Mike Norman |
| | + | | 2.0 - use JPub to get metadata |
| | |} | | |} |
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| | == DBWS utility enhancement: Improved DataDictionary Queries == | | == DBWS utility enhancement: Improved DataDictionary Queries == |
| − | | + | With the decision to use a stripped-down version of JPub to get database metadata, [https://bugs.eclipse.org/bugs/show_bug.cgi?id=234681 bug 234681 ] |
| − | === Motivation ===
| + | changes from <br /> 'Improve DBWSBuilder utility's use of database metadata to support more auto-generated cases' to <br /> |
| − | | + | 'DBWSBuilder utility auto-generate XR artifacts for complex PL/SQL arguments' |
| − | [https://bugs.eclipse.org/bugs/show_bug.cgi?id=234681 bug 234681 ] <br/> | + | |
| − | The key for the DBWSBuilder to support multiple database platforms (Oracle, DB2, Sybase, MS SQLServer, etc.) lies in the ability to extract meta-data for Stored Procedures and Tables from the database. The standard JDBC meta-data APIs (available through the <b><code>java.sql.DatabaseMetaData</code></b> interface) unfortunately is not fully implemented across vendors, nor in a standard fashion.
| + | |
| − | For example, the simple act of getting the <b><i>names</i></b> of available databases is different across platforms: on Oracle the <b><code>getSchemas()</code></b> method is used while for DB2/Sybase/MS SQLServer the <b><code>getCatalogs()</code></b> method is used. Another example of cross-platform meta-data issues is the <b><code>getColumns</code></b> method: for PostgreSQL, the name of the table <u>must</u> be lower-case; for Oracle, it <u>must</u> be upper-case; others support mixed-case. A case-study found [http://www.sun.com/bigadmin/content/submitted/jdbc_drivers.html here] expands on these issues and a list of outstanding JDBC driver issues can be found [[EclipseLink/Development/DBWS/ImprovedDataDictionaryQueries/OutstandingJDBCDriverIssues|here]].
| + | |
| − | | + | |
| − | == Database Metadata Model Objects Refactoring ==
| + | |
| − | Database metadata is represented by Java model objects. In EclipseLink, these model classes are spread across several packages and components:
| + | |
| − | # <tt>o.e.p.internal.helper</tt> - <tt>DatabaseType</tt>, <tt>DatabaseTable</tt>, <tt>DatabaseField</tt>
| + | |
| − | # <tt>o.e.p.tools.schemaframework</tt> - <tt>TableDefinition</tt>, <tt>FieldDefinition</tt>, <tt>TypeDefinition</tt>
| + | |
| − | # <tt>o.e.p.platform.database.oracle.plsql</tt> - <tt>PLSQLrecord</tt>, <tt>PLSQLargument</tt>, <tt>OraclePLSQLTypes</tt>
| + | |
| − | # (in Utils component) <tt>o.e.p.tools.dbws.jdbc</tt> - <tt>DbTable</tt>, <tt>DbColumn</tt>, <tt>DbStoredProcedure</tt>
| + | |
| − | | + | |
| − | In addition to the above classes not being sufficient for DBWSBuilder's needs, there are some issues:
| + | |
| − | * code duplication: for example, 3 different classes describe Database tables
| + | |
| − | * limited or no code reuse: no common class/interface to extend/implement
| + | |
| − | * OSGi packaging restriction: any revision of the class hierarchy structure must obey the rules w.r.t. split packages
| + | |
| − | * violation of DRY (Don't Repeat Yourself) Principle: existing Eclipse DTP ModelBase sub-project solves the identical problem
| + | |
| − | | + | |
| − | === Options ===
| + | |
| − | # create a new optional bundle (similar to the existing EclipseLink bundles for ASM and ANTLR) containing all Database Metadata Model classes refactored to provide capabilities for both runtime and utilities. This would mean, for example, that EclipseLink runtime users that do not require DDL creation would not require the additional bundle; similarly, EclipseLink runtime users that do not use <tt>o.e.p.platform.database.oracle.plsql.PLSQLrecord</tt> would not require the new bundle. For users of the <tt>DBWSBuilder</tt> utility, the new bundle would not be 'mandatory' in an OSGi point-of-view, but the bundle - which is a <tt>.jar</tt>-file - would be required on the classpath in addition to the <tt>eclipselink.jar</tt> and the other required <tt>.jar</tt>-files pertaining to Web services development (javax.wsdl, javax.activation, javax.xml.soap jars)
| + | |
| − | # refactor
| + | |
With the decision to use a stripped-down version of JPub to get database metadata, bug 234681
changes from
'Improve DBWSBuilder utility's use of database metadata to support more auto-generated cases' to
'DBWSBuilder utility auto-generate XR artifacts for complex PL/SQL arguments'
