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Difference between revisions of "EclipseLink/Development/DBWS/ParseDDLDS"
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= Parsing DDL for Metadata = | = Parsing DDL for Metadata = | ||
| − | The primary job of the <tt>DBWSBuilder</tt> utility is to extract metadata from the database about some artifact | + | The primary job of the <tt>DBWSBuilder</tt> utility is to extract metadata from the database about some artifact (i.e. a Table or a StoredProcedure) that is to be used as the basis of a (JAX-WS compliant) Web Service. The <tt>DBWSBuilder</tt> translates the information (fields, arguments, scalar or complex datatypes, etc.) into DBWS runtime artifacts (e.g. EclipseLink Project XML files, JAX-WS Provider class, etc.) Thus it is crucial that <tt>DBWSBuilder</tt> get complete and accurate metadata from the database. |
| − | For Oracle databases, <tt>DBWSBuilder</tt> uses a modified cut-down version of the JPublisher classes to send SQL queries to Data Dictionary views (<tt>ALL_OBJECTS</tt>, <tt>ALL_ARGUMENTS</tt>, etc.) that is then converted to an in-memory object-graph of all relevant information about the specific database artifact required for the Web Service. This object-graph is then ''walked'' | + | For Oracle databases, <tt>DBWSBuilder</tt> uses a modified cut-down version of the JPublisher classes to send SQL queries to Data Dictionary views (<tt>ALL_OBJECTS</tt>, <tt>ALL_ARGUMENTS</tt>, etc.) that is then converted to an in-memory object-graph of all relevant information about the specific database artifact required for the Web Service. This object-graph is then ''walked'' and the required DBWS runtime artifacts generated. |
| + | |||
| + | Unfortunately, the information in the Data Dictionary views can be (under certain circumstances) incomplete or inaccurate, or the in-memory object-graph constructed from the views can be distorted. | ||
Revision as of 16:12, 31 May 2011
Parsing DDL for Metadata
The primary job of the DBWSBuilder utility is to extract metadata from the database about some artifact (i.e. a Table or a StoredProcedure) that is to be used as the basis of a (JAX-WS compliant) Web Service. The DBWSBuilder translates the information (fields, arguments, scalar or complex datatypes, etc.) into DBWS runtime artifacts (e.g. EclipseLink Project XML files, JAX-WS Provider class, etc.) Thus it is crucial that DBWSBuilder get complete and accurate metadata from the database.
For Oracle databases, DBWSBuilder uses a modified cut-down version of the JPublisher classes to send SQL queries to Data Dictionary views (ALL_OBJECTS, ALL_ARGUMENTS, etc.) that is then converted to an in-memory object-graph of all relevant information about the specific database artifact required for the Web Service. This object-graph is then walked and the required DBWS runtime artifacts generated.
Unfortunately, the information in the Data Dictionary views can be (under certain circumstances) incomplete or inaccurate, or the in-memory object-graph constructed from the views can be distorted.