Building Queries and Data Views
The reality is that the development of global business and distributed systems has generated information in many other forms as well such as in packaged enterprise information system (EIS) applications (PeopleSoft, Siebel, etc.), and in emerging net-based technologies like Web services and XML documents.
All types of businesses and other organizations use a RDBMS (relational database management system) to store information. Relational refers to the way the database maintains information — in logical tables with rows and columns. Instead of a series of static records with one or more data fields that can be redundant from one file to another, information is directly accessible using queries.
Note: When Data View Builder inspects the metadata for a relational database, if the schema contains any columns that start with numeric values, the Data View Builder adds an underscore character (_) to the beginning of the element name that represents the column. For example, if you have a column in the database named
123_COLUMN, the element corresponding to that column in the Data View Builder is labeled
Additionally, if you are hand-editing queries, the element or attribute names that refer to column names that start with a numeric value must begin with an underscore character (_) when used in XPath expressions.
Extensible Markup Language (XML) files are proving to be a convenient and portable format for storing many different kinds of information for document processing and information exchange. Liquid Data and Data View Builder supports use of XML files as data sources.
A web service is a self-contained, platform-independent unit of business logic, located somewhere on the Internet, that is accessible through standards-based Internet protocols like HTTP or SMTP. Web services facilitate application-to-application communication over the Internet or within and across enterprises. A familiar example of an externalized web service is a weather portlet or stock quotes that you can integrate into your web browser. You can use web services to encapsulate information and operations. Web services are becoming important resources of global business information. Liquid Data and the Data View Builder support the use of web services as data sources.
Enterprise Information Systems (EIS) and custom applications store information that you might need to aggregate for a complete view of data. You can query and retrieve subsets of relevant information from applications such as SAP, Siebel, PeopleSoft, Oracle Financial and so on and treat the results as application view data sources in your data integration solution.
A Data View is a special type of data source in which the result of a query is used as a data source. The query result will change if your underlying data changes. In this way, you can build on the queries you design to create "views on data views" for an up-to-date picture of continually changing information. To learn more about Data Views see Using Data Views.
Spreadsheets provide a useful means of storing and manipulating information, especially information which needs to be changed quickly. You can use spreadsheet data that has been saved in comma separated value (CSV) file format in Liquid Data queries and data views. Although the separator field is conventionally referred to as a comma you can set the separator to be any ASCII character using the Liquid Data node of the WebLogic Administration Console. See "Configuring Access to Delimited Files" in the Liquid Data Administration Guide.