Overview and Key Concepts

This section introduces key concepts you need to understand to plan, design, build and test queries using BEA Liquid Data for WebLogic^TM. The notion of a stored query versus an ad hoc query is introduced. Also covered is using a hand-coded query versus a Builder-generated query. Since we want to encourage most users to leverage the Data View Builder to generate queries for Liquid Data, many of the considerations and concepts introduced here assume use of the Builder, including a GUI overview for the Builder. However, key concepts that are relevant to all types of query-smiths are introduced here as well such as data sources, stored queries, data views, XQuery, the anatomy of a query (joins, unions, aggregates and so on), and the process of building and testing a query.

The following topics are covered.

• W3C XQuery, XML, and Liquid Data

• XQuery Use in Liquid Data and Data View Builder
• The Role of XML in Creating Global Business Solutions
• Supported XML Schema Versions In Liquid Data
• Learning More About the XQuery Language

• Data View Builder Overview

• Advantages of the Data View Builder
• How the Data View Builder Works

• Key Concepts of Query Building

• Query Plans
• Stored Queries
• Ad Hoc Queries
• Different Kinds of Data Sources
• Source and Target Schemas
• Anatomy of a Query: Joins, Unions, Aggregates, and Functions

• Understanding XML Namespaces
• Next Steps