Software Tutorial: Parsing the JBuilder Database Application

Programs are programs that access stored data and allow you to view, modify, or manipulate the data. In most cases, the data is stored in a database. However, the data can also be stored as text or in other formats. JBuilder allows you to access this data and manipulate it in the DataExpress component library along with the properties, methods, and events defined in the JavaBean Component Library (JBCL) DataSet and dbSwing packages.

A database application that requests information from a data source (such as a database) is called a client application. A DBMS (Database Management System) that processes data requests from various clients is called a database server.

JBuilder's DataExpress architecture is primarily about building pure Java client/server applications and applets for the Internet or intranet. Because the applications you create in JBuilder are pure Java, they are cross-platform.

The JBuilder application communicates with the database server via the JDBC API. The JDBC API is a specification for JavaSoft database connections. JDBC is a pure Java industry standard API for accessing and manipulating database data. The JBuilder database application can connect to any database with a JDBC driver.

Main components of a database application

DataSet

A DataSet is an abstract class. A large number of public APIs for all DataSets appear in this class; all DataSet navigation, data access, and updated APIs appear in this class; support for master-slave relationships, row sorting, and row filtering appears in this class. All data recognition JBCL and dbSwing controls have a DataSet property. This means that Grid Control or JdbTable can have its DataSet property set to various extensions of the DataSet: DataSet View, Query DataSet, Procedure DataSet, and Table DataSet.

StorageDataSet

StorageDataSet can use the memory in memory (MemoryStore) to buffer its data. The StorageDataSet Store property can also be set to a DataStore component to provide persistent persistence for DataSet data. The StorageDataSet manages the storage of DataSet data to maintain the index of the data change view and the persistent Column state. All structured APIs (add/delete/change/move columns) appear in this class. Because it manages data, it also automatically logs updates, inserts, and deletes for all rows. Because all changes to the StorageDataSet are tracked, we know exactly what needs to be done to restore the various changes that occurred during the operation to the data source.

DataStore

The DataStore component provides high-performance data caching and compression persistence for DataExpress DataSets, arbitrary files, and Java objects. The DataStore component uses a single file to hold one or more data streams. The DataStore file has a hierarchical directory structure. It associates a name and directory state with a particular data stream.

DataSetView

This component can be used to provide independent navigation (cursors). Its row sorting and filtering is different from the way the basic DataSet is used. To use this component, you need to set the Storage DataSet property of the DataSetView component. When multiple controls need to be dynamically converted to a new DataSet, this component control can be connected to the same DataSetView. To force them to both view the new DataSet, you can change the properties of the DataSetView Storage DataSet.

QueryDataSet

This is a JDBC-specified DataSet. It manages a JDBC data provider. The data to be provided is specified in the properties of the Query. The Query property specifies a SQL statement.

ProcedureDataSet

This is a JDBC-specified DataSet. It manages a JDBC data provider. The data to be provided is provided with the Procedure property. The Procedure property specifies a stored procedure.

TableDataSet

This is a generic DataSet component without a built-in provider mechanism. Although it does not have a default provider, it can still be used to parse its changes back to the data source. TableDataSet, Column, and data can be added through the DataSet method, or by importing data with a Data File component like Text Data File.

JBuilder's DataExpress Architecture

The DataExpress component is designed as a module that allows separation of key functions. This design allows the DataExpress component to handle a wider variety of applications. The modular features of the DataExpress architecture include:

Core DataSet (



This is a collection of data processing functions available to DataExpress applications. This feature can be applied using declarative properties and setting events. This feature includes navigation, data access/updates, sorting/filtering of data, master-slave support, lookups, constraints, defaults, and more.

Data source independence

Separating data from a data source such as Oracle or Sybase services is separated into two key interfaces: the provider/parser (resolver) ). By seamlessly separating data acquisition and updates into two interfaces, it is easy to create new provider/parser components for new data sources. There are two vendor/parser implementations for standard JDBC drivers that provide access to popular databases. For example, support for Oracle, Sybase, Informix, InterBase, DB2, MS SQL Server, Paradox, dBASE, FoxPro, Access, and other popular databases. In the future, borland.com and third parties can create execution code for client provider/parser components for EJBs, application servers, SAP, BAAN, IMS, CICS, and more.

Pluggable storage

When data is obtained from a provider, it is buffered in the DataSet. All edits made to the buffered DataSet are tracked so that the parser code section knows what needs to be updated into the data source. DataExpress provides two options for this buffer: MemoryStore (default) and Data Store. MemoryStore buffers all data and data edits into memory. DataStore uses a pure Java, small scale, high performance, embeddable database to buffer data and data editing. DataStore is ideal for disconnected/mobile computing, asynchronous data replication, and small-scale database applications.

Data binding support for visual component

The DataExpress DataSet component provides a powerful programming interface and direct data binding for data identification components. stand by. Such as grids, lists, and fields in the Visual Designer, navigate through points and click on property settings. JBuilder is provided with the Java JFC based on visual components, which are directly bound to the DataSet component.

Advantages of the Modular DataExpress Architecture

Network Computing

As mentioned earlier, the provider/parser method isolates the interaction with any data source in two In an irrelevant module. There are two other benefits to this approach:

1. The provider/parser can be easily divided into an intermediate layer. Because the provider/parser logic generally has the nature of a transaction, it is ideal to partition into an intermediate layer.

2. This is a stateless computing model. Ideal for network computing, the connection between the DataSet component client and the data source can be broken after use. When you need to restore changes back to the data source, you only need to reestablish the connection during the transaction.

Rapid Development of User Interfaces

Because DataSets can be bound to a data recognition component with simple properties, they are ideal for quickly building database application user interfaces.

Mobile Computing

With the introduction of the DataStore component, the DataExpress application has a persistent and portable database. The DataStore can contain multiple DataSets, arbitrary files, and Java objects. This allows an application state to remain intact in a single file storage space. The DataSet has built-in data replication technology that can be used to save and adjust edits to replicated data to a single data source.

Embedded Applications

A small-scale, high-performance DataStore database is ideal for embedded applications and supports the full functionality and semantics of the DataSet component.