The database application is a program that accesses stored data and allows you to view, modify, or operate them. In most cases, the data is stored in a database. However, data can also be stored as text or in other formats. JBuilder allows you to access these data and operate this data in the DataExpress component library with the DataSet package defined in the DataSet package in the Javabean component library (JBCL).
Database applications requested from a data source (such as database) are called a client application. DBMS (Database Management System, Database Management System) of data requests from various clients, called database servers. JBuilder's DataExpress architecture is primarily to build pure Java client / server applications and applets for Internet or intranet. Because the app created in JBuilder is pure Java, they are cross-platform. The JBuilder application communicates with the database server via JDBC API. JDBC API is a specification description of the JavaSoft database connection. JDBC is an API for accessing a pure Java industry standard for operating database data. The JBuilder database application can connect with any database with a JDBC driver. The main component of the database application DataSet DataSet is an abstract class. All DataSet's large number of public APIs appear in this class; all DataSet navigation, data access, and updated APIs appear in this class; support for main - from relationships, row lines, and row filtering appears in this class. All data identification JBCL and DBSWING controls have a DataSet property. This means that Grid Control or JDBTable allows its DataSet property to be set to DataSet: DataSet View, Query DataSet, Procedure Dataset, and Table DataSet. StorageDataSet StorageDataSet can buffer its data using the memoryStore in memory. The StorageDataSet Store property can also be set to a DataStore component to provide persistent saves for DataSet data. StorageDataSet manages the storage of DataSet data to maintain the index of the data change view, and the persistent Column state. All structural APIs (Add / Delete / Change / Movies) appear in this class. Because management data, it can also automatically record all rows of updates, insert, and delete. Because all changes of the StorageDataSet are tracked, we accurately know what you need to do, to return a variety of changes that happen during operation to the data source. DataStore DataStore components provide a high-performance data cache for persistent storage for DataExpress DataSet, any file, and Java. The DataStore component saves one or more data streams using a single file. The DataStore file has a hierarchical directory structure. It connects a name and directory status to a particular data stream. DataSetView This component can be used to provide separate navigation (cursors). Its row sorting and filtration are different from the methods used by the basic DataSet. To use this component, you need to set the Storage DataSet property of the DataSetView component. When multiple control needs to be dynamically converted to new DataSet, you can use this component control to connect to the same DataSetView. To force them to view new DataSets, 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 Query's properties. 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 general DataSet component without a built-in supplier mechanism. Although it has no default supplier, but can still be used to resolve it to the data source.
TableDataSet, Column, and data can be added to the data implementation of data by a DataSet method or by using a Data file component like a Text Data File. JBuilder's DataExpress architecture DataExpress component is designed as a module, allowing you to separate key features. This design allows DataExpress components to process more applications. The modular feature of the DataExpress architecture includes: Core DataSet (core DataSet) Function This is a collection of data processing functions for DataExpress applications. This feature can be applied using the declaration attribute and setting event. This feature includes navigation, data access / update, sorting / filtering, main - support, lookup, constraint, default, and more. Data Source Independence (Data Source Independence) From a data source, such as Oracle or Sybase service acquisition with update data is separated into two critical interfaces: Supplier / Resolver. By separating the data from the update cleanly to the two interfaces, it is easy to create a new source of supplier / parser components for new data sources. For standard JDBC drivers, there are two supplier / parsers, which provide access to popular databases. For example, support 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 the execution code of the client provider / parser component for EJBs, application servers, SAP, BAAN, IMS, CICS, etc.. Pluggable Storage (Insert Memory) When data is obtained from a supplier, it buffers in the DataSet. All edits made to buffered DataSet are tracked so that the parser code segment knows what needs to be updated to the data source. DataExpress provides two options for this buffer: MemoryStore and Data Store. MemoryStore buffers all data and data editing into memory. DataStore uses a pure Java, a small size, high-performance, and embedded database to buffer data and data editing. DataStore is ideal for detachment / movement computing, asynchronous data replication, and small-scale database applications. Data Binding Support for Visual Component (Data Binding Support) DataExpress DataSet component provides a powerful programming interface, as well as support for direct data binding of data identification components. For the grids, lists, and fields in the visual designer, through the navigation and click Property settings. JBuilder is provided with Java JFC based on visual components that bind directly to the DataSet component. Advantages of Modular DataExpress Architecture Advantage Network Calculation As previously mentioned, the supplier / parser method isolates the interaction with any data source in two inseparable modules. There are also two other benefits in this approach: 1. The supplier / parser can easily divide one intermediate layer. Since the supplier / parser logic is generally characterized by transactions, it is ideal for one intermediate layer. 2. This is a computational model of "stateless", which is ideal for network computing, and the connection between the DataSet component client and the data source can be disconnected later. When you need to return the change to the data source, you only need to reconstruct the connection during your transaction. The User Interface Quick Development Because the DataSet is set to a data identification component by simple attributes, they are ideal for fast building a database application user interface. Moving calculations With the introduction of the DataStore component, the DataExpress application has a persistent portable database.
