tailieunhanh - o'reilly database programming with JDBC and Java 2nd edition phần 2

những người hiện tại có thể cung cấp phát triển nhanh chóng của các giải pháp cho các công cụ cơ sở dữ liệu hỗ trợ các giao thức cũ. Cụ thể, Sun đã làm việc song song với Intersolv để tạo ra một cầu nối ODBC mà các bản đồ JDBC cuộc gọi đến các cuộc gọi ODBC, do đó đem lại cho các ứng dụng Java truy cập | JDBC and Java 2nd edition existing ones can provide quick development of solutions for database engines that support the old protocols. Specifically Sun worked in parallel with Intersolv to create an ODBC bridge that maps JDBC calls to ODBC calls thus giving Java applications access to any database management system DBMS that supports ODBC. The JDBC-ODBC bridge is a great tool for developers who are interested in learning JDBC but may not want to invest in anything beyond the Microsoft Access database that comes with Microsoft Office. When developing for production sites however you almost certainly want to move to a JDBC driver that is native to your deployment database engine. JDBC attempts to remain as simple as possible while providing developers with maximum flexibility. A key criterion employed by Sun is simply asking whether database access applications read well. The simple and common tasks use simple interfaces while more uncommon or bizarre tasks are enabled through specialized interfaces. For example three interfaces handle a vast majority of database access. JDBC nevertheless provides several other interfaces for handling more complex and unusual tasks. The Structure of JDBC JDBC accomplishes its goals through a set of Java interfaces each implemented differently by individual vendors. The set of classes that implement the JDBC interfaces for a particular database engine is called a JDBC driver. In building a database application you do not have to think about the implementation of these underlying classes at all the whole point of JDBC is to hide the specifics of each database and let you worry about just your application. Figure illustrates the JDBC architecture. Figure . The JDBC architecture If you think about a database query for any database engine it requires you to connect to the database issue your SELECT statement and process the result set. In Example you have the full code listing for a simple SELECT application from the .