【正文】 s puter as a Client, run the database of Computer as Server. But this work intra, such as connecting all employees intra, of course, can also be inter. Shown in Figure 4, in the threetier model, the order will be sent to Service the middle layer, and middle layer will be sent to the database SQL statements. Database handle SQL statement and the results back, middle layer, then middle layer of their customers back. MIS administrators will find the threetier model very attractive because the middle Layer of the visit can control and coordination of the update database, another advantage is that if there is a middle layer users can use an easytouse highlevel The API, this API can be by the middle layer for conversion into the bottom of the call. Moreover, in many cases, the threetier model can provide better performance. So far, the middle layer is usually used C or C + + implementation, in order to guarantee its performance. However, with the introduction of piler optimization to java byte code conversion Into efficient machine code, using java to achieve middle layer will be more practical. And JDBC are a permit from the java middle layer the key to access the database. 。s beautiful packaging. 4. JDBC twotier model and the threetier model 山西大學本科畢業(yè)論文（設(shè)計）外文翻譯資料 JDBC support for a twotier model, also supported the threetier model for database access. Shown in Figure 3, a twotier model, a java Appple or a JAva application directly with the database connection. This need to be able to directly access the database Connect to the JDBC driver. The user39。 and depositors Check required by the SQL call to be a direct consequence of inhouse. Can also achieve more plex mapping, such as tables of many firms of a Java implementation of the class. With the . on the continuing strong interest in JDBC, a growing number of developers 山西大學本科畢業(yè)論文（設(shè)計）外文翻譯資料 have begun to use JDBCbased tools for development. This development work has bee Easy. At the same time, programmers are also being developed for endusers easier access to the database applications. 3. JDBC and ODBC, and other API Comparison So far, Microsoft39。 2) Send SQL statements to the database。s SQLServer. Writing with JDBC procedures can automatically SQL Statement sent to the appropriate database management system (DBMS). Not only that, the use of Java applications can be prepared at any support running on Java platform, not Must in the preparation of different platforms on different applications. The bination of Java and JDBC allows developers to develop database applications really achieve WriteOnce, RunEverywhere! Java has a robust, secure, easytouse and other characteristics, but also support the automatic downloading, in essence, is a good database application programming language. It needs Java application is how to work with various database connection, JDBC is the key to achieve this connection. JDBC expanded the ability of Java, such as the use of Java and JDBCAPI can 山西大學本科畢業(yè)論文（設(shè)計）外文翻譯資料 publish a Web page, page with access to remote databases Ap plet. Either Enterprises through JDBC to allow all the workers (who can use different operating systems, such as Windwos, Machintosh and UNIX) at In tra up to connect to the On a number of global databases, which can be several global databases are not identical. As more and more developers use Java language, Java access to data Treasury ease the demand for more and more strongly. MIS managers like Java and JDBC, as it can more easily publish information economically. Variety has been installed in the database of affairs will continue to deal with Normal operation, and even deal with