JDBC接口技術(shù)外文翻譯@中英文翻譯@外文文獻(xiàn)翻譯

山西大學(xué)本科畢業(yè)論文（設(shè)計）外文翻譯資料 外文出處 ： Exploiting Software How to Break Code By Greg Hoglund, Gary McGraw Publisher : Addison Wesley Pub Date : February 17, 2004 ISBN : 0-201-78695-8 譯文標(biāo)題： JDBC 接口技術(shù) 譯文： JDBC 是一種可用于執(zhí)行 SQL 語句的 JavaAPI（ ApplicationProgrammingInterface 應(yīng)用程序設(shè)計接口）。它由一些 Java 語言編寫的類和界面組成。 JDBC 為數(shù)據(jù)庫應(yīng)用開發(fā)人員、數(shù)據(jù)庫前臺工具開發(fā)人員提供了一種標(biāo)準(zhǔn)的應(yīng)用程序設(shè)計接口，使開發(fā)人員可以用純 Java 語言編寫完整的數(shù)據(jù)庫應(yīng)用程序。 一、 ODBC 到 JDBC 的發(fā)展歷程 說到 JDBC，很容易讓人聯(lián)想到另一個十分熟悉的字眼“ ODBC”。它們之間有沒有聯(lián)系呢？如果有，那么它們之間又是怎樣的關(guān)系呢？ ODBC 是 OpenDatabaseConnectivity 的英文簡寫。它是一種用來在相關(guān)或不相關(guān)的數(shù)據(jù)庫管理系統(tǒng)（ DBMS）中存取數(shù)據(jù)的，用 C 語言實現(xiàn)的，標(biāo)準(zhǔn)應(yīng)用程序數(shù)據(jù)接口。通 過ODBCAPI，應(yīng)用程序可以存取保存在多種不同數(shù)據(jù)庫管理系統(tǒng)（ DBMS）中的數(shù)據(jù)，而不論每個 DBMS 使用了何種數(shù)據(jù)存儲格式和編程接口。 1 ODBC 的結(jié)構(gòu)模型 ODBC 的結(jié)構(gòu)包括四個主要部分：應(yīng)用程序接口、驅(qū)動器管理器、數(shù)據(jù)庫驅(qū)動器和數(shù)據(jù)源。 應(yīng)用程序接口：屏蔽不同的 ODBC 數(shù)據(jù)庫驅(qū)動器之間函數(shù)調(diào)用的差別，為用戶提供統(tǒng)一的SQL 編程接口。 驅(qū)動器管理器：為應(yīng)用程序裝載數(shù)據(jù)庫驅(qū)動器。 數(shù)據(jù)庫驅(qū)動器：實現(xiàn) ODBC 的函數(shù)調(diào)用，提供對特定數(shù)據(jù)源的 SQL 請求。如果需要，數(shù)據(jù)庫驅(qū)動器將修改應(yīng)用程序的請求，使 得請求符合相關(guān)的 DBMS 所支持的文法。 數(shù)據(jù)源：由用戶想要存取的數(shù)據(jù)以及與它相關(guān)的操作系統(tǒng)、 DBMS 和用于訪問 DBMS 的網(wǎng)絡(luò)平臺組成。 雖然 ODBC 驅(qū)動器管理器的主要目的是加載數(shù)據(jù)庫驅(qū)動器，以便 ODBC 函數(shù)調(diào)用，但是數(shù)據(jù)庫驅(qū)動器本身也執(zhí)行 ODBC 函數(shù)調(diào)用，并與數(shù)據(jù)庫相互配合。因此當(dāng)應(yīng)用系統(tǒng)發(fā)出調(diào)用與數(shù)據(jù)源進(jìn)行連接時，數(shù)據(jù)庫驅(qū)動器能管理通信協(xié)議。當(dāng)建立起與數(shù)據(jù)源的連接時，數(shù)據(jù)庫驅(qū)動器便能處理應(yīng)用系統(tǒng)向 DBMS 發(fā)出的請求，對分析或發(fā)自數(shù)據(jù)源的設(shè)計進(jìn)行必要的翻譯，并將結(jié)果返回給應(yīng)用系統(tǒng)。 2 JDBC 的誕生 自從 Java 語言于 1995 年 5 月正式公布以來， Java 風(fēng)靡全球。出現(xiàn)大量的用 java 語言編寫的程序，其中也包括數(shù)據(jù)庫應(yīng)用程序。由于沒有一個 Java 語言的 API，編程人員不得不在 Java 程序中加入 C 語言的 ODBC 函數(shù)調(diào)用。這就使很多 Java 的優(yōu)秀特性無法充分發(fā)揮，比如平臺無關(guān)性、面向?qū)ο筇匦缘?。隨著越來越多的編程人員對 Java 語言的日益喜愛，越來越多的公司在 Java 程序開發(fā)上投入的精力日益增加，對 java 語言接口的訪問數(shù)據(jù)庫的 API的要求越來越強烈。也由于 ODBC 的有其不足之處，比如它并不容易使用，沒有面 向?qū)ο蟮奶匦缘鹊龋?SUN 公司決定開發(fā)一 Java 語言為接口的數(shù)據(jù)庫應(yīng)用程序開發(fā)接口。在 JDK1 x版本中， JDBC 只是一個可選部件，到了 JDK1 1 公布時， SQL 類包（也就是 JDBCAPI）山西大學(xué)本科畢業(yè)論文（設(shè)計）外文翻譯資料 就成為 Java 語言的標(biāo)準(zhǔn)部件。 二、 JDBC 技術(shù)概述 JDBC 是一種可用于執(zhí)行 SQL 語句的 JavaAPI（ ApplicationProgrammingInterface，應(yīng)用程序設(shè)計接口）。它由一些 Java 語言寫的類、界面組成。 JDBC 給數(shù)據(jù)庫應(yīng)用開發(fā)人員、數(shù)據(jù)庫前臺工具開發(fā)人員提供了一種標(biāo)準(zhǔn)的應(yīng)用程序設(shè)計接口，使開發(fā) 人員可以用純 Java 語言編寫完整的數(shù)據(jù)庫應(yīng)用程序。 通過使用 JDBC，開發(fā)人員可以很方便地將 SQL 語句傳送給幾乎任何一種數(shù)據(jù)庫。也就是說，開發(fā)人員可以不必寫一個程序訪問 Sybase，寫另一個程序訪問 Oracle，再寫一個程序訪問 Microsoft 的 SQLServer。用 JDBC 寫的程序能夠自動地將 SQL 語句傳送給相應(yīng)的數(shù)據(jù)庫管理系統(tǒng)（ DBMS）。不但如此，使用 Java 編寫的應(yīng)用程序可以在任何支持 Java 的平臺上運行，不必在不同的平臺上編寫不同的應(yīng)用。 Java 和 JDBC 的結(jié)合可以讓開發(fā)人員在開發(fā)數(shù)據(jù)庫應(yīng)用時 真正實現(xiàn)“ WriteOnce， RunEverywhere！” Java 具有健壯、安全、易用等特性，而且支持自動網(wǎng)上下載，本質(zhì)上是一種很好的數(shù)據(jù)庫應(yīng)用的編程語言。它所需要的是 Java 應(yīng)用如何同各種各樣的數(shù)據(jù)庫連接， JDBC 正是實現(xiàn)這種連接的關(guān)鍵。 JDBC 擴展了 Java 的能力，如使用 Java 和 JDBCAPI 就可以公布一個 Web 頁，頁中帶有能訪問遠(yuǎn)端數(shù)據(jù)庫的 Ap plet。或者企業(yè)可以通過 JDBC 讓全部的職工（他們可以使用不同的操作系統(tǒng)，如 Windwos， Machintosh 和 UNIX）在 Intranet 上連接到幾個全球數(shù)據(jù)庫上，而這幾個全球數(shù)據(jù)庫可以是不相同的。隨著越來越多的程序開發(fā)人員使用 Java 語言，對 Java 訪問數(shù)據(jù)庫易操作性的需求越來越強烈。 MIS 管理人員喜歡 Java 和 JDBC，因為這樣可以更容易經(jīng)濟地公布信息。各種已經(jīng)安裝在數(shù)據(jù)庫中的事務(wù)處理都將繼續(xù)正常運行，甚至這些事務(wù)處理是存儲在不同的數(shù)據(jù)庫管理系統(tǒng)中；而對新的數(shù)據(jù)庫應(yīng)用來說，開發(fā)時間將縮短，安裝和版本升級將大大簡化。程序員可以編寫或改寫一個程序，然后將它放在服務(wù)器上，而每個用戶都可以訪問服務(wù)器得到最新的 版本。對于信息服務(wù)行業(yè)， Java 和 JDBC 提供了一種很好的向外界用戶更新信息的方法。 1 JDBC 的任務(wù) 簡單地說， JDBC 能完成下列三件事： 1）同一個數(shù)據(jù)庫建立連接； 2）向數(shù)據(jù)庫發(fā)送 SQL 語句； 3）處理數(shù)據(jù)庫返回的結(jié)果。 2 JDBC 一種底層的 API JDBC 是一種底層 API，這意味著它將直接調(diào)用 SQL 命令。 JDBC 完全勝任這個任務(wù)，而且比其他數(shù)據(jù)庫互聯(lián)更加容易實現(xiàn)。同時它也是構(gòu)造高層 API 和數(shù)據(jù)庫開發(fā)工具的基礎(chǔ)。高層 API 和數(shù)據(jù)庫開發(fā)工具應(yīng)該是用戶界面更加友好，使用更加方便，更易于理解的。但所有這樣的 API 將最終 被翻譯為象 JDBC 這樣的底層 API。目前兩種基于 JDBC 的高層 API正處在開發(fā)階段。 1） SQL 語言嵌入 Java 的預(yù)處理器。雖然 DBMS 已經(jīng)實現(xiàn)了 SQL 查詢，但 JDBC 要求 SQL語句被當(dāng)作字符串參數(shù)傳送給 Java 程序。而嵌入式 SQL 預(yù)處理器允許程序員將 SQL 語句混用： Java 變量可以在 SQL 語句中使用，來接收或提供數(shù)值。然后 SQL 的預(yù)處理器將把這種Java SQL 混用的程序翻譯成帶有 JDBCAPI 的 Java 程序。 2）實現(xiàn)從關(guān)系數(shù)據(jù)庫到 Java 類的直接映射。 Javasoft 和其他公司已經(jīng)宣布要實現(xiàn)這一技 術(shù)。在這種“對象關(guān)系”映射中，表的每一行都將變成這類的一個實例，每一列的值對應(yīng)實例的一個屬性。程序員可以直接操作 Java 的對象；而存取所需要的 SQL 調(diào)用將在內(nèi)部直接產(chǎn)山西大學(xué)本科畢業(yè)論文（設(shè)計）外文翻譯資料 生。還可以實現(xiàn)更加復(fù)雜的映射，比如多張表的行在一個 Java 的類中實現(xiàn)。 隨著大家對 JDBC 興趣的不斷濃厚，越來越多的開發(fā)人員已經(jīng)開始利用 JDBC 為基礎(chǔ)的工具進(jìn)行開發(fā)。這使開發(fā)工作變得容易。同時，程序員也正在開發(fā)對最終用戶來說訪問數(shù)據(jù)庫更加容易的應(yīng)用程序。 3 JDBC 和 ODBC 及其他 API 的比較 到目前為止，微軟的 ODBC 可能是用得最廣 泛的訪問關(guān)系數(shù)據(jù)庫的 API。它提供了連接幾乎任何一種平臺、任何一種數(shù)據(jù)庫的能力。那么，為什么不直接從 Java中直接使用 ODBC呢？ 回答是可以從 Java 中使用 ODBC，但最好在 JDBC 的協(xié)助下，用 JDBC ODBC 橋接器實現(xiàn)。那么，為什么需要 JDBC 呢？要回答這個問題，有這么幾個方面： 1） ODBC 并不適合在 Java 中直接使用。 ODBC 是一個 C 語言實現(xiàn)的 API，從 Java 程序調(diào)用本地的 C 程序會帶來一系列類似安全性、完整性、健壯性的缺點。 2）其次，完全精確地實現(xiàn)從 C 代碼 ODBC 到 JavaAPI 寫的 ODBC 的翻譯也并不令人滿意。比如， Java 沒有指針，而 ODBC 中大量地使用了指針，包括極易出錯的空指針“ void”。因此，對 Java 程序員來說，把 JDBC 設(shè)想成將 ODBC 轉(zhuǎn)換成面向?qū)ο蟮?API 是很自然的。 3） ODBC 并不容易學(xué)習(xí)，它將簡單特性和復(fù)雜特性混雜在一起，甚至對非常簡單的查詢都有復(fù)雜的選項。而 JDBC 剛好相反，它保持了簡單事物的簡單性，但又允許復(fù)雜的特性。 4） JDBC 這樣的 JavaAPI 對于純 Java 方案來說是必須的。當(dāng)使用 ODBC 時，人們必須在每一臺客戶機上安裝 ODBC 驅(qū)動器和驅(qū)動管理器。如 果 JDBC 驅(qū)動器是完全用 Java 語言實現(xiàn)的話，那么 JDBC 的代碼就可以自動的下載和安裝，并保證其安全性，而且，這將適應(yīng)任何Java 平臺，從網(wǎng)絡(luò)計算機 NC 到大型主機 Mainframe。 總而言之， JDBCAPI 是能體現(xiàn) SQL 最基本抽象概念的、最直接的 Java 接口。它建構(gòu)在 ODBC 的基礎(chǔ)上，因此，熟悉 ODBC 的程序員將發(fā)現(xiàn)學(xué)習(xí) JDBC 非常容易。 JDBC 保持了 ODBC 的基本設(shè)計特征。實際上，這兩種接口都是基于 X OPENSQL 的調(diào)用級接口（ CLI）。它們的最大的不同是 JDBC 是基于 Java 的風(fēng)格和優(yōu)點，并強化了 Java 的風(fēng)格和優(yōu)點。 最近，微軟又推出了除了 ODBC 以外的新的 API，如 RDO， ADO 和 OLEDB。這些API 事實上在很多方面上同 JDBC 一樣朝著相同的方向努力，也就是努力成為一個面向?qū)ο蟮?，基?ODBC 的類接口。然而，這些接口目前并不能代替 ODBC，尤其在 ODBC 驅(qū)動器已經(jīng)在市場完全形成的時候，更重要的是它們只是 ODBC 的“漂亮的包裝”。 4 JDBC 兩層模型和三層模型 JDBC 支持兩層模型，也支持三層模型訪問數(shù)據(jù)庫。 如圖所示，兩層模型中，一個 java Appple 或者一個 JA va 應(yīng)用直接同數(shù) 據(jù)庫連接。這就需要能直接被訪問的數(shù)據(jù)庫進(jìn)行連接的 JDBC 驅(qū)動器。用戶的 SQL 語句被傳送給數(shù)據(jù)庫，而這些語句執(zhí)行的結(jié)果將被傳回給用戶。數(shù)據(jù)庫可以在同一機器上，也可以另一機器上通過網(wǎng)絡(luò)進(jìn)行連接。這被稱為“ Client/Server”結(jié)構(gòu)，用戶的計算機作為 Client,運行數(shù)據(jù)庫的計 算機作為 Server。這個網(wǎng)絡(luò)可是 intranet，比如連接全體雇員的企業(yè)內(nèi)部網(wǎng)，當(dāng)然也可以是internet。 如圖所示，在三層模型中，命令將被發(fā)送到服務(wù)的“中間層”，而“中間層”將 SQL語句發(fā)送到數(shù)據(jù)庫。數(shù)據(jù)庫處理 SQL 語句并 將結(jié)果返回“中間層”，然后“中間層”將它們 返回用戶。 MIS 管理員將發(fā)現(xiàn)三層模型很有吸引力，因為“中間層”可以進(jìn)行對訪問的控制并協(xié)同數(shù)據(jù)庫的更新，另一個優(yōu)勢就是如果有一個“中間層”用戶就可以使用一個易用的高層的 API，這個 API 可以由“中間層”進(jìn)行轉(zhuǎn)換，轉(zhuǎn)換成底層的調(diào)用。而且，在許多情況下，三層模型可以提供更好的性能。 到目前為止，“中間層”通常還是用 C 或 C+實現(xiàn)，以保證其高性能。但隨著優(yōu)化編譯器的引入，將 java 的字節(jié)碼轉(zhuǎn)換成高效的機器碼，用 java 來實現(xiàn)“中間層”將越來越實山西大學(xué)本科畢業(yè)論文（設(shè)計）外文翻譯資料 際。而 JDBC 是允許從一個 java“中間層”訪問數(shù)據(jù)庫的關(guān)鍵。 指導(dǎo)教師評語： 簽字： 年 月 日 JDBC Interface Technology JDBC is a SQL statement can be used for the implementation of the JavaAPI (ApplicationProgrammingInterface Application Programming Interface). It consists of a number of Java Language class and interface components. JDBC for database application developers, database developers Front Desk Tools provides a standard application programming interface, So that developers can use pure Java language to prepare a complete database application. One, ODBC to JDBC course of development Speaking of JDBC, it is tempting to think of another very familiar with the word ODBC. There is no contact between them then? If there is, then between them is What kind of relationship? ODBC is the English abbreviation OpenDatabaseConnectivity. It is a used in related or not related to database management system (DBMS) to access data And implementation using C language, the standard application data interface.通過ODBCAPI, applications can access the stored in a variety of database management system (DBMS) Data, regardless of what the use of each DBMS data storage format and programming interface. 1. ODBC structural model ODBC structure includes four main parts: application program interface, the drive manager, database driver and data source. Application Programming Interface: Shielded different ODBC database drivers the difference between the function call to provide users with a unified SQL programming interface. Driver Manager: In order to load the database application drives. Database drive: implementation of the ODBC function calls to provide data source specific SQL request. If necessary, the database driver will be requested to amend application Order to make the request in accordance with the relevant DBMS supported by the grammar. Data Source: by the user wants to access the data, as well as with its associated operating system, DBMS and the DBMS used to access the network platform. Although the ODBC Driver Manager the main purpose of the database are 山西大學(xué)本科畢業(yè)論文（設(shè)計）外文翻譯資料 loaded drive in order to ODBC function call, but the database itself drive the implementation of ODBC Functions Call, and with the database each other. Thus, when the calling application systems and data sources to connect, the database driver can manage communications protocol. When set up with Data source connectivity, database-driven application system is able to handle the request sent to the DBMS of analysis or data source from the bottom of the design of the necessary translation, and The results back to the applications. 2. JDBC birth Since the Java language in May 1995 has been officially announced, Java swept the world. Emergence of many languages with java program, including the database should be Procedure. Because of absence of a Java language API, the programmer has to program in Java language ODBC add C function call. This makes Java a lot of outstanding Unable to give full play to the characteristics, such as platform independence, object-oriented characteristics. As more and more programmers to the Java language increasingly popular, more and more public Secretary for Program Development in Java on the increasing energy input on the java language interface to access the database of the API requirements become stronger and stronger. Also because of the ODBC has its shortcomings The Department, such as it is not easy to use, there is no object-oriented.features and so on, SUN One company decided to develop Java language database interface application development interface. At JDK1. x version, JDBC is an optional component to theJDK1.1announcement, SQL-type package (that is, JDBCAPI) has become the standard Java language, the Department of Pieces. Second, JDBC Technical Overview JDBC is a SQL statement can be used for the implementation of the JavaAPI (ApplicationProgrammingInterface, Application Programming Interface). It consists of a number of Writing Java language class, interface components. JDBC for database application developers, database developers Front Desk Tools provides a standard Application Programming Access The mouth, so that developers can use pure Java language to prepare a complete database application. Through the use of JDBC, developers can easily send SQL statements to virtually any kind of database. In other words, developers do not have to write a Program Access Sybase, write another program to visit Oracle, write a program to visit Microsofts 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 combination of Java and JDBC allows developers to develop database applications really achieve WriteOnce, RunEverywhere! Java has a robust, secure, easy-to-use 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(xué)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 tranet 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 these matters are stored in different database management systems； and the new database application, the development time will be shortened, installation and version This upgrade will be greatly simplified. Programmers can write or rewrite a program, and then put it on the server, each user can access the server to be up-to-date Version. For the information service industry, Java and JDBC provides a good user to update information to the outside world approach. 1. JDBC-mission Easy to say, JDBC can complete the following three things: 1) set up with a database connection； 2) Send SQL statements to the database； 3) deal with the results of the database back. 2. JDBC-an underlying API JDBC is an underlying API, which means that it will direct calls to SQL commands. JDBC fully qualified for this mission, but also than other database connectivity is more easily Now. It is also constructed at the same time high-level API and database development tools. High-level API and database development tools should be more friendly user interface, the use of more side Then, more easily understandable. However, all this API will eventually be translated into JDBC such as the bottom of API. At present, two high-level API based on JDBC is in development stage Paragraph. 1) SQL language embedded Java pre-processor. While the DBMS has achieved the SQL query, but the JDBC requirements of SQL statements as a string parameter transmitted to the Java way Sequence. The embedded SQL preprocessor allows a programmer to mix SQL statements: Java variables can be used in SQL statements to receive or provide the value. And the pre-SQL This processor will be Java / SQL mix procedures translated into the Java program with JDBCAPI. 2) implementation from the relational database to the Java type of direct mapping. Javasoft and other companies have announced plans to achieve this technology. At this object / relational Mapping table of each line will become an example of this type, each column corresponds to the value of a property instance. Java programmers can directly operate the object； and depositors Check required by the SQL call to be a direct consequence of in-house. Can also achieve more complex mapping, such as tables of many firms of a Java implementation of the class. With the U.S. on the continuing strong interest in JDBC, a growing number of developers 山西大學(xué)本科畢業(yè)論文（設(shè)計）外文翻譯資料 have begun to use JDBC-based tools for development. This development work has become Easy. At the same time, programmers are also being developed for end-users easier access to the database applications. 3. JDBC and ODBC, and other API Comparison So far, Microsofts ODBC may be the most widely used relational database access API. It provides a connection to almost any platform, any one of a few According to the ability of the Treasury. Well, why not directly from Java directly using ODBC it? The answer is available from Java using ODBC, but preferably by the help of JDBC, using JDBC-ODBC bridge implementation. So why does JDBC necessary? To return Answer this question, there are so few aspects: 1) ODBC is not suitable for direct use in Java. ODBC is a C language implementation of the API, from Java program to call the local C procedure will bring about a series of similar security Wide, integrity, robustness shortcomings. 2) Secondly, completely accurate implementation ODBC from C code to the ODBC Writing JavaAPI translation is also not satisfactory. For instance, Java no pointer, and ODBC Medium Substantial use of indicators, including the highly error null pointer void *. Thus, Java programmers, the idea put JDBC to ODBC converted into object-oriented The API is very natural. 3) ODBC is not easy to study, it features easy and complex characteristics of mixed together, even for very simple query options are complex. The JDBC just Instead, it has maintained a simple and easy things, but the characteristics of the complex permit. 4) JDBC such JavaAPI for pure Java programs are necessary. When using ODBC, people must be on each client machine to install ODBC drivers and Driver Manager. If the JDBC driver to use Java language are fully realize, then the JDBC code can be automatically downloaded and installed, and to ensure their safety, Moreover, this will adapt to any Java platform, from the NC network computer to the mainframe Mainframe. All in all, JDBCAPI are able to embody the most basic abstraction of SQL, the most direct Java interface. It is the foundation to build on in the ODBC, therefore, familiar with the ODBC JDBC programmers will find very easy to study. JDBC has maintained the basic design features of ODBC. In fact, these two interfaces are based on X / OPENSQL the call-level access I (CLI). Their biggest difference is that JDBC is based on the style and the advantages of Java and Java has strengthened the style and advantages. Recently, Microsoft also launched ODBC except outside the new API, such as RDO, ADO and OLEDB. These API in fact in many ways, like moving on with the JDBC-phase The same direction, which is striving to become an object-oriented, based on the type of ODBC interface. However, these interfaces is currently no substitute for ODBC, particularly in the ODBC Drive has been in the market, when fully formed, more importantly, they are only ODBCs beautiful packaging. 4. JDBC two-tier model and the thr