计算机专业英语-(第2版)

Unit 5Database[1]Text AMySQL IntroductionThe MySQL database system uses a client/server客户端/服务器 architecture体系，模式 that centers on the server. The server is the program that actually manipulates操作；操纵 databases. Client programs dont do that directly. Instead, they communicate your intent意图；目的 to the server by means of statements语句，命令 written in Structured Query Language结构化查询语言 (SQL). Client programs are installed locally on the machine from which you want to access MySQL, but the server can be installed anywhere, as long as clients can connect to it.注1 MySQL is an inherently与生俱来地 networked database system, so clients can communicate with a server that is running locally on your machine or one that is running somewhere else, perhaps on a machine on the other side另一侧，另一端 of the planet. Clients can be written for many different purposes, but each interacts互相影响 with the server by connecting to it, sending SQL statements to it to have database operations performed, and receiving the statement results from it. One such client is the MySQL program that is included in MySQL distributions分配；分布. When used interactively, MySQL prompts you for a statement, sends it to the MySQL server for execution, and then displays展示；显示 the results.注2 This capability makes MySQL useful in its own right, but its also a valuable tool to help you with your MySQL programming activities. Its often convenient to便捷的；方便的 be able to quickly review the structure of a table that youre accessing from within a script手迹；脚本, to try a statement before using it in a program to make sure that it produces the right kind of output, and so forth等等. MySQL is just right for these jobs. MySQL also can be used noninteractively; for example, to read statements from a file or from other programs. This enables you to use MySQL from within scripts or cron时钟守护进程 jobs or in conjunction同时发生 with other applications. This chapter describes MySQLs capabilities so that you can use it more effectively:  Starting and stopping MySQL  Specifying connection parameters参数；系数 and using option files  Setting your PATH variable so that your command interpreter解释器 can find MySQL (and other MySQL programs)  Issuing SQL statements interactively交互式地 and using batch files  Canceling and editing statements  Controlling控制；管理 MySQL output format To use the examples shown, youll need a MySQL user account and a database to work with. The first two sections of the chapter describe how to use MySQL to set these up. For demonstration示范；演示 purposes, the examples assume假定 that youll use MySQL as follows:  The MySQL server is running on the local host  Your MySQL username and password are cbuser and cbpass  Your database is named cookbook For your own experimentation实验；试验, you can violate违反 any of these assumptions. Your server need not be running locally, and you need not use the username, password, or database name that are used in this charpter.注3 Naturally, if you use different default values on your system, youll need to change the examples accordingly. Even if you do not use cookbook as the name of your database, I recommend that you create a database to be dedicated专用的 specifically to trying the examples shown here, rather than trying them with a database that youre using currently for other purposes.注4 Otherwise, the names of your existing tables may conflict with those used in the examples, and youll have to make modifications to the examples that are unnecessary when you use a separate database. If you have another favorite client program to use for issuing queries, some of the concepts covered in this chapter may not apply. For example, you might prefer the graphical MySQL Query Browser program, which provides a pointandclick interface to单击鼠标接口 MySQL databases. In this case, some of the principles will be different, such as the way that you terminate结束，终止 SQL statements. In MySQL, you terminate statements with semicolon (;) characters, whereas in MySQL Query Browser浏览器 there is an Execute button for terminating statements.注5 Another popular interface is phpMyAdmin, which enables you to access MySQL through your web browser