SQL AND SQL SERVER
IBM invented a computer language back in the 1970s designed specifically for database queries called SEQUEL；those letters stand for Structured English Query Language．Over time，the language has been added to so that it is not just a language for queries，but can also build databases and manage the database engine’s security．IBM released SEQUEL into the public domain，where it became known as SQL．Because of this heritage you can pronounce it“sequel”or spell it out“S-Q-L．”There are various versions of SQL used in today’s database engines．Microsoft SQL Server uses a version called Transact-SQL，or T-SQL，which stands for Transaction SQL．
1．What Is SQL Server?
SQL Server is a client／server relational database management system（RDBMS）that uses Transact-SQL to send requests between a client and SQL Server．
2．Client／Server Architecture
The terms client，server，and client / server can be used to refer to very general concepts or to specific items of hardware or software．At the most general level，a client is any component of a system that requests services or resources from other components of a system．A server is any component of a system that provides services or resources to other components of a system．
For example，when you print a document from your workstation on a network，the workstation is the client and the machine that does the print spooling is the server．[1]
Any client／server data-based system consists of the following components：
• The server一A collection of data items and supporting objects organized and presented to facilitate services，such as searching，sorting，recombining，retrieving，updating，and analyzing data．The database consists of the physical storage of data and the database services．All data access occurs through the server；the physical data is never accessed directly by the client．
．The client — A software program that might be used interactively by a person or that could be an automated process．This includes all software that interacts with the server，either requesting data from or sending data to the database．Examples are management utilities（those that are part of the SQL Server product as well as those bought separately），ad hoc query and reporting software，custom applications，off-the-shelf applications，and Web server-based applications．[2]
• The communication between the client and the server一The communication between the client and the server depends largely on how the client and server are implemented．Both physical and logical layers of communication can be identified．[3]
When you communicate with someone using the telephone，the telephone system is the physical layer and a spoken natural language is the logical layer of communication．For a data-based system，the physical layer can be a network if the server and the client are on different computers．It can be interprocess communication if the server and the client are on the same computer．The logical communication structure of the physical layer may be low-level operating system calls，a proprietary data access language，or the open structured query language（SQL）．
3．SQL Server Platforms
SQL Server runs on the operating systems shown in Fig. 7-4．The SQL Server version 7 server software runs only on the Windows 32-bit API-based operating systems，but you can use all of the operating system platforms to create and execute client applications．
SQL和SQL服務(wù)器
IBM在20世紀(jì)70年代，設(shè)計(jì)了一種專門處理數(shù)據(jù)庫查詢的計(jì)算機(jī)語言SEQUEL，這幾個(gè)字母是結(jié)構(gòu)化英語查詢語言的縮寫。隨著時(shí)間的推移，它增加了許多功能，就不僅是一個(gè)查詢語言了，還可以創(chuàng)建數(shù)據(jù)庫，管理數(shù)據(jù)庫引擎的安全。IBM把它公開發(fā)行，于是就變成了現(xiàn)在為大家所知的SQL。由于歷史的原因SQL可以讀成sequel，也可以逐字段拼成S-Q-L。在現(xiàn)在的數(shù)據(jù)庫引擎里，已經(jīng)有了好多種SQL版本。微軟SQL server使用的是T-SQL，它代表的是事務(wù)SQL。
1．什么是SQL Server?
SQL Server是一個(gè)客戶機(jī)／服務(wù)器關(guān)系型數(shù)據(jù)庫管理系統(tǒng)（RDBMS），它使用事務(wù)SQL在客戶機(jī)和SQL服務(wù)器間傳送請(qǐng)求。
2．客戶機(jī)一服務(wù)器體系結(jié)構(gòu)
術(shù)語客戶機(jī)、服務(wù)器和客戶機(jī)一服務(wù)器可以是非常廣的概念或?qū)Ｖ赣布?、軟件。按最一般的概念，客戶機(jī)是從系統(tǒng)其他部件請(qǐng)求服務(wù)或資源的系統(tǒng)的任何部件；服務(wù)器是向系統(tǒng)其他部件提供服務(wù)或資源的任何部件。
例如，當(dāng)用戶從網(wǎng)絡(luò)上的工作站打印一個(gè)文件時(shí)，工作站是客戶機(jī)，用作假脫機(jī)打印的機(jī)器是服務(wù)器。
任何基于數(shù)據(jù)的客戶機(jī)、服務(wù)器系統(tǒng)都由下列部件組成。
服務(wù)器--數(shù)據(jù)項(xiàng)和支持對(duì)象的匯集，其中這些對(duì)象是有組織的，并隨時(shí)準(zhǔn)備提交，以便為數(shù)據(jù)的搜索、分類、重組、檢索、更新和分析之類的服務(wù)提供便利。數(shù)據(jù)庫由數(shù)據(jù)的物理存儲(chǔ)器和數(shù)據(jù)庫服務(wù)組成。所有的數(shù)據(jù)訪問都通過服務(wù)器進(jìn)行，客戶機(jī)一概不能直接訪問物理數(shù)據(jù)。
客戶機(jī)－－一個(gè)軟件程序，該程序應(yīng)該由個(gè)人交互使用或可能是一個(gè)自動(dòng)進(jìn)程。其中包括從數(shù)據(jù)庫請(qǐng)求數(shù)據(jù)，或向數(shù)據(jù)庫送數(shù)的與服務(wù)器交互作用的所有軟件，例如管理實(shí)用程序（這些是SQL服務(wù)器產(chǎn)品的一部分并且是單獨(dú)購買的）、特別查詢和報(bào)告軟件、客戶應(yīng)用程序、現(xiàn)貨應(yīng)用程序和基于Web服務(wù)器的應(yīng)用程序。
客戶機(jī)和服務(wù)器之間的通信--客戶機(jī)和服務(wù)器之間的通信在很大程度上取決于客戶和服務(wù)器是如何實(shí)現(xiàn)的。通信的物理層和邏輯層可能是一樣的。
當(dāng)你用電話與某人通信時(shí)，電話系統(tǒng)是物理層，所講的自然語言是通信的邏輯層。對(duì)于基于數(shù)據(jù)的系統(tǒng)，如果服務(wù)器和客戶在不同的計(jì)算機(jī)上，則物理層可以是網(wǎng)絡(luò)。如果服務(wù)器和客戶在同一臺(tái)計(jì)算機(jī)上，則通信可在進(jìn)程之間進(jìn)行。物理層邏輯通信結(jié)構(gòu)可以是低層操作系統(tǒng)調(diào)用，一種專用數(shù)據(jù)訪問語言或開放的結(jié)構(gòu)化查詢語言（SQL）。
3．SQL Server平臺(tái)
SQL服務(wù)器運(yùn)行在如圖7- 4所示的操作系統(tǒng)上。SQL Server第7版服務(wù)器軟件只運(yùn)行在32位的基于API的Windows操作系統(tǒng)上，但可以使用所有的操作系統(tǒng)平臺(tái)去創(chuàng)建和執(zhí)行客戶應(yīng)用程序。
下表給出了操作系統(tǒng)及它們?nèi)绾沃С只虿恢С諷QL Server 7的更多細(xì)節(jié)
IBM invented a computer language back in the 1970s designed specifically for database queries called SEQUEL；those letters stand for Structured English Query Language．Over time，the language has been added to so that it is not just a language for queries，but can also build databases and manage the database engine’s security．IBM released SEQUEL into the public domain，where it became known as SQL．Because of this heritage you can pronounce it“sequel”or spell it out“S-Q-L．”There are various versions of SQL used in today’s database engines．Microsoft SQL Server uses a version called Transact-SQL，or T-SQL，which stands for Transaction SQL．
1．What Is SQL Server?
SQL Server is a client／server relational database management system（RDBMS）that uses Transact-SQL to send requests between a client and SQL Server．
2．Client／Server Architecture
The terms client，server，and client / server can be used to refer to very general concepts or to specific items of hardware or software．At the most general level，a client is any component of a system that requests services or resources from other components of a system．A server is any component of a system that provides services or resources to other components of a system．
For example，when you print a document from your workstation on a network，the workstation is the client and the machine that does the print spooling is the server．[1]
Any client／server data-based system consists of the following components：
• The server一A collection of data items and supporting objects organized and presented to facilitate services，such as searching，sorting，recombining，retrieving，updating，and analyzing data．The database consists of the physical storage of data and the database services．All data access occurs through the server；the physical data is never accessed directly by the client．
．The client — A software program that might be used interactively by a person or that could be an automated process．This includes all software that interacts with the server，either requesting data from or sending data to the database．Examples are management utilities（those that are part of the SQL Server product as well as those bought separately），ad hoc query and reporting software，custom applications，off-the-shelf applications，and Web server-based applications．[2]
• The communication between the client and the server一The communication between the client and the server depends largely on how the client and server are implemented．Both physical and logical layers of communication can be identified．[3]
When you communicate with someone using the telephone，the telephone system is the physical layer and a spoken natural language is the logical layer of communication．For a data-based system，the physical layer can be a network if the server and the client are on different computers．It can be interprocess communication if the server and the client are on the same computer．The logical communication structure of the physical layer may be low-level operating system calls，a proprietary data access language，or the open structured query language（SQL）．
3．SQL Server Platforms
SQL Server runs on the operating systems shown in Fig. 7-4．The SQL Server version 7 server software runs only on the Windows 32-bit API-based operating systems，but you can use all of the operating system platforms to create and execute client applications．
SQL和SQL服務(wù)器
IBM在20世紀(jì)70年代，設(shè)計(jì)了一種專門處理數(shù)據(jù)庫查詢的計(jì)算機(jī)語言SEQUEL，這幾個(gè)字母是結(jié)構(gòu)化英語查詢語言的縮寫。隨著時(shí)間的推移，它增加了許多功能，就不僅是一個(gè)查詢語言了，還可以創(chuàng)建數(shù)據(jù)庫，管理數(shù)據(jù)庫引擎的安全。IBM把它公開發(fā)行，于是就變成了現(xiàn)在為大家所知的SQL。由于歷史的原因SQL可以讀成sequel，也可以逐字段拼成S-Q-L。在現(xiàn)在的數(shù)據(jù)庫引擎里，已經(jīng)有了好多種SQL版本。微軟SQL server使用的是T-SQL，它代表的是事務(wù)SQL。
1．什么是SQL Server?
SQL Server是一個(gè)客戶機(jī)／服務(wù)器關(guān)系型數(shù)據(jù)庫管理系統(tǒng)（RDBMS），它使用事務(wù)SQL在客戶機(jī)和SQL服務(wù)器間傳送請(qǐng)求。
2．客戶機(jī)一服務(wù)器體系結(jié)構(gòu)
術(shù)語客戶機(jī)、服務(wù)器和客戶機(jī)一服務(wù)器可以是非常廣的概念或?qū)Ｖ赣布?、軟件。按最一般的概念，客戶機(jī)是從系統(tǒng)其他部件請(qǐng)求服務(wù)或資源的系統(tǒng)的任何部件；服務(wù)器是向系統(tǒng)其他部件提供服務(wù)或資源的任何部件。
例如，當(dāng)用戶從網(wǎng)絡(luò)上的工作站打印一個(gè)文件時(shí)，工作站是客戶機(jī)，用作假脫機(jī)打印的機(jī)器是服務(wù)器。
任何基于數(shù)據(jù)的客戶機(jī)、服務(wù)器系統(tǒng)都由下列部件組成。
服務(wù)器--數(shù)據(jù)項(xiàng)和支持對(duì)象的匯集，其中這些對(duì)象是有組織的，并隨時(shí)準(zhǔn)備提交，以便為數(shù)據(jù)的搜索、分類、重組、檢索、更新和分析之類的服務(wù)提供便利。數(shù)據(jù)庫由數(shù)據(jù)的物理存儲(chǔ)器和數(shù)據(jù)庫服務(wù)組成。所有的數(shù)據(jù)訪問都通過服務(wù)器進(jìn)行，客戶機(jī)一概不能直接訪問物理數(shù)據(jù)。
客戶機(jī)－－一個(gè)軟件程序，該程序應(yīng)該由個(gè)人交互使用或可能是一個(gè)自動(dòng)進(jìn)程。其中包括從數(shù)據(jù)庫請(qǐng)求數(shù)據(jù)，或向數(shù)據(jù)庫送數(shù)的與服務(wù)器交互作用的所有軟件，例如管理實(shí)用程序（這些是SQL服務(wù)器產(chǎn)品的一部分并且是單獨(dú)購買的）、特別查詢和報(bào)告軟件、客戶應(yīng)用程序、現(xiàn)貨應(yīng)用程序和基于Web服務(wù)器的應(yīng)用程序。
客戶機(jī)和服務(wù)器之間的通信--客戶機(jī)和服務(wù)器之間的通信在很大程度上取決于客戶和服務(wù)器是如何實(shí)現(xiàn)的。通信的物理層和邏輯層可能是一樣的。
當(dāng)你用電話與某人通信時(shí)，電話系統(tǒng)是物理層，所講的自然語言是通信的邏輯層。對(duì)于基于數(shù)據(jù)的系統(tǒng)，如果服務(wù)器和客戶在不同的計(jì)算機(jī)上，則物理層可以是網(wǎng)絡(luò)。如果服務(wù)器和客戶在同一臺(tái)計(jì)算機(jī)上，則通信可在進(jìn)程之間進(jìn)行。物理層邏輯通信結(jié)構(gòu)可以是低層操作系統(tǒng)調(diào)用，一種專用數(shù)據(jù)訪問語言或開放的結(jié)構(gòu)化查詢語言（SQL）。
3．SQL Server平臺(tái)
SQL服務(wù)器運(yùn)行在如圖7- 4所示的操作系統(tǒng)上。SQL Server第7版服務(wù)器軟件只運(yùn)行在32位的基于API的Windows操作系統(tǒng)上，但可以使用所有的操作系統(tǒng)平臺(tái)去創(chuàng)建和執(zhí)行客戶應(yīng)用程序。
下表給出了操作系統(tǒng)及它們?nèi)绾沃С只虿恢С諷QL Server 7的更多細(xì)節(jié)