【導(dǎo)讀】效率和管理水平，面對(duì)心理健康信息化的發(fā)展趨勢(shì)而設(shè)計(jì)的。2020快速開(kāi)發(fā)工具開(kāi)發(fā)前臺(tái)，采用SQLServer2020數(shù)據(jù)庫(kù)作為后臺(tái)數(shù)據(jù)庫(kù)。次登陸的用戶名和密碼都是學(xué)號(hào)，登陸后可修改密碼，首次登陸需要填寫相關(guān)信息，信息，查看測(cè)試結(jié)果，并對(duì)試題進(jìn)行管理。系統(tǒng)極大的減輕了后臺(tái)管理人員的工作量，提高了學(xué)生的心理健康普查效率。

　　

【正文】 n addition, procedural programming languages would have to use some sort of looping structure to repeat this process on every record. SQL operates on an entire set of records all at the same time. SQL is like haiku for programmers。 often a dozen words or fewer can delete or change thousands of records. Finally, SQL is a plete data definition language (DDL). The database itself can be created along with all tables, fields, primary keys, and relationships. Add to that the record insert mands, and you can have a plete database and all its data expressed in 1 30 programming code. This greatly enhances a database programmer’s ability to work remotely or to port data enhancements among various installations. The prerequisite for learning SQL is knowledge in Discrete Mathematics (Set Theory,Relations and Functions). Although it is not necessary to learn all the theorems and proof for the theorems in the Discrete Mathematics, you should have learned the basic concepts of the Sets, Relations and Functions. This will help you to learn SQL queries and fundamentals easily. If you want to explore a RDBMS more deeply you should learn Graph Theory too. Although I tried to avoid SQL Server specific topics in this article, I am sure that some topics are pure to SQL server such as SQL Enterprise manager. Data to DBMS Data is something that should be stored for future manipulations (In terms of Database). The system which provides such a facility is called Database Management System or DBMS. The simplest form to store a data for latter retrieval is using a text file. For example you may want to store your friends name and phone numbers to use it latter. (In this case you may use notepad or word to do so.) This kind of storage is called flat file storage or unstructured storage. In this case the text editor uses the File and Directory services provided by the Operating System to acplish the task of storing and retrieving data. But these unstructured flat files are not suitable to large data such as storing stock details. Since the stock data is large in volume and added and updated frequently it is not scale up well if we use a simple flat file. To overe this we need some system which should perform the storing, retrieving, manipulating and querying operations on the data and give output to us. This kind of system is called Database Management System. So a DBMS is a system which anizes and stores data in a structural way for fast retrieval. A DBMS uses one or more files to store the given data. Since the DBMS is meant mainly for developers every DBMS has it is own language to write the mands. The languages are standardized under the name SQL(Structured Query Language). The following definition for SQL is from Books Online“A language used to insert, retrieve, modify, and delete data in a relational also contains statements for defining and administering the objects in a database. SQL is the language 31 supported by most relational databases, and is the subject of standards published by the International Standards Organization (ISO)and the American National Standards Institute (ANSI). SQL Server 2020 uses a version of the SQL language called TransactSQL.” Representation of Data by DBMS DBMS should represent the data stored by them in some form and it is most mon to represent them as Column, Row, Tables and Databases. As you know SQL you know what are columns, rows, tables and database. Primary Key A column or set of columns used to uniquely identify the records in a table. Primary Keys don’t allow NULL values. You can relate a table with other table if you have defined primary on it. (So defining UNIQUE and NOT NULL constraint is not equivalent to primary key). SQL server will create a Clustered index while you create a primary key. Primary keys should be carefully defined since based on it other relations are defined. Poorly designed primary keys will affect insert, update and delete operations. Primary keys are different from which are used for paperwork. Foreign Key The primary key of one of the tables is almost always involved in the relationship. The field in the other table on the other end of that relationship is called the foreign key. The term simply refers to the fact that this field is key to relating to a foreign (or other) table. In the Lyric Music database there is a relationship between artists and titles. The ArtistID field is the primary key in the Artists table. Therefore, the ArtistID field in the Titles table is a foreign key. It relates the Titles table to the primary key in the Artists table. Most table relationships can be described as onetomany. In a onetomany relationship, a single record in the first table can be related to many records in the second table. However, each record in the second table relates to only one record in the first table. In addition to onetomany relationship, tables can have onetoone relationships. But these are much less mon. Server – Client In Client Server technology, a server is a program which does all the jobs that is requested by the client and Client is a program which depends on the Server to acplish 32 its task. Client is mainly used to interact with Users and most Server software doesn’t have direct interaction with Users. A DBMS should have the following functionality – Interaction with users (developers),Managing Data. Since these two functionalities are entirely different modern DBMS is divided into two or more parts. Almost all current DBMS has the following module –Server and one or more clients. A server module is program which manages the data and handles requests from the client applications. It interprets the SQL queries and returns results back to the clients. A client program is a program which sends