record。 It includes students of the school, name, sex, nationality, date of birth, performance data items。 These data items can be pided into two types : one called early such as student gender, origin, etc。, these data were no longer pided in data processing, the smallest units; Another called portfolio, the performance of students who, it can be pided into mathematics, physics, chemistry and other smaller items。 Normally, in addressing the question of the practical application of each student is recorded as a basic unit for a visit and treatment。 

Data objects (Data Object) or data element type (Data Element Class) is the nature of the data elements with the same pool。 In a specific issue, the data elements have the same nature (not necessarily equal value elements), belonging to the same data objects (data element type), the data element is an example of such data elements。 For example, traffic information systems in the transportation network, is a culmination of all the data elements category, peak a and B each represent an urban middle is the data elements of the two types of examples of the value of their data elements a and B respectively。   

Data structure (Data Structure) refers to the mutual relationship that exists between one or more data elements together。 In any case, between data elements will not be isolated in between them exist in one way or another, such as the relationship between the data element structure。 According to the data elements of the relationship between different characteristics, usually have the following four basic categories of the structure :   

1 assembly structures。 In the assembly structure, the relationship between data elements is "belonging to the same pool。" Assembly elements relations is a very loose structure。   

2 linear structures。 The structure of the data elements exist between one-to-one relationship。   

3 tree structure。 The structure of the data elements exist between hierarchical relationship。   

4graphics structure。 The structure of the data elements of the relationship that existed between Duoduiduo, graphics structure also known as network structure。 

C++Builder programming experience 一、Database programming 

And the use of Delphi, Borland C++Builder BDE (Borland   Database Engine) database interface, in particular its use BDE Administrator unified management database alias, the database operation has nothing to do with the location of the database documents, thus enabling database development easier operation。 But in a database application procedures at the same time we have to "release" BDE, the database for some simple procedures may BDE than our own design procedures big, but as the use of BDE InstallShield, add database alias is likely allocation failure。 Therefore, we can use the following methods : still in the design stage procedure using BDE alias management database for debugging, but in procedures substantially (as in the main Chuangti OnCreate event processing function) to Table components DatabaseName attributes, such as the use of similar phrases as follows :   Table1->DatabaseName = ExtractFilePath (Application->ExeName); Or Table1->DatabaseName   = ExtractFilePath (Application->ExeName+ "DB"); 

Thus, no impact on the debugging phase, will be issued if the application procedures Table1 document on the use of databases or their current catalogue "DB" virus, database procedures can be normal operation。 You can even be a database to catalogue the documents in the form of character string Register (installed in the installation process), then the procedure in the acquisition of substantially from the catalogue of payrolls, Fuzhi DatabaseName attribute to be。 Anyway, you do not need to install relatively large BDE forced users。