At present, the application system based on the relational database is everywhere, it can provide a powerful data query function is an important consideration metric for these system advantages. Many large database applications have their own querier. Such as UF, SAP, etc. But their queriers are only used in their own systems.
I have no sound on a day, and there is a clue of Sangdong play, the birth of the Datagetter querier is born. Even for the ordinary users of the application system, non-IT technicians are also designed, it is necessary to assume that the user does not understand the base table structure and does not understand any SQL statement.
Fighting in January, there is a small completion, but I don't dare to hide, I will show the public, if I have an enlightenment to people, I am very happy!
Basic concept definition
Business object:
It is already in the definition of the original database. The base table in the database can be generally divided into two categories, and one is to define entities (objects), and the other is used to define the relationship between entities (objects). A class of business objects must find the corresponding base table definition. Each record in the base table represents a specific business object definition.
feature:
A feature reflects the characteristics of an object. Features have the characteristics of transmitting and aggregating through an object relationship. The characteristics are divided into narrow feature and general characteristics.
Narrow feature:
A narrow feature is the direct characteristics of an object. Each business field of each base table in the original database is characterized, or a basic feature.
General feature:
In addition to narrow feature, an object includes all features and related derivative features obtained by passing rules and aggregation rules.
Passing rules:
For objects A and B, if the object relationship between it is N: 1, the features of B can be said to a, i.e., the features of the features of B.
Convergence rules:
For objects A and B, if the relationship is 1: N, the feature referred to as B is called a feature of A.
Derivative characteristics: new features of the performance by one or more features in a single line record via a fixed calculation, and derived features, also known as derived features. This feature and aggregation feature is usually not directly present in the original database, but to perform specialized programming. Therefore, it is good to support these two features that it is to determine an important condition that is powerful or not.
Based on the above concept, the user can be used to take such definitions in this definition: it is the process of user obtaining the interest of the object of interest. For example, a contract administrator needs a certain contract's implementation data, including contract signing date, contractor name, total contract amount, accumulated cost, accumulated completion of engineering volume, cumulative cost this year, this year's cumulative project Quantity and other information. In this example, a contract becomes a user's attention, and the contract signing date, which has become the focus of the attention object. In these characteristics, the contract is signed, the contractor name, the total contract amount belongs to the basic characteristics, and the cost of accumulating costs, accumulating the engineering volume, the cost of the year, this year, the accumulated engineering volume belongs to the derived characteristics.
In summary, we can know that the features needed by the user may be in a base table, and it is possible to scatter in different base tables. This is the key and difficulty of data querier development, and two-layer structure based on business object-feature methods happens to solve this problem.
The above is an even developed the theoretical basis for Datagetter. Datagetter The user hides the structure information of the database to directly exhibit business objects and all its business features to users in two-layer structures. Users can get all related features to find business objects without considering it in which base table is scattered in the database. This greatly facilitates the number of users. At the same time, the software also provides an expandable derivative computing method library, aggregation calculation method library, and users have new feature needs, simply register in the corresponding table according to the specified table. If you encounter a particular demand, you can meet the needs by expanding the relevant method libraries. The following information is further explained to further describe the actual working principle of the development of the data querier method based on the business object-characteristic two-layer structure method.
Introduction
(1) System frame map
(2) Software use example demonstrates the illusion scenario: an information system contains a contract management system with basic information of the registration contract, and records the functions of each payment of the contract. The original database base structure of the system is as follows.
A business person wants to obtain the relevant situation of contracts and execution in 2003, the specific content is: contract code, contract name, contract signed date, contract contractor name, contract amount, contract accumulated payment amount. In such an alien example, the base table of the control above can know that the payment of this focus is the contract, and the contract code, the contract, the contract, the contract, and the basic characteristics of the contract. Contract contractor name
Transfer characteristics, and the contract accumulated payment amount is aggregation feature. The completion process description of this query requirement and the illustration are as follows.
Step 1: Select the object category of interest because the contract object is in the contract file cabinet, thus select the contract file cabinet. Then click Next.
The second step is to select the characteristics of interest. It should be noted that the cumulative payment amount required by the user has appeared in the feature list, because the user has been registered in the feature table, so the user only needs to use and does not need to consider how to complete the calculation of the accumulated value. After selecting, click Next.
The third step is to define the object filtering criteria. Filtering conditions can be defined by mice or directly in the condition definition box.
The fourth step is to launch the DataGetter Software to take a number of engine. This step is only a click completion key. A little completed the startup work of the number of engines.
The fifth step is to view the number of extracts and other operations can be made, and the results of this case are as follows. Datagetter Software provides a function of viewing and printing within the system, while saving the results as TXT format files. Using this feature can read the number of extracts in other table processing software such as Excel, it is easy to analyze, process, print, etc.
(3) Datagetter Software Features
1. It is prepared using advanced Java language.
2. A variety of databases can be supported.
3. The end user's zero database knowledge requirement.
4. End users' zero operation training.
5. The end user's zero user programming.
6. Proven data that exists in multi-tables.
7. Number speed is fast.
8. The system provides an expandable multi-line operation method library (such as accumulated, average, etc.). Users can make multiple lines of operational result data as making other basic data, without the need to use an operational function.
9. The system provides an expandable export method library (generating new meaningful data by existing data, such as date data can export year data).
10. The system provides an expandable relationship operation method library.
11. The system provides an expandable feature library.
12. The system can store data extraction results as a text format. To meet the user to complete further processing, typography, printing, etc. need to transfer data extraction results into the special table processing software such as Excel.
13. You can browse the extraction results in the system in the system.
14. The system provides a function of quick print extraction results.
