Summary of data center reconstruction (Layer 3)

It took two months to complete the three-tier IDC reconstruction. During this period, the SQL software did not work with each other, resulting in various repairs and gained the "wonderful" experience of the hacker, finally, after several times of uninstallation, the system is reinstalled inevitably. The time spent on SQL in the past two months has been less than a week. Looking back, grindstone only took 50 hours to rebuild a single data center. In an instant, there was a feeling of being hurt by SQL. Others were working on the system. I was ...... Played computer. So now, with the big significance that a strong man will die, let the data center charge an early day.

The restructuring of the data room charging system involves four aspects: business logic, database, hierarchy, and control.

Business Logic

Here, the business logic refers to the functional design of the "Data room Charging System", which is also a problem we often say that there are several lines that are just a few business logic. Before starting, it is best to analyze the lines it has and roughly plan the sequence of implementation of each line, from easy to difficult. This process needs to be reflected in UML, and it is also the key to macro control for knock-on systems. In the IDC room, the complicated ones are on and off the server, combined query, and checkout. I drew a detailed process before I was about to do so, which is very fast. This part is simple as long as the ideas are clear and reasonable.

Database

For the first time, the Data Center was built in imitation of the databases in the data, which is a little troublesome to use. I learned some database design principles in "database system principles". This time it came in handy. At the beginning, I came from the several paradigms and found that something was wrong during the system knock process, being too concise is not conducive to the use of the system. It is almost the same to satisfy the three paradigms. Database design involves database tables, database relationship graphs, views, and stored procedures, which were summarized in previous blogs. (If you want to map the image, the SQL cannot be opened again. Wait until it is ready)

Layered

Layers and design patterns should be put together, which is also the top priority of Data Center reconstruction. However, since I have not yet added a design pattern, now I will briefly summarize the three layers of U, B, and D.

The U layer is the form interface layer, which is divided by form. It is troublesome to use some controls, so it is separately divided into one aspect.

Layer B is an intermediary between the U and D layers. It is the simplest layer for transmitting information by function division.

Layer D deals with databases. It is the soul of the system to manipulate databases based on the information transmitted from layer B, divided by database tables. The added sqlhelper plays an important role in the D layer, making the D Layer more conducive to management.

The E layer is equivalent to a global variable. It is divided by database tables and views, that is, there are entities in any table in the database, whether it is a real table or a virtual table. The conversion between the e-layer and D-layer is implemented by a converthelper class encapsulated in the e-layer.

Widget

The transformation from VB to VB.net has not changed much in programming style, but the main controls have been studied, from menu controls, table controls to label controls, it was difficult to use VB.net before it was used. Controls to be understood in the IDC: Table Control datagridview, Menu Control menustrip, label control tabcontrol, report control reportviewer, time control datetimepicker, and browser control webbrowser. Among them, the datagridview and reportviewer are mostly used. As described in subsequent blogs, it is easy to know that you can use them. Add some common control attributes that are incorrect at the beginning:

Form: the default acceptbutton button and the cancelbutton cancel button. The default and cancel buttons in VB are placed on the control and moved to the form in VB.net.

Text control: Locked lock location, readonly read-only, multiline allows you to adjust the control size, vbcrlf = CHR (13) & CHR (10) is the carriage return line break.

ComboBox control: the display type of the dropdownstyle drop-down box. Only the content in the drop-down list can be selected.

 

 

 

 

 

Summary of data center reconstruction (Layer 3)