Last week's internship report-, internship report-2014

Last week's internship report-, internship report-2014

Two important issues

1. Why does the company's database not need stored procedures and Foreign keys?

I did not answer this question. I came back and found a good answer on the Internet.

{

1: in a large number of cases, the use of foreign key constraints will lead to poor performance. Do not think about foreign keys on the Internet. It is best not to use table connection queries.
2: horizontal table segmentation when the data volume is large, such as foreign key constraints, triggers, and stored procedures are restricted areas
3: Data integrity is a business requirement. Therefore, it must be controlled by applications at the business layer.
4: Foreign keys can lead to very chaotic table structures, and almost cannot be moved. A layer-by-layer foreign key constraint may lead to cyclic constraints in many situations of tables.

}

2. Why should I use interfaces in the business logic layer?

The business logic required by the Controller is injected by the constructor. The original code does not need to be modified when the new business logic is replaced.