Final summary of addition, deletion, modification and query

One 、 increase insert（ New data / Put in storage ）

1、 law ：

All are Submitted by the entire user in the browser form The form data Encapsulated in the js Object to pass parameters , stay controller Layer connection （user） The object is connected to
Be careful ：1、sql The statement did not where Conditions （ New data none id, Only after the addition is completed id You can use ）
2、

2、 Different frame writing

1）mybatis Method

1> How to write the mapping file

service Layer interface
service Layer interface implementation class
mapper Layer interface

2> Annotation method

service Layer interface
service Layer interface implementation class
mapper Layer interface

Two 、 Delete delete（ Data deletion ）

A parameter is passed from the front end

3、 ... and 、 Change update（ Data modification ）

Four 、 check select（ Data query ）