1. Introducing dependencies in Maven
2. Use of pagination in code
3. Source code analysis
PageHelper.startPage(page,pageSize);
Sets the page number and the number of pages to display on each page
View the source code PageInterceptor class, the implementation of the Interceptor interface
An Interceptor interface overrides the following three methods
Interceptors are defined to intercept Executor’s Query methods
The interceptor fires when the following query is executed
List<Map<String, Object>> list = detailMapper.findCourseCredits(studentCode);
Our paging logic is in the Intercept method, which is executed by the interceptor trigger
Query the total number of records first, then query the current page records
4. Performance optimization
When querying the total number of records will query all the fields, when the amount of data will lead to a very slow query speed, normally we query the total number should only query a primary key field on the line, we view the source code found
Add a findCourseCredits_COUNT query to mapper
Debug the total number of query records as written in mapper