PageHelper use summary

MyBatis Pagination Plugin-PageHelper

Source code

• Mybatis-PageHelper
• Spring Boot integrates MyBatis, paging plug-in PageHelper, general Mapper

Basic dialect information

• In the PageAutoDialect class, first add the executed dialect class to dialectAliasMap, such as:

registerDialectAlias("mysql", MySqlDialect.class);

• According to the database configuration URL, get the corresponding dialect

private String fromJdbcUrl(String jdbcUrl) {
    
    
    final String url = jdbcUrl.toLowerCase();
    for (String dialect : dialectAliasMap.keySet()) {
    
    
        if (url.contains(":" + dialect.toLowerCase() + ":")) {
    
    
            return dialect;
        }
    }
    return null;
}

Pagination

• Official website document

//第六种，ISelect 接口方式
//jdk6,7用法，创建接口
Page<User> page = PageHelper.startPage(1, 10).doSelectPage(new ISelect() {
    
    
    @Override
    public void doSelect() {
    
    
        userMapper.selectGroupBy();
    }
});
//jdk8 lambda用法
Page<User> page = PageHelper.startPage(1, 10).doSelectPage(()-> userMapper.selectGroupBy());

//也可以直接返回PageInfo，注意doSelectPageInfo方法和doSelectPage
pageInfo = PageHelper.startPage(1, 10).doSelectPageInfo(new ISelect() {
    
    
    @Override
    public void doSelect() {
    
    
        userMapper.selectGroupBy();
    }
});
//对应的lambda用法
pageInfo = PageHelper.startPage(1, 10).doSelectPageInfo(() -> userMapper.selectGroupBy());