性能分析插件、条件构造器、代码生成器

性能分析插件

开发中会遇到一些慢sql，测试

MP也提供一些性能分析的插件，好像找不到了

条件构造器

wrapper

十分重要

写一些复杂的构造

简单的非空的条件：

@Test
void contextLoads(){
    //查询name不为空，年龄等于12
    QueryWrapper<User> wrapper=new QueryWrapper<>();
    wrapper
    		.isNotNull("name")
    		.isNotNull("email")
    		.ge("age",12);
    		usermapper.selectList(wrapper).forEach(System.out::println);
}

条件有参数查询

@Test
void test2(){
    //查询name不为空，年龄等于12
    QueryWrapper<User> wrapper=new QueryWrapper<>();
    wrapper
    		.eq("name","郝泾钊")；
        //查询一个selectOne 别的用List map
    		usermapper.selectOne(wrapper);
}

范围：

@Test
void test3(){
    //年龄在20-30之间
    QueryWrapper<User> wrapper=new QueryWrapper<>();
    wrapper
    		.between("age",20,30)；
        //查询一个selectOne 别的用List map
    		usermapper.selectCount(wrapper);//数量数目
}

模糊查询

@Test
void test4(){
    //年龄在20-30之间
    QueryWrapper<User> wrapper=new QueryWrapper<>();
    wrapper
        .notLike("name","0")
        .likeRight("email","t");//右边
    List<Map<String,Object>> maps = userMapper.selectMaps(wrapper);
    maps.forEach(System.out::print)
        //查询一个selectOne 别的用List map
    		usermapper.selectCount(wrapper);//数量数目
}

嵌套sql

@Test
void test5(){
    //年龄在20-30之间
    QueryWrapper<User> wrapper=new QueryWrapper<>();
    //id在子查询中查出来
    wrapper.inSql("id","select id from user where id<3");
    List<Object> objects = userMapper.selectPbjects(wrapper);
    maps.forEach(System.out::print)
}

排序：

@Test
void test5(){
    //年龄在20-30之间
    QueryWrapper<User> wrapper=new QueryWrapper<>();
    //id在子查询中查出来
    wrapper.orderByDesc("id");
    List<User> objects = userMapper.selectList(wrapper);
    maps.forEach(System.out::print)
}

代码生成器

main.class:

package com;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.DataSourceConfig;
import com.baomidou.mybatisplus.generator.config.GlobalConfig;
import com.baomidou.mybatisplus.generator.config.PackageConfig;
import com.baomidou.mybatisplus.generator.config.StrategyConfig;
import com.baomidou.mybatisplus.generator.config.rules.NamingStrategy;

public class Main {
    public static void main(String[] args) {
        //创建对象
        AutoGenerator autoGenerator = new AutoGenerator();
        //数据源
        DataSourceConfig dataSourceConfig= new DataSourceConfig();
        dataSourceConfig.setDbType(DbType.MYSQL);
        dataSourceConfig.setDriverName("com.mysql.cj.jdbc.Driver");
        dataSourceConfig.setUrl("jdbc:mysql://localhost:3306/text");
        dataSourceConfig.setUsername("root");
        dataSourceConfig.setPassword("123456");
        autoGenerator.setDataSource(dataSourceConfig);
        //全局配置
        GlobalConfig globalConfig=new GlobalConfig();
        globalConfig.setOutputDir(System.getProperty("user.dir")+"/src/main/java");
        globalConfig.setAuthor("郝泾钊");
        globalConfig.setOpen(false);
        //去掉Service
        globalConfig.setServiceName("%sService");
        autoGenerator.setGlobalConfig(globalConfig);
        //包配置
        PackageConfig packageConfig =new PackageConfig();
        packageConfig.setParent("com.southwind");
        packageConfig.setEntity("entity");
        packageConfig.setMapper("mapper");
        packageConfig.setService("service");
        packageConfig.setServiceImpl("service.impl");
        packageConfig.setController("controller");
        //策略配置
        StrategyConfig strategyConfig =new StrategyConfig();
        strategyConfig.setInclude("people");
        strategyConfig.setNaming(NamingStrategy.underline_to_camel);
        strategyConfig.setColumnNaming(NamingStrategy.underline_to_camel);
        strategyConfig.setEntityLombokModel(true);
        autoGenerator.setStrategy(strategyConfig);
        //启动
        autoGenerator.execute();

    }
}