Java开发之Mybatis框架

mybasits配置文件书写
1.configer文件配置

PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">;





















2.mapper文件配置
(1)resultType是返回值类型
（2）pramatetertype是传入的参数

PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">;





SELECT * FROM table4012
limit #{offset},#{pagesize}



insert into table4012(id,username,number,mybasits,android,javaee) values (#{id},#{username},#{number},#{mybasits},#{android},#{javaee})


delete from table4012 where id=#{**}


update table4012 set username=#{username},number =#{number},mybasits=#{mybasits},android=#{android},javaee=#{javaee} where id=#{id}


SELECT count () from table4012


SELECT * from table4012


3.util类配置
package com.SelfStudy.util;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import java.io.InputStream;
public class Util {
private static SqlSessionFactory build;//定义一个对象
static {
String s="mybatis.config.xml";//加载config文件
InputStream inputStream=null;//输入输出流
try {
inputStream= Resources.getResourceAsStream(s);
build=new SqlSessionFactoryBuilder().build(inputStream);
}
catch (Exception e){
e.printStackTrace();
}
finally {
try {
if ( inputStream !=null){
inputStream.close();
}
}catch (Exception e){
e.printStackTrace();
}
}
}
public static SqlSession getSession(){
return build.openSession();
}
}
4.log4j.properties文件配置
log4j.appender.console =org.apache.log4j.ConsoleAppender
log4j.appender.console.Target =System.out
log4j.appender.console.layout =org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern =[%-5p][%d{yyyy-MM-dd HH:mm:ss}] %c %L %m%n

\u914D\u7F6E\u6839

log4j.rootLogger =debug,console
##log4j.logger.com.mapper.StudentMapper=debug,console
四.动态sql
1.if set标签的使用
Select from table
if(test="name!=null and name!=''"){
#{id}
}
如果是数据库添加语句在每一句后面添加，
if(test="name!=null and name!=''"){
#{id}，
}
2.where标签的使用
Select from table

if(test="name!=null and name!=''"){
name=#{name}
}
如果是数据库添加语句在每一句后面添加，
if(test="id!=null and id!=''"){
id=#{id}
}

3.choose when标签的使用



and name=#{name}

4. set标签的使用
   uddate Table
   set id=#{id}
   
   
   
5. trim标签的使用
   
   update Teacher
   
   name=#{name},age=#{age},
   
   where id=#{id}
   
   prefix=“在前面进行添加”
   prefixOverrides=“在前面进行去掉”
   suffix=“在后面进行添加”
   suffixOverrides=“在后面进行去掉”
   重点:执行的顺序 先去除再添加
6. bind标签
   
   slct * from tabl wr nam lik #{nam}
7. foreach（集合查询，添加）
   
   insert into table () valuse
   
   #{},
   
   
   collection:传入的参数类型
   open:打开方式
   close：关闭方式
   item:item
8. selectkey 的使用（查询上一条记录的一个属性）
   
   insert table valuse()
   
   select last_insert_name()
   
   keypropert是查询的属性的名称
   resulttype是XM代理申请www.fx61.com/brokerlist/xm.html返回值类型,是查询结果的返回值类型
   order是执行顺序
   keycolum:数据库中对应的属性
   多种查询方法的使用
   1.模糊查询
   select from table where name=#{name}
   [1]在查询的时候改正
   SelectAll("%ko%");
   [2]在sql语句中改正
   使用concat函数
   select from table where
   id=concat('%',#{id},'%')
9. 多表联合查询
   (1) mapper文件的配置类
   
   //封装连接类的属性，主要是主类属性
   
   
   
   
   //用association封装子类所有的属性
   
   
   
   
   
   
   SELECT * FROM people ,peopledatil//联合查询，动态sql
   
   people.id=peopledatil.id
   
   
   (2) test测试类br/>@org.junit.Test
   public void TestTogether(){
   SqlSession session=Util.getSession();
   PeopleMapperDao peopleMapperDao=session.getMapper(PeopleMapperDao.class);
   peopleMapperDao.SelectTogether();
   List list=null;
   list=peopleMapperDao.SelectTogether();
   System.out.println(list);
   }
   3.一对一联合查询
   配置类文件
   package com.pojo;
   public class Student {
   private String name;
   private Integer id;
   private Integer tid;//和老师中的id对因
   private String address;
   private String city;
   //一个学生对应一个老师
   private Teacher teacher;//在学生中查询老师
   public String getName() {
   return name;
   }
   public void setName(String name) {
   this.name = name;
   }
   public Integer getId() {
   return id;
   }
   public void setId(Integer id) {
   this.id = id;
   }
   public Integer getTid() {
   return tid;
   }
   public void setTid(Integer tid) {
   this.tid = tid;
   }
   public String getAddress() {
   return address;
   }
   public void setAddress(String address) {
   this.address = address;
   }
   public String getCity() {
   return city;
   }
   public void setCity(String city) {
   this.city = city;
   }
   public Teacher getTeacher() {
   return teacher;
   }
   public void setTeacher(Teacher teacher) {
   this.teacher = teacher;
   }
   public Student(String name, Integer id, Integer tid, String address, String city, Teacher teacher) {
   this.name = name;
   this.id = id;
   this.tid = tid;
   this.address = address;
   this.city = city;
   this.teacher = teacher;
   }
   public Student() { }br/>@Override
   public String toString() {
   return "Student{" +
   "name='" + name + '\'' +
   ", id=" + id +
   ", tid=" + tid +
   ", address='" + address + '\'' +
   ", city='" + city + '\'' +
   ", teacher=" + teacher +
   '}';
   }
   }
   接口配置
   package com.service;
   import com.pojo.Student;
   import java.util.List;
   public interface StudentDao {
   public List Selectall();
   public List SelectByid(Integer id);
   //查询所有学生
   public List SelectAllStudent();
   public List selct01();
   }
   mapper文件配置
   
   PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
   "http://mybatis.org/dtd/mybatis-3-mapper.dtd">;
   
   
   
   
   
   
   
   
   
   
   
   SELECT s.name, s.id ,s.tid ,s.address , s.city ,t.name , school ,age , sex,t.id
   FROM student s LEFT JOIN teacher t on
   s.tid=t.id
   
   4.多对一联合查询
   
   
   
   
   
   
   
   
   
   
   
   
   
   
10. 多对多的联合查询
    实体类的配置
    package com.pojo;
    import java.util.Date;
    import java.util.List;
    public class Writer {
    private String name;
    private Integer id;
    private Integer age;
    private String sex;
    private String book;
    private Date birthday;
    //查询作者里面包含作品
    private List works;
    public List getWorks() {
    return works;
    }
    public void setWorks(List works) {
    this.works = works;
    }
    public Writer(List works) {
    this.works = works;br/>}
    @Override
    public String toString() {
    return "Writer{" +
    "name='" + name + '\'' +
    ", id=" + id +
    ", age=" + age +
    ", sex='" + sex + '\'' +
    ", book='" + book + '\'' +
    ", birthday=" + birthday +
    ", works=" + works +
    '}';
    }
    public String getName() {
    return name;
    }
    public void setName(String name) {
    this.name = name;
    }
    public Integer getId() {
    return id;
    }
    public void setId(Integer id) {
    this.id = id;
    }
    public Integer getAge() {
    return age;
    }
    public void setAge(Integer age) {
    this.age = age;
    }
    public String getSex() {
    return sex;
    }
    public void setSex(String sex) {
    this.sex = sex;
    }
    public String getBook() {
    return book;
    }
    public void setBook(String book) {
    this.book = book;
    }
    public Date getBirthday() {
    return birthday;
    }
    public void setBirthday(Date birthday) {
    this.birthday = birthday;
    }
    public Writer(String name, Integer id, Integer age, String sex, String book, Date birthday) {
    this.name = name;
    this.id = id;
    this.age = age;
    this.sex = sex;
    this.book = book;
    this.birthday = birthday;
    }
    public Writer() { }
    }
    mapper文件配置
    
    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">;
    
    
    
    select from writer w
    
    
    select from writer w
    
    id=#{id}
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    SELECT w.age,w.birthday,w.book,w.id,w.name,w.sex ,o.book_id,o.book_press,o.press_date,o.book_name
    FROM writer w LEFT JOIN information i ON w.id=i.writer_idLEFT JOIN works o ON o.book_id=i.works_idbr/>
    
    注解方式配置
    @Results(value={
    @Result(id=true,column="",property=""),br/>@Result(column="",property=""),
    @Result(column="",property=""),br/>@Result(column="",property=""),
    @Result(column="",property=""),br/>@Result(column="",property=""),
    @Result(column="",property=""), @Result(column="tid",property="works",many=@Many(Select="com.service.iuserdao.workByid") ),br/>})
    @Select(".......")
    java导入Excel表格
11. 导入包
    
    org.apache.poi
    poi
    3.17
    
    
    
    commons-io
    commons-io
    2.4
    
    //导入依赖
    2.构建方法
    public class ImportExcel {
    //导入excel文件的方法
    public void ReadExcel(File file){
    List list=new ArrayList<>();
    //1.传入需要导入的Excel文件的路径
    try{
    //2.读取文件的内容
    HSSFWorkbook workbook=new HSSFWorkbook(FileUtils.openInputStream(file));
    //3.读取文件的sheet页,sheet就是Excel中的每一张表，也就是workboo的sheet页
    HSSFSheet sheet=workbook.getSheetAt(0);
    //4.开始读取表的内容
    int startline=0;//起始行的行数，也就是从0 到最后一行
    int endline=sheet.getLastRowNum()+1;//最后一行d的下表
    //遍历每一行
    Map> map=new HashMap<>();
    //第一行，第一列，值
    //遍历行
    for (int a=1;aHSSFRow hssfRow=sheet.getRow(a);
    //遍历列
    //写一个集合存储列和值
    Map result=new HashMap<>();
    int endcell=hssfRow.getLastCellNum();
    for (int j=0;jresult.put(j, hssfRow.getCell(j));//用行数去获取列
    }
    map.put(a, result);
    }
    List list1=new ArrayList<>();
    for (Integer xxx:map.keySet()){
    System.out.print(map.get(xxx).get(0));
    System.out.print(map.get(xxx).get(1));
    System.out.print(map.get(xxx).get(2));
    System.out.print(map.get(xxx).get(3));
    People people=new People();
    people.setName(String.valueOf(map.get(xxx).get(0)));
    String java=String.valueOf(map.get(xxx).get(1));
    Integer java1=Integer.parseInt(java.substring(0, java.indexOf(".")));
    people.setJava(java1);
    String mybas=String.valueOf(map.get(xxx).get(2));
    Integer mybas1=Integer.parseInt(mybas.substring(0, mybas.indexOf(".")));
    people.setMybas(mybas1);
    String androi=String.valueOf(map.get(xxx).get(3));
    Integer androi1=Integer.parseInt(androi.substring(0, androi.indexOf(".")));
    people.setAndroi(androi1);
    list1.add(people);
    }
    SqlSession session= Util.getSession();
    PeopleMapperDao peopleMapperDao=session.getMapper(PeopleMapperDao.class);
    peopleMapperDao.ExcelInsert(list1);
    session.commit();
    }
    catch (Exception e){
    e.printStackTrace();
    }
    }
    }
12. 调用方法br/>@org.junit.Test
    public void TestExcel(){
    ImportExcel aaa=new ImportExcel();
    File file=new File("C:/Users/lenovo/Desktop/study/ssm笔记/test4012.xls");
    aaa.ReadExcel(file);
    }