java 中MyBatis注解映射的实例详解

java  中mybatis注解映射的实例详解

１.普通映射 

@select("select * from mybatis_student where id=#{id}") 
public student getstudent(int id); 
@insert("insert into mybatis_student (name, age, remark, pic,grade_id,address_id) values (#{name},#{age},#{remark}, #{pic},#{grade.id},#{address.id})") 
public int insert(student student); 
@update("update mybatis_student set name=#{name},age=#{age} where id=#{id}") 
public int update(student student); 
@delete("delete from mybatis_student where id=#{id}") 
public int delete(int id); 

 ２.结果集映射

@select("select * from mybatis_student") 
@results({ 
  @result(id=true,property="id",column="id"), 
  @result(property="name",column="name"), 
  @result(property="age",column="age") 
}) 
public list<student> getallstudents(); 

 ３.关系映射

     1),一对一

@select("select * from mybatis_student") 
@results({ 
  @result(id=true,property="id",column="id"), 
  @result(property="name",column="name"), 
  @result(property="age",column="age"), 
    @result(property="address",column="address_id",one=@one(select="com.skymr.mybatis.mappers.addressmapper.getaddress")) 
}) 
public list<student> getallstudents(); 

    2)一对多

package com.skymr.mybatis.mappers; 
 
import org.apache.ibatis.annotations.many; 
import org.apache.ibatis.annotations.result; 
import org.apache.ibatis.annotations.results; 
import org.apache.ibatis.annotations.select; 
 
import com.skymr.mybatis.model.grade; 
 
public interface grade2mapper { 
 
  @select("select * from mybatis_grade where id=#{id}") 
  @results({ 
    @result(id=true,column="id",property="id"), 
    @result(column="grade_name",property="gradename"), 
    @result(property="students",column="id",many=@many(select="com.skymr.mybatis.mappers.student2mapper.getstudentsbygradeid")) 
  }) 
  public grade getgrade(int id); 
} 

  java代码 

package com.skymr.mybatis.mappers; 
 
import java.util.list; 
 
import org.apache.ibatis.annotations.delete; 
import org.apache.ibatis.annotations.insert; 
import org.apache.ibatis.annotations.one; 
import org.apache.ibatis.annotations.result; 
import org.apache.ibatis.annotations.results; 
import org.apache.ibatis.annotations.select; 
import org.apache.ibatis.annotations.update; 
 
import com.skymr.mybatis.model.student; 
 
public interface student2mapper { 
 
  @select("select * from mybatis_student where id=#{id}") 
  public student getstudent(int id); 
  @insert("insert into mybatis_student (name, age, remark, pic,grade_id,address_id) values (#{name},#{age},#{remark}, #{pic},#{grade.id},#{address.id})") 
  public int insert(student student); 
  @update("update mybatis_student set name=#{name},age=#{age} where id=#{id}") 
  public int update(student student); 
  @delete("delete from mybatis_student where id=#{id}") 
  public int delete(int id); 
   
  @select("select * from mybatis_student") 
  @results({ 
    @result(id=true,property="id",column="id"), 
    @result(property="name",column="name"), 
    @result(property="age",column="age"), 
    @result(property="address",column="address_id",one=@one(select="com.skymr.mybatis.mappers.addressmapper.getaddress")) 
  }) 
  public list<student> getallstudents(); 
  @select("select * from mybatis_student where grade_id=#{gradeid}") 
    @results({ 
    @result(id=true,property="id",column="id"), 
    @result(property="name",column="name"), 
    @result(property="age",column="age"), 
    @result(property="address",column="address_id",one=@one(select="com.skymr.mybatis.mappers.addressmapper.getaddress")) 
  }) 
  public list<student> getstudentsbygradeid(int gradeid); 
} 

 ４.动态sql注解映射

provider类

package com.skymr.mybatis.mappers.provider; 
 
import java.util.map; 
 
import org.apache.ibatis.jdbc.sql; 
 
import com.skymr.mybatis.model.student; 
 
public class studentdynasqlprovider { 
 
  public string insertstudent(final student student){ 
    return new sql(){ 
      { 
        insert_into("mybatis_student"); 
        if(student.getname() != null){ 
          values("name","#{name}"); 
        } 
        if(student.getage() > 0){ 
          values("age","#{age}"); 
        } 
      } 
    }.tostring(); 
  } 
   
  public string updatestudent(final student student){ 
    return new sql(){ 
      { 
        update("mybatis_student"); 
        if(student.getname() != null){ 
          set("name=#{name}"); 
        } 
        if(student.getage() > 0){ 
          set("age=#{age}"); 
        } 
        where("id=#{id}"); 
      } 
    }.tostring(); 
  } 
   
  public string getstudent(final map<string,object> map){ 
    return new sql(){ 
      { 
        select("*"); 
        from("mybatis_student"); 
        if(map.containskey("name")){ 
          where("name like #{name}"); 
        } 
        if(map.containskey("age")){ 
          where("age=#{age}"); 
        } 
      } 
    }.tostring(); 
  } 
   
  public string deletestudent(){ 
    return new sql(){ 
      { 
        delete_from("mybatis_student"); 
        where("id=#{id}"); 
      } 
    }.tostring(); 
  } 
} 

 mapper接口

@selectprovider(type=studentdynasqlprovider.class,method="getstudent") 
public list<student> getstudents(map<string,object> map); 
 

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