MYBatis 动态SQL

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);
}

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);

link: http://blog.csdn.net/naruto_mr/article/details/48207437