<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
</dependency>

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.GeneratedValue;

@Entity
@Table(name = "dept")
public class Dept {
	@Id
	@Column(name = "id")
	@GeneratedValue(strategy = GenerationType.AUTO)
	private Long id;
	
	@Column(name = "code")
	private String code;
	
	@Column(name = "name")
	private String name;
}

import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;

@TableName(value = "dept")
public class Dept {
    @TableId(value = "id", type = IdType.AUTO)
    private Long id;

    @TableField(value = "code")
    private String code;

    @TableField(value = "name")
    private String name;
}

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface DeptRepository extends JpaRepository<Dept, Long> {
}

import org.apache.ibatis.annotations.Mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;

@Mapper
public interface DeptMapper extends BaseMapper<Dept> {
}

Dept dept = new Dept();
dept.setCode("100");
dept.setName("Dept1");

// select * from dept where code = '100' and name = 'Dept1';
List<Dept> deptList = deptRepository.findAll(Example.of(dept)); 

Dept dept = new Dept();
dept.setCode("100");
dept.setName("Dept1");

// select * from dept where code like '100%' and name like '%Dept1%';
List<Dept> deptList = deptRepository.findAll(Example.of(dept, ExampleMatcher.matching()
                .withMatcher("code", ExampleMatcher.GenericPropertyMatchers.startsWith())
                .withMatcher("name", ExampleMatcher.GenericPropertyMatchers.contains()))); 

import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.JpaSpecificationExecutor;
import org.springframework.stereotype.Repository;

@Repository
public interface DeptRepository extends JpaRepository<Dept, Long>, JpaSpecificationExecutor<Dept>  {
}

Dept dept = new Dept();
dept.setCode("100");
dept.setName("Dept1");

// select * from dept where code like '100%' and name like '%Dept1%';
Specification<Dept> spec = new Specification<Dept>() {
   @Override
   public Predicate toPredicate(Root<Dept> root, CriteriaQuery<?> query, CriteriaBuilder cb) {
       List<Predicate> predicates = new ArrayList<>();
       predicates.add(cb.like(root.get("code"), dept.getCode() + "%"));
       predicates.add(cb.like(root.get("code"), '%' + dept.getCode() + "%"));
       return query.where(predicates.toArray(new Predicate[predicates.size()])).getRestriction();
    }
};
List<Dept> deptList = deptRepository.findAll(Example.of(dept)); 

Dept dept = new Dept();
dept.setCode("100");
dept.setName("Dept1");

// select * from dept where code = '100' and name = 'Dept';
Wrapper<Dept> wrapper = Wrappers.lambdaQueryWrapper(detp);
List<Dept> deptList = deptRepository.selectList(wrapper); 

Dept dept = new Dept();
dept.setCode("100");
dept.setName("Dept1");

// select * from dept where code like '100%' and name like '%Dept1%';
Wrapper<Dept> wrapper = Wrappers.<Dept>lambdaQueryWrapper()
                        .likeRight(Dept::getCode, dept.getCode)
                        .like(Dept::getName, dept.getName);
List<Dept> deptList = deptRepository.selectList(wrapper); 

@Repository
public interface DeptRepository extends JpaRepository<Dept, Long> {
    
    // 調(diào)用此方法時，會自動生成 where code = ? 的條件
	Dept getByCode(String code);
}

import org.apache.ibatis.annotations.Mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;

@Mapper
public interface DeptMapper extends BaseMapper<Dept> {
    default Dept getByCode(String code) {
		return selectOne(Wrappers.<Dept>lambdaWrapper().eq(Dept::getCode, code));
	}
}

import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;

@Repository
public interface DeptRepository extends JpaRepository<Dept, Long> {
    @Query(value = "select d from Dept d where d.code = ?1")
	Dept getByCode(String code);

    @Modifying
    @Query(value = "delete from Dept d where d.code = :code")
    int deleteByCode(@Param("code") String code);
}

import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;

@Repository
public interface DeptRepository extends JpaRepository<Dept, Long> {
    @Query(value = "SELECT * FROM dept WHERE name = ?1", countQuery = "SELECT count(*) FROM dept WHERE name = ?1", nativeQuery = true)
    Page<Dept> findByName(@Param("name") String name, Pageable pageable);
}

<named-query name="Dept.getByCode">
  <query> select d from Dept d where d.code = ?1</query>
</named-query>
<named-native-query name="Dept.deleteByCode">
  <query> DELETE FROM dept WHERE code = ?1</query>
</named-native-query>

import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.metadata.IPage;

@Mapper
public interface DeptMapper extends BaseMapper<Dept> {
    @Select(value = "SELECT * FROM dept WHERE code = #[code]")
	Dept getByCode(@Param("code") String code);

    @Delete("DELETE FROM dept WHERE code = #[code]")
    int deleteByCode(@Param("code") String code);
    
    @Select(value = "SELECT * FROM dept WHERE name = #{name}")
    IPage<Dept> findByName(@Param("name") String name, IPage<Dept> page);
}

<mapper namespace="DeptMapper">
	<select id = "getByCode", resultType = "Dept">
		SELECT * FROM dept WHERE code = #[code]
	</select>
	<delete id = "deleteByCode">
		DELETE FROM dept WHERE code = #[code]
	</select>
	<select id = "findByName">
		SELECT * FROM dept WHERE name = #{name}
	</select>
</mapper>