本節主要介紹Repository Bean中方法定義規範。

1、方法不是隨便宣告，需要符合一定的規範。

2、按照Spring Data的規範，查詢方法以find|read|get開頭，涉及條件查詢時，條件的屬性用條件關鍵字連線，要注意的是：條件屬性需要首字母大寫。

3、Spring Data支援的關鍵字如下：

4、支援屬性的級聯查詢，若當前類有符合條件的屬性，則優先使用，而不使用級聯屬性。若想使用級聯屬性，則屬性之間用"_"連線。

package com.ntjr.springdata;

import java.util.Date;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

@Table(name = "JPA_PERSONS")
@Entity
public class Person {

  private Integer id;
  private String lastName;
  private String email;
  private Date birth;
  private Address address;
  private Integer addressId;

  @GeneratedValue
  @Id
  public Integer getId() {
    return id;
  }

  public void setId(Integer id) {
    this.id = id;
  }

  public String getLastName() {
    return lastName;
  }

  @Column(name = "LAST_NAME")
  public void setLastName(String lastName) {
    this.lastName = lastName;
  }

  public String getEmail() {
    return email;
  }

  public void setEmail(String email) {
    this.email = email;
  }

  public Date getBirth() {
    return birth;
  }

  public void setBirth(Date birth) {
    this.birth = birth;
  }

  @JoinColumn(name = "ADDRESS_ID")
  @ManyToOne(cascade = { CascadeType.ALL },targetEntity = Address.class)
  public Address getAddress() {
    return address;
  }

  public void setAddress(Address address) {
    this.address = address;
  }


  public Integer getAddressId() {
    return addressId;
  }

  public void setAddressId(Integer addressId) {
    this.addressId = addressId;
  }

  @Override
  public String toString() {
    return "Person [id=" + id + ",lastName=" + lastName + ",email=" + email + ",birth=" + birth + "]";
  }

}

package com.ntjr.springdata;

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

@Table(name="JPA_ADDRESSES")
@Entity
public class Address {

  private Integer id;
  private String province;
  private String city;

  @GeneratedValue
  @Id
  public Integer getId() {
    return id;
  }

  public void setId(Integer id) {
    this.id = id;
  }

  public String getProvince() {
    return province;
  }

  public void setProvince(String province) {
    this.province = province;
  }

  public String getCity() {
    return city;
  }

  public void setCity(String city) {
    this.city = city;
  }

}

package com.ntjr.springdata;

import java.util.Date;
import java.util.List;

import org.springframework.data.repository.RepositoryDefinition;

/**
 *
 * 1、實現Repository介面 2、通過註解的方式@RepositoryDefinition將一個bean定義為Repository介面
 */
@RepositoryDefinition(idClass = Integer.class,domainClass = Person.class)
public interface PersonRepsitory {
  // 根據lastName獲取對應的person
  Person getByLastName(String lastName);

  // WHERE lastName like ?% AND id<?
  List<Person> findByLastNameStartingWithAndIdLessThan(String lastName,Integer id);

  // WHERE lastName Like %? And Id <?
  List<Person> findByLastNameEndingWithAndIdLessThan(String lastName,Integer id);

  // WHERE email IN(?,?,?) Or birth <?
  List<Person> findByEmailInOrBirthLessThan(List<String> emails,Date birth);

  // WHERE a.id >?
  /**
   * AddressId 優先查詢Person類中的AddressId屬性，如果Person類中沒有，就查詢Address類中的Id屬性
   * 這樣容易出現問題，建議級聯查詢中，屬性之間使用"_"連線
   *
   */
  List<Person> findByAddressIdGreaterThan(Integer id);

  // 這樣就很明確是進行級聯查詢，Address類中的ID屬性
  List<Person> findByAddress_IdGreaterThan(Integer id);
}

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。