根據前兩篇博文，相信大夥看完之後，應該對Spring Data JPA有了一個感性的認識。接下來，我們來看看Spring Data JPA的查詢方法
UserInfo 實體：前文提到過，用myeclipse的生成JPA實體逆向生成：
package com.example.entity;
import java.sql.Timestamp;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.UniqueConstraint;
/**
* UserInfo entity. @author MyEclipse Persistence Tools
*/
@Entity
@Table(name="user_info"
,catalog="rbac"
, uniqueConstraints = @UniqueConstraint(columnNames="username")
)
public class UserInfo implements java.io.Serializable {
// Fields
private String id;
private String username;
private String password;
private String sex;
private Timestamp birthday;
private String email;
private String contact;
private String onlineState;
private Timestamp lastLoginTime;
private Timestamp lastLogoutTime;
private String lastLoginIp;
private String userState;
private Integer listOrder;
private String createUser;
private Timestamp createDatetime;
private String modifyUser;
private Timestamp modifyDatetime;
private String deleteFlag;
// Constructors
/** default constructor */
public UserInfo() {
}
/** minimal constructor */
public UserInfo(String id, String username, String password) {
this.id = id;
this.username = username;
this.password = password;
}
/** full constructor */
public UserInfo(String id, String username, String password, String sex, Timestamp birthday, String email, String contact, String onlineState, Timestamp lastLoginTime, Timestamp lastLogoutTime, String lastLoginIp, String userState, Integer listOrder, String createUser, Timestamp createDatetime, String modifyUser, Timestamp modifyDatetime, String deleteFlag) {
this.id = id;
this.username = username;
this.password = password;
this.sex = sex;
this.birthday = birthday;
this.email = email;
this.contact = contact;
this.onlineState = onlineState;
this.lastLoginTime = lastLoginTime;
this.lastLogoutTime = lastLogoutTime;
this.lastLoginIp = lastLoginIp;
this.userState = userState;
this.listOrder = listOrder;
this.createUser = createUser;
this.createDatetime = createDatetime;
this.modifyUser = modifyUser;
this.modifyDatetime = modifyDatetime;
this.deleteFlag = deleteFlag;
}
// Property accessors
@Id
@Column(name="id", unique=true, nullable=false, length=50)
public String getId() {
return this.id;
}
public void setId(String id) {
this.id = id;
}
@Column(name="username", unique=true, nullable=false, length=50)
public String getUsername() {
return this.username;
}
public void setUsername(String username) {
this.username = username;
}
@Column(name="password", nullable=false, length=50)
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
@Column(name="sex", length=1)
public String getSex() {
return this.sex;
}
public void setSex(String sex) {
this.sex = sex;
}
@Column(name="birthday", length=0)
public Timestamp getBirthday() {
return this.birthday;
}
public void setBirthday(Timestamp birthday) {
this.birthday = birthday;
}
@Column(name="email", length=50)
public String getEmail() {
return this.email;
}
public void setEmail(String email) {
this.email = email;
}
@Column(name="contact", length=50)
public String getContact() {
return this.contact;
}
public void setContact(String contact) {
this.contact = contact;
}
@Column(name="online_state", length=1)
public String getOnlineState() {
return this.onlineState;
}
public void setOnlineState(String onlineState) {
this.onlineState = onlineState;
}
@Column(name="last_login_time", length=0)
public Timestamp getLastLoginTime() {
return this.lastLoginTime;
}
public void setLastLoginTime(Timestamp lastLoginTime) {
this.lastLoginTime = lastLoginTime;
}
@Column(name="last_logout_time", length=0)
public Timestamp getLastLogoutTime() {
return this.lastLogoutTime;
}
public void setLastLogoutTime(Timestamp lastLogoutTime) {
this.lastLogoutTime = lastLogoutTime;
}
@Column(name="last_login_ip", length=50)
public String getLastLoginIp() {
return this.lastLoginIp;
}
public void setLastLoginIp(String lastLoginIp) {
this.lastLoginIp = lastLoginIp;
}
@Column(name="user_state", length=50)
public String getUserState() {
return this.userState;
}
public void setUserState(String userState) {
this.userState = userState;
}
@Column(name="list_order")
public Integer getListOrder() {
return this.listOrder;
}
public void setListOrder(Integer listOrder) {
this.listOrder = listOrder;
}
@Column(name="create_user", length=20)
public String getCreateUser() {
return this.createUser;
}
public void setCreateUser(String createUser) {
this.createUser = createUser;
}
@Column(name="create_datetime", length=0)
public Timestamp getCreateDatetime() {
return this.createDatetime;
}
public void setCreateDatetime(Timestamp createDatetime) {
this.createDatetime = createDatetime;
}
@Column(name="modify_user", length=20)
public String getModifyUser() {
return this.modifyUser;
}
public void setModifyUser(String modifyUser) {
this.modifyUser = modifyUser;
}
@Column(name="modify_datetime", length=0)
public Timestamp getModifyDatetime() {
return this.modifyDatetime;
}
public void setModifyDatetime(Timestamp modifyDatetime) {
this.modifyDatetime = modifyDatetime;
}
@Column(name="delete_flag", length=1)
public String getDeleteFlag() {
return this.deleteFlag;
}
public void setDeleteFlag(String deleteFlag) {
this.deleteFlag = deleteFlag;
}
}下面來看看完整的UserInfoService.java
package com.example.service.impl;
import java.util.List;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Slice;
import org.springframework.data.domain.Sort;
import com.example.common.BaseService;
import com.example.entity.UserInfo;
public interface UserInfoService extends BaseService<UserInfo, String>{
//根據username查詢用戶信息
public List<UserInfo> findByUsername(String username);
//根據用戶名和密碼查詢用戶信息
public UserInfo findByUsernameAndPassword(String name, String password);
//原生SQL查詢，且綁定參數的方式
//@Query(value = "SELECT * FROM USERS WHERE EMAIL_ADDRESS = ?1", nativeQuery = true)
//@Query("select u from UserInfo u where u.email = ?1")
List<UserInfo> findByEmail(String email);
//參數查詢
// @Query("select u from User u where u.firstname = :firstname or u.lastname = :lastname")
// UserInfo findByLastnameOrFirstname(@Param("lastname") String lastname,
// @Param("firstname") String firstname);
// Enables the distinct flag for the query
List<UserInfo> findDistinctUserInfoByUsernameOrEmail(String name,
String email);
List<UserInfo> findUserInfoDistinctByUsernameOrEmail(String name,
String email);
List<UserInfo> findTop10ByUsername(String Username, Pageable pageable);
// Enabling ignoring case for an individual property
List<UserInfo> findByUsernameIgnoreCase(String name);
// Enabling ignoring case for all suitable properties
List<UserInfo> findByUsernameAndEmailAllIgnoreCase(String name,
String email);
// Enabling static ORDER BY for a query
List<UserInfo> findByUsernameOrderByUsernameAsc(String name);
List<UserInfo> findByUsernameOrderByUsernameDesc(String name);
//Between, LessThan, GreaterThan, Like
UserInfo findFirstByOrderByUsernameAsc();
//UserInfo findTopByOrderByAgeDesc();
//Page<UserInfo> queryFirst10ByUsername(String Username, Pageable pageable);
Slice<UserInfo> findTop3ByUsername(String Username, Pageable pageable);
List<UserInfo> findFirst10ByUsername(String Username, Sort sort);
}上面的命名具有一定的規範，總結下來就是：
find+全局修飾+By+實體屬性名+Keyword+ .(其它實體屬性)+OrderBy+
排序實體屬性+排序方式
例如：
findDistnctByUsernameIgnoreCaseAndPasswordOrderByAgeDsc(String
firstName,String lastName){.}
其中：Distnct是全局修飾（非必須），Username和Password是實體的屬性名，
And、IgnoreCase都是關鍵字，Age是排序屬性，Desc是排序方式
常用詞如下：
全局修飾：Distnct，Top，First
keyword：如圖1,2所示
IgnoreCase，Betwen，Equals，LesThan，GreaterThan，After，Before.
排序方式：Asc，Desc
連接詞：And，Or關鍵字列表：
圖1. 查詢的關鍵字
上面的查詢方式，詳細大夥都已經非常的清楚了，畢竟上述查詢有些也不能滿足我們的需求，因此下一篇文章將講述如何進行自定義的查詢方式。