-----业务场景中经常涉及到联查，jpa的hql语法提供了内连接的查询方式（不支持复杂hql，比如left join ，right join）. 上代码了
1.我们要联查房屋和房屋用户中间表，通过房屋id关联 homeInfo是房屋表，homeUser是房屋用户中间表.
homeInfo
1 package management.entity.carandhome;
2
3 import java.io.Serializable;
4 import java.math.BigDecimal;
5 import java.util.ArrayList;
6 import java.util.Date;
7 import java.util.HashSet;
8 import java.util.List;
9 import java.util.Set;
10
11 import javax.persistence.Entity;
12 import javax.persistence.FetchType;
13 import javax.persistence.GeneratedValue;
14 import javax.persistence.Id;
15 import javax.persistence.JoinColumn;
16 import javax.persistence.JoinTable;
17 import javax.persistence.ManyToMany;
18 import javax.persistence.OneToMany;
19 import javax.persistence.OneToOne;
20 import javax.persistence.Table;
21
22 import org.hibernate.annotations.NotFound;
23 import org.hibernate.annotations.NotFoundAction;
24
25 import com.alibaba.fastjson.annotation.JSONField;
26 import management.entity.paymentfee.LifeFee;
27 import management.entity.paymentfee.ManageFee;
28
29 @Entity
30 @Table(name = "t_ss_w_home")
31 // 房屋信息表
32 public class HomeInfo implements Serializable {
33
34 /**
35 *
36 */
37 private static final long serialVersionUID = 1L;
38
39 public HomeInfo() {
40 super();
41 // TODO Auto-generated constructor stub
42 }
43
44
45 @Id
46 @GeneratedValue
47 // 房屋ID
48 private Long homeID;
49
50 // 用户id，这个是标识房主的用户id,关联表查询出来的房主不靠谱
51 private Long userID;
52
53 // @NotNull
54 // @Size(min = 3, max = 16)
55 // 房屋面积
56 private BigDecimal grossArea;
57
58 // 实际面积
59 private BigDecimal realArea;
60
61 // 户型
62 private String houseType;
63
64 // 朝向
65 private String orientaion;
66
67 // 入住时间
68 @JSONField(format = "yyyy-MM-dd")
69 private Date chechTime;
70
71 // 楼号
72 private String homeNo;
73
74 // 单元号
75 private String homeUnit;
76
77 // 房间号
78 private String homeRoom;
79
80 // 手机号
81 private String mobileNo;
82
83 // 备注
84 private String homeRemark;
85
86 // 房屋状态
87 private String homeState;
88
89 // 房产性质
90 private String homeNature;
91
92 // 楼层
93 private String homeFloor;
94
95 // 房屋位置
96 private String homeLo;
97
98 public Long getUserID() {
99 return userID;
100 }
101
102 public void setUserID(Long userID) {
103 this.userID = userID;
104 }
105 //
106
107 @OneToMany(fetch = FetchType.EAGER, mappedBy = "homeInfo")
108 @NotFound(action = NotFoundAction.IGNORE)
109 private Set<HomeUser> homeUserList = new HashSet<>();
110
111 @OneToMany(mappedBy = "homeInfo", fetch = FetchType.EAGER)
112 @NotFound(action = NotFoundAction.IGNORE)
113 private Set<ManageFee> manageFeeList = new HashSet<>();
114
115 @OneToMany(mappedBy = "homeInfo", fetch = FetchType.EAGER)
116 @NotFound(action = NotFoundAction.IGNORE)
117 private Set<LifeFee> lifeFeeList = new HashSet<>();
118
119 @NotFound(action = NotFoundAction.IGNORE)
120 @OneToOne(fetch = FetchType.EAGER)
121 @JoinColumn(name = "homeID", referencedColumnName = "homeID", insertable = false, updatable = false)
122 private HouseConfirm houseConfirm;
123
124 public List<HomeUser> getHomeUserList() {
125 return new ArrayList<>(homeUserList);
126 }
127
128 public void setHomeUserList(Set<HomeUser> homeUserList) {
129 this.homeUserList = homeUserList;
130 }
131
132 public Long getHomeID() {
133 return homeID;
134 }
135
136 public void setHomeID(Long homeID) {
137 this.homeID = homeID;
138 }
139
140 public BigDecimal getGrossArea() {
141 return grossArea;
142 }
143
144 public void setGrossArea(BigDecimal grossArea) {
145 this.grossArea = grossArea;
146 }
147
148 public BigDecimal getRealArea() {
149 return realArea;
150 }
151
152 public void setRealArea(BigDecimal realArea) {
153 this.realArea = realArea;
154 }
155
156 public String getHouseType() {
157 return houseType;
158 }
159
160 public void setHouseType(String houseType) {
161 this.houseType = houseType;
162 }
163
164 public String getOrientaion() {
165 return orientaion;
166 }
167
168 public void setOrientaion(String orientaion) {
169 this.orientaion = orientaion;
170 }
171
172 public Date getChechTime() {
173 return chechTime;
174 }
175
176 public void setChechTime(Date chechTime) {
177 this.chechTime = chechTime;
178 }
179
180 public String getMobileNo() {
181 return mobileNo;
182 }
183
184 public void setMobileNo(String mobileNo) {
185 this.mobileNo = mobileNo;
186 }
187
188 public String getHomeRemark() {
189 return homeRemark;
190 }
191
192 public void setHomeRemark(String homeRemark) {
193 this.homeRemark = homeRemark;
194 }
195
196 public String getHomeState() {
197 return homeState;
198 }
199
200 public void setHomeState(String homeState) {
201 this.homeState = homeState;
202 }
203
204 public String getHomeNature() {
205 return homeNature;
206 }
207
208 public void setHomeNature(String homeNature) {
209 this.homeNature = homeNature;
210 }
211
212 public String toString() {
213 return "{homeState:" + this.homeState + "}";
214 }
215
216 public String getHomeLo() {
217 return homeLo;
218 }
219
220 public void setHomeLo(String homeLo) {
221 this.homeLo = homeLo;
222 }
223
224 public List<ManageFee> getManageFeeList() {
225 return new ArrayList<>(manageFeeList);
226 }
227
228 public void setManageFeeList(Set<ManageFee> manageFeeList) {
229 this.manageFeeList = manageFeeList;
230 }
231
232 public List<LifeFee> getLifeFeeList() {
233 return new ArrayList<>(lifeFeeList);
234 }
235
236 public void setLifeFeeList(Set<LifeFee> lifeFeeList) {
237 this.lifeFeeList = lifeFeeList;
238 }
239
240 public String getHomeNo() {
241 return homeNo;
242 }
243
244 public void setHomeNo(String homeNo) {
245 this.homeNo = homeNo;
246 }
247
248 public String getHomeUnit() {
249 return homeUnit;
250 }
251
252 public void setHomeUnit(String homeUnit) {
253 this.homeUnit = homeUnit;
254 }
255
256 public String getHomeRoom() {
257 return homeRoom;
258 }
259
260 public void setHomeRoom(String homeRoom) {
261 this.homeRoom = homeRoom;
262 }
263
264 public String getHomeFloor() {
265 return homeFloor;
266 }
267
268 public void setHomeFloor(String homeFloor) {
269 this.homeFloor = homeFloor;
270 }
271
272 public HouseConfirm getHouseConfirm() {
273 return houseConfirm;
274 }
275
276 public void setHouseConfirm(HouseConfirm houseConfirm) {
277 this.houseConfirm = houseConfirm;
278 }
279
280 }
homeUser
1 package management.entity.carandhome;
2
3 import com.alibaba.fastjson.annotation.JSONField;
4 import com.fasterxml.jackson.annotation.JsonIgnore;
5 import org.hibernate.annotations.NotFound;
6 import org.hibernate.annotations.NotFoundAction;
7
8 import javax.persistence.*;
9 import java.io.Serializable;
10
11 @Entity
12 @Table(name = "t_ss_w_home_user")
13 public class HomeUser implements Serializable {
14
15 /**
16 *
17 */
18 private static final long serialVersionUID = 1L;
19
20
21 @Id
22 @GeneratedValue
23 private Long homeUserID;
24
25 private Long userID;
26
27 private Long homeID;
28
29 @JSONField
30 @JsonIgnore
31 @ManyToOne
32 @JoinColumn(name = "homeID", insertable = false, updatable = false)
33 @NotFound(action = NotFoundAction.IGNORE)
34 private HomeInfo homeInfo;
35
36 public HomeUser() {
37 super();
38 }
39
40 public HomeInfo getHomeInfo() {
41 return homeInfo;
42 }
43
44 public void setHomeInfo(HomeInfo homeInfo) {
45 this.homeInfo = homeInfo;
46 }
47
48 public Long getHomeUserID() {
49 return homeUserID;
50 }
51
52 public void setHomeUserID(Long homeUserID) {
53 this.homeUserID = homeUserID;
54 }
55
56 public Long getUserID() {
57 return userID;
58 }
59
60 public void setUserID(Long userID) {
61 this.userID = userID;
62 }
63
64 public Long getHomeID() {
65 return homeID;
66 }
67
68 public void setHomeID(Long homeID) {
69 this.homeID = homeID;
70 }
71
72 @Override
73 public String toString() {
74 return "HomeUser [homeUserID=" + homeUserID + ", userID=" + userID + ", homeID=" + homeID + "]";
75 }
76
77 }
自定义的联查结果实体类
1 package management.entity.carandhome;
2
3 import java.io.Serializable;
4 import java.math.BigDecimal;
5 import java.util.ArrayList;
6 import java.util.Date;
7 import java.util.HashSet;
8 import java.util.List;
9 import java.util.Set;
10
11 import javax.persistence.Entity;
12 import javax.persistence.FetchType;
13 import javax.persistence.GeneratedValue;
14 import javax.persistence.Id;
15 import javax.persistence.JoinColumn;
16 import javax.persistence.JoinTable;
17 import javax.persistence.ManyToMany;
18 import javax.persistence.OneToMany;
19 import javax.persistence.OneToOne;
20 import javax.persistence.Table;
21
22 import org.hibernate.annotations.NotFound;
23 import org.hibernate.annotations.NotFoundAction;
24
25 import com.alibaba.fastjson.annotation.JSONField;
26 import management.entity.paymentfee.LifeFee;
27 import management.entity.paymentfee.ManageFee;
31 public class HomeUserAppVO implements Serializable {
32
33 /**
34 *
35 */
36 private static final long serialVersionUID = 1L;
37
38 public HomeUserAppVO() {
39 super();
40 } // 这个构造方法必须有， 且要与后面的联查hql语句对应
41 public HomeUserAppVO(Long homeID, String homeNo, String homeUnit, String homeRoom, String mobileNo,
42 String homeState, String homeNature, String homeFloor, String homeLo) {
43 super();
44 this.homeID = homeID;
45 this.homeNo = homeNo;
46 this.homeUnit = homeUnit;
47 this.homeRoom = homeRoom;
48 this.mobileNo = mobileNo;
49 this.homeState = homeState;
50 this.homeNature = homeNature;
51 this.homeFloor = homeFloor;
52 this.homeLo = homeLo;
53 }
54 private Long homeID;
55
56 // 楼号
57 private String homeNo;
58
59 // 单元号
60 private String homeUnit;
61
62 // 房间号
63 private String homeRoom;
64
65 // 手机号
66 private String mobileNo;
67
68
69 // 房屋状态
70 private String homeState;
71
72 // 房产性质
73 private String homeNature;
74
75 // 楼层
76 private String homeFloor;
77
78 // 房屋位置
79 private String homeLo;
80 // 用户角色（房主，家人，租客）
81 private String familyRelationship;
82 public Long getHomeID() {
83 return homeID;
84 }
85 public void setHomeID(Long homeID) {
86 this.homeID = homeID;
87 }
88 public String getHomeNo() {
89 return homeNo;
90 }
91 public void setHomeNo(String homeNo) {
92 this.homeNo = homeNo;
93 }
94 public String getHomeUnit() {
95 return homeUnit;
96 }
97 public void setHomeUnit(String homeUnit) {
98 this.homeUnit = homeUnit;
99 }
100 public String getHomeRoom() {
101 return homeRoom;
102 }
103 public void setHomeRoom(String homeRoom) {
104 this.homeRoom = homeRoom;
105 }
106 public String getMobileNo() {
107 return mobileNo;
108 }
109 public void setMobileNo(String mobileNo) {
110 this.mobileNo = mobileNo;
111 }
112 public String getHomeState() {
113 return homeState;
114 }
115 public void setHomeState(String homeState) {
116 this.homeState = homeState;
117 }
118 public String getHomeNature() {
119 return homeNature;
120 }
121 public void setHomeNature(String homeNature) {
122 this.homeNature = homeNature;
123 }
124 public String getHomeFloor() {
125 return homeFloor;
126 }
127 public void setHomeFloor(String homeFloor) {
128 this.homeFloor = homeFloor;
129 }
130 public String getHomeLo() {
131 return homeLo;
132 }
133 public void setHomeLo(String homeLo) {
134 this.homeLo = homeLo;
135 }
136 public String getFamilyRelationship() {
137 return familyRelationship;
138 }
139 public void setFamilyRelationship(String familyRelationship) {
140 familyRelationship = familyRelationship;
141 }
142 @Override
143 public String toString() {
144 return "HomeUserAppVO [homeID=" + homeID + ", homeNo=" + homeNo + ", homeUnit=" + homeUnit + ", homeRoom="
145 + homeRoom + ", mobileNo=" + mobileNo + ", homeState=" + homeState + ", homeNature=" + homeNature
146 + ", homeFloor=" + homeFloor + ", homeLo=" + homeLo + ", FamilyRelationship=" + familyRelationship
147 + "]";
148 }
149
150 }
2.实体类建好，这里我们直接写持久层代码
package management.dao.carandhome;
import java.math.BigDecimal;
import java.util.Date;
import java.util.List;
import java.util.Set;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Repository;
import management.dao.BaseDao;
import management.entity.carandhome.HomeInfo;
import management.entity.carandhome.HomeUserAppVO;
import management.vo.carHome.HomeInfoVO;
@Repository
public interface HomeInfoDao extends BaseDao<HomeInfo> {
//联查，返回自定义对象，使用hql语句. 这里需要注意三点【1.new 全类路径名(属性1，属性2) 2.属性名称要与实体类一一对应，大小写都不能差，否则会报异常 3.自定义类的构造方法里的字段要与这里一一对应】
@Query(
value = "select new management.entity.carandhome.HomeUserAppVO(h.homeID,h.homeNo,h.homeUnit,h.homeRoom,"
+ "h.mobileNo,h.homeState,h.homeNature,h.homeFloor,h.homeLo) from HomeInfo h , HomeUser hu where h.homeID=hu.homeID"
+ " and hu.userID=:id")
List<HomeUserAppVO> findHomeInfoByUserId(@Param("id") Long id);
// 原生sql联查语句写法，但是返回对象是一个object【】，因为使用了原生语句，只能自己再去一一对应，然后封装到自己的业务bean中。
@Query(
value = "SELECT " + " h.*, t.countUser " + "FROM " + " ( " + " SELECT "
+ " hu.HomeID homeID, " + " count(hu.UserID) countUser " + " FROM " + " ( "
+ " SELECT " + " hu.HomeID homeID " + " FROM " + " t_ss_w_home_user hu "
+ " WHERE " + " hu.UserID = :userID " + " ) t "
+ " LEFT JOIN t_ss_w_home_user hu ON hu.HomeID = t.homeID " + " GROUP BY "
+ " hu.HomeID " + " ) t " + "LEFT JOIN t_ss_w_home h ON t.homeID = h.HomeID",
nativeQuery = true)
List<Object[]> findByUserIdAndCountUser(@Param("userID") Long userID);
}
4.再写原生的sql时，别名 如果不能使用，需要在连接mysql配置时 增加 useOldAliasMetadataBehavior=true（有此问题的需要加，没有的就不用，我的版本不用，这里顺带提一下）
url: jdbc:mysql://mysql:3306/property_manager?useUnicode=true&characterEncoding=utf-8&useOldAliasMetadataBehavior=true
原文地址：https://www.cnblogs.com/ANCAN-RAY/p/8521344.html
时间： 2024-10-14 21:13:59