在《基於Spring Boot，使用JPA操作Sql Server數據庫完成CRUD》，《基於Spring Boot，使用JPA調用Sql Server數據庫的存儲過程並返回記錄集合》完成了CRUD，調用存儲過程查詢數據。
很多復雜的情況下，會存在要直接執行SQL來獲取數據。
通過“EntityManager”創建NativeQuery方法來執行動態SQL。
1.查詢結果集映射
在包“com.kxh.example.demo.domain”下的“Contact”實體上編寫命名的結果集映射，因為可以寫很多映射。
@SqlResultSetMapping注解即為映射。
name參數，可以為結果集映射取個名字。
entities參數，用來說明把Entity和查詢的結果字段進行關聯說明。
package com.kxh.example.demo.domain;import javax.persistence.Entity;
import javax.persistence.EntityResult;
import javax.persistence.FieldResult;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.NamedStoredProcedureQueries;
import javax.persistence.NamedStoredProcedureQuery;
import javax.persistence.ParameterMode;
import javax.persistence.SqlResultSetMapping;
import javax.persistence.StoredProcedureParameter;@Entity
@SqlResultSetMapping(
name = "conatctMapping",
entities = @EntityResult(
entityClass = Contact.class,
fields = {
@FieldResult(name = "name", column = "name"),
@FieldResult(name = "phone", column = "phone"),
@FieldResult(name = "mail", column = "mail")})
)
@NamedStoredProcedureQueries({
@NamedStoredProcedureQuery(
name = "getContactsLikeName",
procedureName = "proc_get_contacts_like_name",
resultClasses = { Contact.class },
parameters = {
@StoredProcedureParameter(
mode = ParameterMode.IN,
name = "name",
type = String.class)
}
)
})
public class Contact {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private long id;</span><span style="color: #0000ff;">private</span><span style="color: #000000;"> String name; </span><span style="color: #0000ff;">private</span><span style="color: #000000;"> String phone; </span><span style="color: #0000ff;">private</span><span style="color: #000000;"> String mail; </span><span style="color: #0000ff;">public</span><span style="color: #000000;"> Contact() { </span><span style="color: #0000ff;">super</span><span style="color: #000000;">(); } </span><span style="color: #0000ff;">public</span><span style="color: #000000;"> Contact(String name, String phone, String mail) { </span><span style="color: #0000ff;">super</span><span style="color: #000000;">(); </span><span style="color: #0000ff;">this</span>.name =<span style="color: #000000;"> name; </span><span style="color: #0000ff;">this</span>.phone =<span style="color: #000000;"> phone; </span><span style="color: #0000ff;">this</span>.mail =<span style="color: #000000;"> mail; } </span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">long</span><span style="color: #000000;"> getId() { </span><span style="color: #0000ff;">return</span> <span style="color: #0000ff;">this</span><span style="color: #000000;">.id; } </span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span> setId(<span style="color: #0000ff;">long</span><span style="color: #000000;"> value) { </span><span style="color: #0000ff;">this</span>.id =<span style="color: #000000;"> value; } </span><span style="color: #0000ff;">public</span><span style="color: #000000;"> String getName() { </span><span style="color: #0000ff;">return</span> <span style="color: #0000ff;">this</span><span style="color: #000000;">.name; } </span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> setName(String value) { </span><span style="color: #0000ff;">this</span>.name =<span style="color: #000000;"> value; } </span><span style="color: #0000ff;">public</span><span style="color: #000000;"> String getPhone() { </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> phone; } </span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> setPhone(String value) { </span><span style="color: #0000ff;">this</span>.phone =<span style="color: #000000;"> value; } </span><span style="color: #0000ff;">public</span><span style="color: #000000;"> String getMail() { </span><span style="color: #0000ff;">return</span> <span style="color: #0000ff;">this</span><span style="color: #000000;">.mail; } </span><span style="color: #0000ff;">public</span> <span style="color: #0000ff;">void</span><span style="color: #000000;"> setMail(String value) { </span><span style="color: #0000ff;">this</span>.mail =<span style="color: #000000;"> value; }}
3.通過業務對象調用
在包“com.kxh.example.demo.service”下的類“ContactsService”中添加執行函數。
通過"EntityManager"創建NativeQuery函數，第一參數是Sql，第二個參數就是上面定義的結果集映射名。
然后傳入查詢條件參數，設置最大返回結果記錄數，獲取查詢結果集。
package com.kxh.example.demo.service;import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.StoredProcedureQuery;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;import com.kxh.example.demo.domain.Contact;
@Component
public class ContactsService {
@Autowired
private EntityManager entityManager;@SuppressWarnings(</span>"unchecked"<span style="color: #000000;">) </span><span style="color: #0000ff;">public</span> List<Contact><span style="color: #000000;"> findAllViaProc(String name) { StoredProcedureQuery storedProcedureQuery </span>= <span style="color: #0000ff;">this</span>.entityManager.createNamedStoredProcedureQuery("getContactsLikeName"<span style="color: #000000;">); storedProcedureQuery.setParameter(</span>"name"<span style="color: #000000;">, name); storedProcedureQuery.execute(); </span><span style="color: #0000ff;">return</span><span style="color: #000000;"> storedProcedureQuery.getResultList(); }@SuppressWarnings("unchecked")
public List<Contact> findAllByViaQuery(String name) {
List<Contact> contacts = this.entityManager
.createNativeQuery("select name, phone, mail from contact where name like :name", "conatctMapping")
.setParameter("name", name)
.setMaxResults(5)
.getResultList();</span><span style="color: #0000ff;">return</span></span><span style="color: #000000;"><span style="background-color: #ffff00;"> contacts; }</span>}
4.通過RestController向外提供服務
增加一個新的訪問路徑映射，在處理方法中調用contactsService.findAllByViaQuery(nameWhere)獲取查詢結果集。
package com.kxh.example.demo.controller;import java.util.ArrayList;
import java.util.List;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;import com.kxh.example.demo.dao.ContactsRepository;
import com.kxh.example.demo.domain.Contact;
import com.kxh.example.demo.service.ContactsService;@RestController
@RequestMapping("/contacts")
public class ContactsController {@Autowired ContactsService contactsService;</span><span style="color: #008000;">//省略</span>//通過動態sql查
@RequestMapping(value="/query/viadnq/likename", method=RequestMethod.GET)
public List<Contact> findContactsUseDyanamicQueryLikeName(String name) {
System.out.println("kxh1");
String nameWhere = org.apache.commons.lang.StringUtils.join(new String[]{"%", name, "%"}, "");
List<Contact> contacts = contactsService.findAllByViaQuery(nameWhere);
if(contacts == null) {
System.out.println("kxh4");
return new ArrayList<Contact>();
} else {
System.out.println("kxh5");
return contacts;
}
}
}
End
原文地址：https://www.cnblogs.com/kongxianghai/p/7575988.html