Spring JDBC - 建立查詢

以下示例將演示如何使用Insert查詢和Spring JDBC建立查詢。我們將向Student表中插入一些記錄。

語法

String insertQuery = "insert into Student (name, age) values (?, ?)";
jdbcTemplateObject.update( insertQuery, name, age);

其中，

• insertQuery - 包含佔位符的插入查詢。

• jdbcTemplateObject - 用於將學生物件插入資料庫的StudentJDBCTemplate物件。

示例

為了理解上面提到的與Spring JDBC相關的概念，讓我們編寫一個插入查詢的示例。為了編寫我們的示例，讓我們準備好一個可用的Eclipse IDE，並使用以下步驟建立一個Spring應用程式。

StudentDAO.java

以下是資料訪問物件介面檔案StudentDAO.java的內容。

package com.tutorialspoint;

import java.util.List;
import javax.sql.DataSource;

public interface StudentDAO {
   /** 
    * This is the method to be used to initialize
    * database resources ie. connection.
   */
   public void setDataSource(DataSource ds);
   
   /** 
    * This is the method to be used to create
    * a record in the Student table.
   */
   public void create(String name, Integer age);
   
   /** 
    * This is the method to be used to list down
    * all the records from the Student table.
   */
   public List<Student> listStudents();   
}

Student.java

以下是Student.java檔案的內容。

package com.tutorialspoint;

// Student POJO for Student Table
public class Student {
   private Integer age;
   private String name;
   private Integer id;

   // setter/getter methods
   public void setAge(Integer age) {
      this.age = age;
   }
   public Integer getAge() {
      return age;
   }
   public void setName(String name) {
      this.name = name;
   }
   public String getName() {
      return name;
   }
   public void setId(Integer id) {
      this.id = id;
   }
   public Integer getId() {
      return id;
   }
}

StudentMapper.java

以下是StudentMapper.java檔案的內容。

package com.tutorialspoint;

import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;

// Row Mapper Object to map Student table entry with Student Object
public class StudentMapper implements RowMapper<Student> {
   public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
      Student student = new Student();
      student.setId(rs.getInt("id"));
      student.setName(rs.getString("name"));
      student.setAge(rs.getInt("age"));
      return student;
   }
}

StudentJDBCTemplate.java

以下是為已定義的DAO介面StudentDAO編寫的實現類檔案StudentJDBCTemplate.java。

package com.tutorialspoint;

import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;

// DAO instance to persist Student values
public class StudentJDBCTemplate implements StudentDAO {
   private DataSource dataSource;
   private JdbcTemplate jdbcTemplateObject;
   
   // set the datasource and jdbctemplate
   public void setDataSource(DataSource dataSource) {
      this.dataSource = dataSource;
      this.jdbcTemplateObject = new JdbcTemplate(dataSource);
   }
   
   // persist a new student
   public void create(String name, Integer age) {
      String insertQuery = "insert into Student (name, age) values (?, ?)";
      jdbcTemplateObject.update( insertQuery, name, age);
      System.out.println("Created Record Name = " + name + " Age = " + age);
      return;
   }
   
   // get list of all students
   public List<Student> listStudents() {
      String SQL = "select * from Student";
      List <Student> students = jdbcTemplateObject.query(SQL, new StudentMapper());
      return students;
   }
}

MainApp.java

以下是MainApp.java檔案的內容。

package com.tutorialspoint;

import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import com.tutorialspoint.StudentJDBCTemplate;

public class MainApp {
   public static void main(String[] args) {
      // Create the application context by reading Beans.xml  
      ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");

      // Create the JDBCTemplate instance from spring context
      StudentJDBCTemplate studentJDBCTemplate = (StudentJDBCTemplate)context.getBean("studentJDBCTemplate");
      
      // create and persist students	  
      System.out.println("------Records Creation--------" );
      studentJDBCTemplate.create("Zara", 11);
      studentJDBCTemplate.create("Nuha", 2);
      studentJDBCTemplate.create("Ayan", 15);

      // get all students
      System.out.println("------Listing Multiple Records--------" );
      List<Student> students = studentJDBCTemplate.listStudents();
      
      // print students
      for (Student record : students) {
         System.out.print("ID : " + record.getId() );
         System.out.print(", Name : " + record.getName() );
         System.out.println(", Age : " + record.getAge());
      }  
   }
}

Beans.xml

以下是配置檔案Beans.xml的內容。

<?xml version = "1.0" encoding = "UTF-8"?>
<beans xmlns = "http://www.springframework.org/schema/beans"
   xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance" 
   xsi:schemaLocation = "http://www.springframework.org/schema/beans
   http://www.springframework.org/schema/beans/spring-beans-3.0.xsd ">

   <!-- Initialization for data source -->
   <bean id = "dataSource" 
      class = "org.springframework.jdbc.datasource.DriverManagerDataSource">
      <property name = "driverClassName" value = "com.mysql.cj.jdbc.Driver"/>
      <property name = "url" value = "jdbc:mysql://:3306/TEST"/>
      <property name = "username" value = "root"/>
      <property name = "password" value = "admin"/>
   </bean>

   <!-- Definition for studentJDBCTemplate bean -->
   <bean id = "studentJDBCTemplate" 
      class = "com.tutorialspoint.StudentJDBCTemplate">
      <property name = "dataSource" ref = "dataSource" />    
   </bean>
</beans>

輸出

建立原始檔和bean配置檔案後，讓我們執行應用程式。如果應用程式一切正常，它將列印以下訊息。

------Records Creation--------
Created Record Name = Zara Age = 11
Created Record Name = Nuha Age = 2
Created Record Name = Ayan Age = 15
------Listing Multiple Records--------
ID : 1, Name : Zara, Age : 11
ID : 2, Name : Nuha, Age : 2
ID : 3, Name : Ayan, Age : 15