Create Query

以下示例将演示如何在Spring JDBC的帮助下使用Insert查询创建查询。 我们将在学生表中插入一些记录。

语法 (Syntax)

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

Where,

• insertQuery - 插入具有占位符的查询。

• jdbcTemplateObject - 要在数据库中插入学生对象的StudentJDBCTemplate对象。

要理解与Spring JDBC相关的上述概念，让我们编写一个插入查询的示例。 要编写我们的示例，让我们使用一个可用的Eclipse IDE，并使用以下步骤创建一个Spring应用程序。

以下是数据访问对象接口文件StudentDAO.java 。

package cn.xnip;
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();   
}

以下是Student.java文件的内容。

package cn.xnip;
public class Student {
   private Integer age;
   private String name;
   private Integer id;
   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;
   }
}

以下是StudentMapper.java文件的内容。

package cn.xnip;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.springframework.jdbc.core.RowMapper;
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;
   }
}

以下是定义的DAO接口StudentJDBCTemplate.java的实现类文件StudentJDBCTemplate.java 。

package cn.xnip;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
public class StudentJDBCTemplate implements StudentDAO {
   private DataSource dataSource;
   private JdbcTemplate jdbcTemplateObject;
   public void setDataSource(DataSource dataSource) {
      this.dataSource = dataSource;
      this.jdbcTemplateObject = new JdbcTemplate(dataSource);
   }
   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;
   }
   public List<Student> listStudents() {
      String SQL = "select * from Student";
      List <Student> students = jdbcTemplateObject.query(SQL, new StudentMapper());
      return students;
   }
}

以下是MainApp.java文件的内容。

package cn.xnip;
import java.util.List;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import cn.xnip.StudentJDBCTemplate;
public class MainApp {
   public static void main(String[] args) {
      ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");
      StudentJDBCTemplate studentJDBCTemplate = 
         (StudentJDBCTemplate)context.getBean("studentJDBCTemplate");
      System.out.println("------Records Creation--------" );
      studentJDBCTemplate.create("Zara", 11);
      studentJDBCTemplate.create("Nuha", 2);
      studentJDBCTemplate.create("Ayan", 15);
      System.out.println("------Listing Multiple Records--------" );
      List<Student> students = studentJDBCTemplate.listStudents();
      for (Student record : students) {
         System.out.print("ID : " + record.getId() );
         System.out.print(", Name : " + record.getName() );
         System.out.println(", Age : " + record.getAge());
      }  
   }
}

以下是配置文件Beans.xml 。

<?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.jdbc.Driver"/>
      <property name = "url" value = "jdbc:mysql://localhost:3306/TEST"/>
      <property name = "username" value = "root"/>
      <property name = "password" value = "admin"/>
   </bean>
   <!-- Definition for studentJDBCTemplate bean -->
   <bean id = "studentJDBCTemplate" 
      class = "cn.xnip.StudentJDBCTemplate">
      <property name = "dataSource" ref = "dataSource" />    
   </bean>
</beans>

完成源和bean配置文件的创建后，让我们运行应用程序。 如果您的应用程序一切正常，它将打印以下消息。

------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