• Spring JDBC删除数据


    以下示例将展示如何使用Spring jdbc执行删除数据库表中的记录,这里演示如何删除指定student表中的记录。

    语法:

    String deleteQuery = "delete from Student where id = ?";
    jdbcTemplateObject.update(deleteQuery, id);
    
    Java

    在上面语法中 -

    • deleteQuery - 具有占位符的删除查询语句用来删除指定的学生信息。
    • jdbcTemplateObject - StudentJDBCTemplate 对象将 Student 对象从数据库中删除。

    创建项目

    要了解上面提到的Spring JDBC相关的概念,这里创建一个项目用来演示如何删除Student表中的数据记录。打开Eclipse IDE,并按照以下步骤创建一个名称为:DeleteQuery 的Spring应用程序项目。

    步骤说明

    1. 参考第一个Spring JDBC项目来创建一个Maven项目 - http://www.yiibai.com/springjdbc/first_application.html。
    2. 更新bean配置并运行应用程序。

    完整的项目结构如下所示 -

    文件 : pom.xml 的内容 -

    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
        <modelVersion>4.0.0</modelVersion>
        <groupId>com.yiibai</groupId>
        <artifactId>ReadQuery</artifactId>
        <version>0.0.1-SNAPSHOT</version>
        <packaging>jar</packaging>
        <url>http://maven.apache.org</url>
        <dependencies>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>3.8.1</version>
                <scope>test</scope>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.40</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-jdbc</artifactId>
                <version>4.1.0.RELEASE</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-context</artifactId>
                <version>4.1.4.RELEASE</version>
            </dependency>
        </dependencies>
    </project>
    

    以下是数据访问对象接口文件:StudentDAO.java的代码内容:

    package com.yiibai;
    
    import java.util.List;
    import javax.sql.DataSource;
    
    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 list down all the records from the
         * Student table.
         */
        public List<Student> listStudents();
    
        /**
         * This is the method to be used to delete a record from the Student table
         * corresponding to a passed student id.
         */
        public void delete(Integer id);
    }
    
    Java

    以下是文件:Student.java的代码内容:

    package com.yiibai;
    
    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;
        }
    }
    
    Java

    以下是文件:StudentMapper.java的代码内容:

    package com.yiibai;
    
    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;
        }
    }
    
    Java

    以下是实现类文件:StudentJDBCTemplate.java,它实现了接口StudentDAO.java
    以下是文件:StudentJDBCTemplate.java的代码内容:

    package com.yiibai;
    
    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 List<Student> listStudents() {
            String SQL = "select * from Student";
            List<Student> students = jdbcTemplateObject.query(SQL, new StudentMapper());
            return students;
        }
    
        public void delete(Integer id) {
            String SQL = "delete from Student where id = ?";
            jdbcTemplateObject.update(SQL, id);
            System.out.println("Deleted Record with ID = " + id);
            return;
        }
    
    }
    
    Java

    以下是程序执行入口文件:MainApp.java的代码内容:

    package com.yiibai;
    
    import java.util.List;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    import com.yiibai.StudentJDBCTemplate;
    
    public class MainApp {
        public static void main(String[] args) {
            ApplicationContext context = new ClassPathXmlApplicationContext("application-beans.xml");
    
            StudentJDBCTemplate studentJDBCTemplate = (StudentJDBCTemplate) context.getBean("studentJDBCTemplate");
    
            System.out.println("----Delete Record with ID = 2 -----");
            studentJDBCTemplate.delete(2);
    
            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());
            }
        }
    }
    
    Java

    以下是Bean和数据库配置文件:application-beans.xml的代码内容:

    <?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.jdbc.Driver" />
            <property name="url" value="jdbc:mysql://localhost:3306/test?characterEncoding=utf8&useSSL=true" />
            <property name="username" value="root" />
            <property name="password" value="123456" />
        </bean>
    
        <!-- Definition for studentJDBCTemplate bean -->
        <bean id="studentJDBCTemplate" class="com.yiibai.StudentJDBCTemplate">
            <property name="dataSource" ref="dataSource" />
        </bean>
    
    </beans>
    
    XML

    注意: application-beans.xml 文件的位置是:{workspace}/fistapp/src/main/java 目录,如果放置错了,程序可能会因为找不到此配置文件而出错。

    完成创建源代码和bean和数据库连接信息的文件配置后,运行应用程序。这里先简单说明一下运行的步骤,在项目名称(DeleteQuery)上点击右键,在弹出的菜单中选择:【Run As】-> 【Maven test】

    在运行测试成功后,应该会输出类似以下内容(含有 BUILD SUCCESS 的信息) 。
    接下来,点击类文件:MainApp.java 选择【Run As】->【Java Application】,如果应用程序一切正常,这将打印以下消息:

    ----Delete Record with ID = 2 -----
    Deleted Record with ID = 2
    ------Listing Multiple Records--------
    ID : 1, Name : Maxsu, Age : 19
    ID : 3, Name : Allen, Age : 27
    ID : 4, Name : Maxsu, Age : 19
    ID : 5, Name : Minsu, Age : 23
    ID : 6, Name : Allen, Age : 27
    ID : 7, Name : Maxsu, Age : 19
    ID : 8, Name : Minsu, Age : 23
    ID : 9, Name : Allen, Age : 27
    
    Shell
     
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  • 原文地址:https://www.cnblogs.com/borter/p/9608420.html
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