java框架之Spring(3)-JDBC模板使用&事务管理

时间:2023-03-08 18:36:52
java框架之Spring(3)-JDBC模板使用&事务管理

下面内容使用到的 jar 包下载

JDBC模板使用

入门

1、导包,如要导入 Spring 的基本开发包、数据库驱动包、Spring 提供的 JDBC 模板包,如下:

java框架之Spring(3)-JDBC模板使用&事务管理

2、测试:

@Test
public void test(){
    // 创建连接池对象
    DriverManagerDataSource driverManagerDataSource = new DriverManagerDataSource();
    driverManagerDataSource.setDriverClassName("com.mysql.jdbc.Driver");
    driverManagerDataSource.setUrl("jdbc:mysql:///test");
    driverManagerDataSource.setUsername("root");
    driverManagerDataSource.setPassword("root");
    // 创建 JDBC 模板对象
    JdbcTemplate jdbcTemplate = new JdbcTemplate(driverManagerDataSource);
    // 通过模板对象操作数据库
    jdbcTemplate.update("insert into user values(null,?,?)", "bob", 123);
}

将模板交给Spring

<?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.xsd">
    <bean name="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql:///test"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>

    <bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>
</beans>

applicationContext.xml

package com.zze.test;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.datasource.DriverManagerDataSource;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class Demo {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    @Test
    public void test() {
        jdbcTemplate.update("update user set password=? where username=?", "345", "bob");
    }

}

test

使用第三方连接池

DBCP配置

额外导入 jar 包:

java框架之Spring(3)-JDBC模板使用&事务管理

配置:

<?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.xsd">
    <!--DBCP 配置-->
    <bean name="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql:///test"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>

    <bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>
</beans>

applicationContext.xml

C3P0配置

额外导入 jar 包:

java框架之Spring(3)-JDBC模板使用&事务管理

配置:

<?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.xsd">
    <!--C3P0连接池配置-->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql:///test"/>
        <property name="user" value="root"/>
        <property name="password" value="root"/>
    </bean>

    <bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>
</beans>

applicationContext.xml

抽取JDBC配置到属性文件

有如下属性文件:

jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///test
jdbc.username=root
jdbc.password=root

jdbc.properties

方式一:

<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location" value="classpath:jdbc.properties"/>
</bean>

方式二:

<context:property-placeholder location="classpath:jdbc.properties"/>

接下来就可以通过如下方式引用到属性文件中的属性,例:

<bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
    <property name="driverClass" value="${jdbc.driverClass}"/>
    <property name="jdbcUrl" value="${jdbc.url}"/>
    <property name="user" value="${jdbc.username}"/>
    <property name="password" value="${jdbc.password}"/>
</bean>

CRUD操作

package com.zze.test;

import com.zze.bean.User;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class Demo {
    @Autowired
    private JdbcTemplate jdbcTemplate;

    /**
     * 保存
     */
    @Test
    public void test1() {
        jdbcTemplate.update("insert into user values (null,?,?)", "bob", "123");
    }

    /**
     * 更新
     */
    @Test
    public void test2() {
        jdbcTemplate.update("update user set password=? where username=?", "346", "bob");
    }

    /**
     * 删除
     */
    @Test
    public void test3() {
        jdbcTemplate.update("delete from user where username=?", "bob");
    }

    /**
     * 查询首行首列
     */
    @Test
    public void test4() {
        Integer integer = jdbcTemplate.queryForObject("select COUNT(1) from user", Integer.class);
        System.out.println(integer);
    }

    /**
     * 查询一条数据封装到单个对象
     */
    @Test
    public void test5() {
        User user = jdbcTemplate.queryForObject("select * from user where username=?", new RowMapper<User>() {
            @Override
            public User mapRow(ResultSet rs, int rowNum) throws SQLException {
                User user = new User();
                user.setId(rs.getInt("id"));
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
                return user;
            }
        }, "bob");
        System.out.println(user);
    }

    /**
     * 查询多条记录封装到集合
     */
    @Test
    public void test6() {
        List<User> userList = jdbcTemplate.query("select * from user", new RowMapper<User>() {
            @Override
            public User mapRow(ResultSet rs, int rowNum) throws SQLException {
                User user = new User();
                user.setId(rs.getInt("id"));
                user.setUsername(rs.getString("username"));
                user.setPassword(rs.getString("password"));
                return user;
            }
        });
        System.out.println(userList);
    }

}

事务管理

事务回顾

参见【数据库事务了解一下】。

Spring事务管理API

  • PlatformTransactionManager:平台事务管理器

    接口,是 Spring 用于管理事务真正的对象。

    DataSourceTransactionManager:底层使用JDBC管理事务。

    HibernateTransactionManager:底层使用Hibernate管理事务。

  • TransactionDefinition:事务定义信息

    用于定义事务的相关的信息,隔离级别、超时信息、传播行为、是否只读。

  • TransactionStatus:事务的状态

    用于记录在事务管理过程中,事务的状态的对象。

上述API之间的关系:

Spring进行事务管理的时候,首先平台事务管理器根据事务定义信息进行事务的管理,在事务管理过程中,产生各种状态,将这些状态的信息记录到事务状态的对象中。

事务的传播行为

Spring 中提供了七种事务的传播行为,可分为如下三类:

  • 保证多个操作在同一个事务中:

    PROPAGATION_REQUIRED :默认值,如果A中有事务,使用A中的事务,如果A没有,创建一个新的事务,将操作包含进来

    PROPAGATION_SUPPORTS :支持事务,如果A中有事务,使用A中的事务。如果A没有事务,不使用事务。

    PROPAGATION_MANDATORY :如果A中有事务,使用A中的事务。如果A没有事务,抛出异常。

  • 保证多个操作不在同一个事务中:

    PROPAGATION_REQUIRES_NEW :如果A中有事务,将A的事务挂起(暂停),创建新事务,只包含自身操作。如果A中没有事务,创建一个新事务,包含自身操作。

    PROPAGATION_NOT_SUPPORTED :如果A中有事务,将A的事务挂起。不使用事务管理。

    PROPAGATION_NEVER :如果A中有事务,报异常。

  • 嵌套式事务:

    PROPAGATION_NESTED :嵌套事务,如果A中有事务,按照A的事务执行,执行完成后,设置一个保存点,执行B中的操作,如果没有异常,执行通过,如果有异常,可以选择回滚到最初始位置,也可以回滚到保存点。

搭建Spring的事务管理的环境

准备

创建 account 表并初始化如下数据:

java框架之Spring(3)-JDBC模板使用&事务管理

下面代码模拟一个转账场景:

package com.zze.dao;

public interface AccountDao {
    /**
     * 转出
     * @param username 转出账户的用户名
     * @param money 转出金额
     */
    void outMoney(String username,Double money);

    /**
     * 转入
     * @param username 转入账户的用户名
     * @param money 转入金额
     */
    void inMoney(String username, Double money);
}

com.zze.dao.AccountDao

package com.zze.dao.impl;

import com.zze.dao.AccountDao;
import org.springframework.jdbc.core.support.JdbcDaoSupport;

public class AccountDaoImpl extends JdbcDaoSupport implements AccountDao {
    @Override
    public void outMoney(String username, Double money) {
        this.getJdbcTemplate().update("update account set money=money-? where username=?", money, username);
    }

    @Override
    public void inMoney(String username, Double money) {
        this.getJdbcTemplate().update("update account set money=money+? where username=?", money, username);
    }
}

com.zze.dao.impl.AccountDaoImpl

package com.zze.service;

public interface AccountService {
    /**
     * 转账
     * @param usernameFrom 转账来源账户
     * @param usernameTo 转账目标账户
     * @param money 转账金额
     */
    void transfer(String usernameFrom,String usernameTo,Double money);
}

com.zze.service.AccountService

package com.zze.service.impl;

import com.zze.dao.AccountDao;
import com.zze.service.AccountService;

public class AccountServiceImpl implements AccountService {
    private AccountDao accountDao;

    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }

    @Override
    public void transfer(String usernameFrom, String usernameTo, Double money) {
        accountDao.outMoney(usernameFrom, money);
        accountDao.inMoney(usernameTo,money);
    }
}

com.zze.service.impl.AccountServiceImpl

jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql:///test
jdbc.username=root
jdbc.password=root

jdbc.properties

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       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.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <context:property-placeholder location="classpath:jdbc.properties"/>

    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driverClass}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--
    <bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    -->

    <bean name="accountDao" class="com.zze.dao.impl.AccountDaoImpl">
        <property name="dataSource" ref="dataSource"/>
        <!--<property name="jdbcTemplate" ref="jdbcTemplate"/>-->
    </bean>

    <bean name="accountService" class="com.zze.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
    </bean>
</beans>

applicationContext.xml

package com.zze.test;

import com.zze.service.AccountService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.annotation.Resource;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class Demo {
    @Resource(name = "accountService")
    private AccountService accountService;
    @Test
    public void test(){
        // zhangsan 给 lisi 转账 100
        accountService.transfer("zhangsan","lisi",100d);
    }
}

执行结果如下:

java框架之Spring(3)-JDBC模板使用&事务管理

test

编程式事务管理

1、修改配置:

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       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.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <context:property-placeholder location="classpath:jdbc.properties"/>

    <!--配置 C3p0 连接池-->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driverClass}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--配置事务管理器-->
    <bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--配置事务的管理的模板类-->
    <bean name="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate">
        <property name="transactionManager" ref="transactionManager"/>
    </bean>

    <bean name="accountDao" class="com.zze.dao.impl.AccountDaoImpl">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <bean name="accountService" class="com.zze.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
        <!--注入事务管理模板-->
        <property name="transactionTemplate" ref="transactionTemplate"/>
    </bean>
</beans>

applicationContext.xml

2、修改代码模拟异常并使用事务:

package com.zze.service.impl;

import com.zze.dao.AccountDao;
import com.zze.service.AccountService;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.TransactionCallbackWithoutResult;
import org.springframework.transaction.support.TransactionTemplate;

public class AccountServiceImpl implements AccountService {
    private AccountDao accountDao;
    private TransactionTemplate transactionTemplate;

    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }

    public void setTransactionTemplate(TransactionTemplate transactionTemplate) {
        this.transactionTemplate = transactionTemplate;
    }

    @Override
    public void transfer(String usernameFrom, String usernameTo, Double money) {
        transactionTemplate.execute(new TransactionCallbackWithoutResult() {
            @Override
            protected void doInTransactionWithoutResult(TransactionStatus transactionStatus) {
                accountDao.outMoney(usernameFrom, money);
                // 模拟过程中异常
                int i = 1 / 0;
                accountDao.inMoney(usernameTo, money);
            }
        });
    }
}

com.zze.service.impl.AccountServiceImpl

3、测试:

package com.zze.test;

import com.zze.service.AccountService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.annotation.Resource;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class Demo {
    @Resource(name = "accountService")
    private AccountService accountService;
    @Test
    public void test(){
        // zhangsan 给 lisi 转账 100
        accountService.transfer("zhangsan","lisi",100d);

        // 此时表数据将不会发生变化
    }
}

test

声明式事务管理-XML

1、修改配置:

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    <context:property-placeholder location="classpath:jdbc.properties"/>

    <!--配置 C3p0 连接池-->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driverClass}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--配置事务管理器-->
    <bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--配置事务的通知/增强-->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            <!--事务管理规则-->
            <tx:method name="save*" propagation="REQUIRED"/>
            <tx:method name="update*" propagation="REQUIRED"/>
            <tx:method name="delete*" propagation="REQUIRED"/>
            <tx:method name="find*" read-only="true"/>
            <!--
            name : 匹配方法名
            read-only : 为 true 时表示只做只读操作
            propagation : 事务的传播行为
            timeout : 事务过期时间,为 -1 时不会过期
            isolation : 事务的隔离级别
            -->
            <tx:method name="*" propagation="REQUIRED" isolation="DEFAULT" timeout="-1"/>
        </tx:attributes>
    </tx:advice>

    <!--AOP 配置-->
    <aop:config>
        <aop:pointcut id="pc_account" expression="execution(* com.zze.service.AccountService.*(..))"/>
        <aop:advisor advice-ref="txAdvice" pointcut-ref="pc_account"/>
    </aop:config>

    <bean name="accountDao" class="com.zze.dao.impl.AccountDaoImpl">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <bean name="accountService" class="com.zze.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
    </bean>
</beans>

applicationContext.xml

2、修改代码模拟异常:

package com.zze.service.impl;

import com.zze.dao.AccountDao;
import com.zze.service.AccountService;

public class AccountServiceImpl implements AccountService {
    private AccountDao accountDao;

    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }

    @Override
    public void transfer(String usernameFrom, String usernameTo, Double money) {
        accountDao.outMoney(usernameFrom, money);
        // 模拟过程中异常
        int i = 1 / 0;
        accountDao.inMoney(usernameTo, money);
    }
}

com.zze.service.impl.AccountServiceImpl

3、测试:

package com.zze.test;

import com.zze.service.AccountService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.annotation.Resource;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class Demo {
    @Resource(name = "accountService")
    private AccountService accountService;
    @Test
    public void test(){
        // zhangsan 给 lisi 转账 100
        accountService.transfer("zhangsan","lisi",100d);

        // 此时表数据将不会发生变化
    }
}

test

声明式事务管理-注解

1、修改配置:

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd">
    <context:property-placeholder location="classpath:jdbc.properties"/>

    <!--配置 C3p0 连接池-->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driverClass}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--配置事务管理器-->
    <bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--开启注解事务-->
    <tx:annotation-driven transaction-manager="transactionManager"/>

    <bean name="accountDao" class="com.zze.dao.impl.AccountDaoImpl">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <bean name="accountService" class="com.zze.service.impl.AccountServiceImpl">
        <property name="accountDao" ref="accountDao"/>
    </bean>
</beans>

applicationContext.xml

2、修改代码模拟异常并添加事务注解:

package com.zze.service.impl;

import com.zze.dao.AccountDao;
import com.zze.service.AccountService;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;

// 业务类上添加注解使用事务
@Transactional(isolation=Isolation.DEFAULT,propagation = Propagation.REQUIRED)
public class AccountServiceImpl implements AccountService {
    private AccountDao accountDao;

    public void setAccountDao(AccountDao accountDao) {
        this.accountDao = accountDao;
    }

    @Override
    public void transfer(String usernameFrom, String usernameTo, Double money) {
        accountDao.outMoney(usernameFrom, money);
        // 模拟过程中异常
        int i = 1 / 0;
        accountDao.inMoney(usernameTo, money);
    }
}

com.zze.service.impl.AccountServiceImpl

3、测试:

package com.zze.test;

import com.zze.service.AccountService;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import javax.annotation.Resource;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class Demo {
    @Resource(name = "accountService")
    private AccountService accountService;
    @Test
    public void test(){
        // zhangsan 给 lisi 转账 100
        accountService.transfer("zhangsan","lisi",100d);

        // 此时表数据将不会发生变化
    }
}

test