3 Idiots
传统JDBC批量插入方法：
1.Java代码中使用For循环直接插入SQL数据如：execute()或executeUpdate()方法。
2.借助于Statement、Prestatement对象的批处理方法addBatch
public class jdbcUtil {
// 处理数据库事务，批量操作需要手动提交事务
public static void commit(Connection connection){
if (null!=connection){
try {
connection.commit();
}catch (SQLException e){
e.printStackTrace();
}
}
}
//事务的回滚
public static void rollback(Connection connection){
if (null!=connection){
try {
connection.rollback();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
// 事务的开始
public static void begin(Connection connection) {
if (null != connection) {
try {
connection.setAutoCommit(false);
} catch (SQLException e) {
e.printStackTrace();
}
}
}
/**
* 获取连接方法
* @Param
* @Return
*/
public static Connection getConnection() throws Exception {
Properties properties = new Properties();
InputStream is = jdbcUtil.class.getClassLoader().getResourceAsStream("jdbc.properties");
//jdbc文件内容以 流 的方式加载到properties文件中
properties.load(is);
String driver=properties.getProperty("driver");
String username=properties.getProperty("username");
String password=properties.getProperty("password");
String url=properties.getProperty("url");
System.out.println(driver+":"+password);
Class.forName(driver);
return DriverManager.getConnection(url,username,password);
}
/**
* 通用的关闭资源的方法
* @Param connection
* @Param statement
* @Param resultSet
*/
public static void closeResources(Connection connection, Statement statement, ResultSet resultSet){
if (null!=connection){
try {
connection.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (null!=statement){
try {
statement.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (null!=resultSet){
try {
resultSet.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
}
使用for循环插入
public class BatchTestOne {
public static void main(String[] args) throws Exception {
Connection connection=null;
PreparedStatement preparedStatement=null;
connection = jdbcUtil.getConnection();
jdbcUtil.begin(connection); //autocommit false
String sql = "insert into t_user(username,password) values(?,?)";
preparedStatement=connection.prepareStatement(sql);
long beginTime = System.currentTimeMillis();
for (int i=0;i<10000;i++){
preparedStatement.setString(1,"user"+(i+1));
preparedStatement.setString(2,"pwd"+(i+1));
preparedStatement.executeUpdate();
}
jdbcUtil.commit(connection);
long endTime = System.currentTimeMillis();
System.out.println("total time:"+(endTime-beginTime));//4150
}
}
使用addBatch批处理方式插入
public class BatchTestTwo {
public static void main(String[] args) throws Exception {
Connection connection=null;
PreparedStatement preparedStatement=null;
connection = jdbcUtil.getConnection();
jdbcUtil.begin(connection);
String sql = "insert into t_user(username,password) values(?,?)";
preparedStatement=connection.prepareStatement(sql);
long beginTime = System.currentTimeMillis();
for (int i=0;i<10000;i++){
preparedStatement.setString(1,"batch"+(i+1));
preparedStatement.setString(2,"num"+(i+1));
preparedStatement.addBatch();
if ((i+1)%1000==0){
preparedStatement.executeBatch();
preparedStatement.clearBatch();
}
}
jdbcUtil.commit(connection);
long endTime = System.currentTimeMillis();
System.out.println("total time:"+(endTime-beginTime));//1817
}
}
可以看出：使用批处理的方式要比普通的for循环要快很多。mybatis封装了jdbc，所以mybatis的批处理方式类似于addBatch
MyBatis进行批量插入的方法
MySQL添加多条数据的方式
insert into person(username,email,gender) VALUES("zhangsan","[email protected]","F"),("lisi","[email protected]","F")
或者
insert into person(username,email,gender) VALUES("tom","[email protected]","F");
insert into person(username,email,gender) VALUES("jerry","[email protected]","F")
1.借助foreach标签使用 insert into table values
public class Person {
private Integer id;
private String username;
private String email;
private String gender;
public Person(String username, String email, String gender) {
this.id = id;
this.username = username;
this.email = email;
this.gender = gender;
}
}
public interface PersonMapper {
void addPersons(@Param("persons") List persons);
}
insert into person(username,email,gender) VALUES
(#{person.username},#{person.email},#{person.gender})
测试
public class MyBatisTest {
public static SqlSessionFactory sqlSessionFactory = null;
public static SqlSessionFactory getSqlSessionFactory() {
if (sqlSessionFactory == null) {
String resource = "mybatis-config.xml";
try {
Reader reader = Resources.getResourceAsReader(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
} catch (IOException e) {
e.printStackTrace();
}
}
return sqlSessionFactory;
}
public void processMybatisBatch()
{
SqlSession sqlSession = this.getSqlSessionFactory().openSession();
PersonMapper personMapper = sqlSession.getMapper(PersonMapper.class);
List persons=new ArrayList();
for (int i = 0; i <1000 ; i++)
{
Person person=new Person("jerry"+i,"email@"+i,"f");
persons.add(person);
}
personMapper.addPersons(persons);
sqlSession.commit();
}
public static void main(String[] args) {
new MyBatisTest().processMybatisBatch();
}
}
2.借助MySQL数据库连接属性 allowMultiQueries=true
driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/mybatis?allowMultiQueries=true
username=root
password=123456
然后，只需要修改上面PersonMapper.xml中的insert语句
insert into person(username,email,gender) VALUES
(#{person.username},#{person.email},#{person.gender})
3.基于SqlSession的ExecutorType进行批量添加
public interface PersonMapper {
void addPerson(Person person);
}
insert into person(username,email,gender) VALUES (#{username},#{email},#{gender})
测试
public void testBatchForExecutor() {
SqlSession sqlSession = this.getSqlSessionFactory().openSession(ExecutorType.BATCH);
PersonMapper personMapper = sqlSession.getMapper(PersonMapper.class);
for (int i = 0; i <10 ; i++)
{
personMapper.addPerson(new Person("Tom","email@"+i,"F"));
}
sqlSession.commit();
sqlSession.close();
}
总结
传统JDBC批量插入方法：
1.利用for循环进行插入的方式存在严重效率问题，需要频繁获取Session，获取连接。
2.使用批处理，代码和SQL的耦合度高，代码量较大。
MyBatis进行批量插入的方法：
1.MySQL下批量保存的两种方式，建议使用第一种
2.借助于Executor的Batch批量添加，可与Spring框架整合，数据量大的时候，我们一般采用这种方式。