JDBC事务

JDBC

```statement
		String database="jdbc:mysql://localhost:3306/people?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8";
        String name="root";
        String password="123456";
        try {
            Class.forName("com.mysql.jdbc.Driver");
            Connection connection = DriverManager.getConnection(database, name, password);
            Statement statement = connection.createStatement();
            String sql="select * from _people";
            ResultSet resultSet = statement.executeQuery(sql);
            while (resultSet.next()){
                System.out.println(resultSet.getObject("id")+"\t"+resultSet.getObject("name")+"\t"
                +resultSet.getObject("age")+"\t"+resultSet.getObject("address"));
            }
            resultSet.close();
            statement.close();
            connection.close();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException throwables) {
            throwables.printStackTrace();
        }

preparedStatement
public class Test1 {
    public static void main(String[] args) throws Exception {
        String database="jdbc:mysql://localhost:3306/people?useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8";
        String name="root";
        String password="123456";
        Class.forName("com.mysql.jdbc.Driver");
        Connection connection = DriverManager.getConnection(database, name, password);
        String sql="insert into _people(id, name, age, address) values (?,?,?,?);";
        PreparedStatement preparedStatement = connection.prepareStatement(sql);
        preparedStatement.setInt(1,3);
        preparedStatement.setString(2,"xiaogong");
        preparedStatement.setInt(3,21);
        preparedStatement.setString(4,"深圳");
        int i = preparedStatement.executeUpdate();
        if (i>0){
            System.out.println("插入成功");
        }else {
            System.out.println("插入失败");
        }
    }
}

事务

要么成功，要么都失败
ACID原则：保证数据的安全 

1. 开启事务
2. 事务提交
3. 事务回滚
4. 关闭事务

转账：
A：1000
B：1000
A（900） --100–> B（1100）