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? ??? ??? MySQL ???? Java? MySQL? ?? ??? ?????? ??? ??????

Java? MySQL? ?? ??? ?????? ??? ??????

Dec 10, 2024 am 12:53 AM

How Do Java and MySQL Handle Datetimes and Timestamps?

Java?? MySQL ?? ?? ? ?????? ?? ??

Java ???????? MySQL ??????? ?? ??? ?????? ?? ???? ?? ??? ??????. ??? ??? ??? ? ?? ???? ??? ???? ????? ?????. ??.

Java ??

Java?? ??? ????? ??? ?? ??? ??? ??? ???? ????? java.util.Date ???? ???? ?????.

MySQL ??

MySQL?? ? ?? ?? ?? ? ?? ??? ??? ????.

  • DATE: ?? ??(?, ?, ?)? ?????.
  • TIME: ?? ??(?, ?, ?)? ?????.
  • TIMESTAMP: ? ?? ?? ?????. ?? ? ?? ??.

Java? MySQL? ?? ??

MySQL?? TIMESTAMP ?? Java? ???? ??? java.sql? ?????. .Timestamp ??? java.util.Date? ?? ??????. preparedStatement? ???? MySQL? ??? ??? ? setTimestamp() ???? ???? ???? ?? Timestamp ??? ???? ???.

?? ??

????? Java?? MySQL ?? ?? ? ?????? ?? ???? ??? ??? ??????. ??:

import java.sql.*;

public class DatetimeExample {

    public static void main(String[] args) throws SQLException {
        // Establish a connection to the MySQL database
        Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/database_name", "username", "password");

        // Get a timestamp object representing the current date and time
        Timestamp timestamp = new Timestamp(System.currentTimeMillis());

        // Create a prepared statement to insert data into the database
        PreparedStatement preparedStatement = connection.prepareStatement("INSERT INTO events (event_date, event_time) VALUES (?, ?)");

        // Set the timestamp value as the first parameter
        preparedStatement.setTimestamp(1, timestamp);

        // Set the second parameter as the time part of the timestamp
        preparedStatement.setTime(2, new Time(timestamp.getTime()));

        // Execute the insert statement
        preparedStatement.executeUpdate();

        // Retrieve the inserted data using a result set
        ResultSet resultSet = preparedStatement.executeQuery("SELECT event_date, event_time FROM events WHERE event_id = (SELECT LAST_INSERT_ID())");

        // Get the timestamp from the result set
        Timestamp retrievedTimestamp = resultSet.getTimestamp("event_date");

        // Convert the timestamp to a Java date
        Date retrievedDate = new Date(retrievedTimestamp.getTime());

        // Print the retrieved date and time
        System.out.println("Retrieved date: " + retrievedDate);
        System.out.println("Retrieved time: " + new Time(retrievedTimestamp.getTime()));
    }
}

? ???? Timestamp ??? ???? ??? ?? ??? ?? MySQL ??????? ???? ?? Java? ?? ? ?? ??? ???? ??? ?????.

? ??? Java? MySQL? ?? ??? ?????? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!

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