我试图从日期格式如下的表格中选择一些日期：
package nori.beta.musicplayer;
import android.app.Activity;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.graphics.Color;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.SeekBar;
import android.widget.TextView;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Random;
import nori.beta.musicplayer.Class.BlurBuilder;
import nori.beta.musicplayer.Fragment.Playlist;
import nori.beta.musicplayer.Fragment.Utilities;
public class MainActivity extends Activity {
private ImageView bg; // blured backgroud of size of screen
private ImageView cover; // small image in center of activity that plays song
private BlurBuilder blured; // class to blur image for background
private SeekBar
progressBar; // Creating seekbar that show progress of song and allow us scroll and rewind song
private ImageButton
play_pause_stopButton; //on click do 1.play/2.paues/3.stop for all change icon
private MediaPlayer player; // Player that play music
private Handler mHandler = new Handler(); //Handler that help with refreshing progressBar
private Utilities utils; //Change seconds into min + sec
ArrayList<File> mySongs; // list of music file
ArrayList<Song> songsInfo; //list of music file with extract information about them
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// init all GUI staff
initGUI();
setButtons();
}
@Override
protected void onResume() {
super.onResume();
// init Database and rest of gui staff that need database
// Here have u data of all file and chosen song and can u make to play song
}
private void initGUI() {
// Image Part
bg = (ImageView) findViewById(R.id.main_background);
cover = (ImageView) findViewById(R.id.cover_image);
blured = new BlurBuilder();
//Buttons
play_pause_stopButton = (ImageButton) findViewById(R.id.play_pause_stop_button);
progressBar = (SeekBar) findViewById(R.id.progressBar);
player = new MediaPlayer();
utils = new Utilities();
mySongs = findSongs(Environment.getExternalStorageDirectory());
songsInfo = new ArrayList<Song>();
for (File f : mySongs) {
songsInfo.add(new Song(f));
}
//progressBar.setOnSeekBarChangeListener(this);
}
private ArrayList<File> findSongs(File root) {
ArrayList<File> al = new ArrayList<File>();
File[] files = root.listFiles();
/**
* findSongs Search for music file in memory
*
* for each file in memory
* 1.if is that file a folder , then take all file then give it in method findSongs
* and with requrency
* 2.Else if that file end with .mp3 or .wav ,then add to list
*/
for (File singleFile : files) {
if (singleFile.isDirectory() && !singleFile.isHidden()) {
al.addAll(findSongs(singleFile));
//Log.e("findsongs","Folder");
} else {
if (singleFile.getName().endsWith(".mp3") || singleFile.getName().endsWith(".wav")) {
al.add(singleFile);
Log.e("FileInfo.GetSong", singleFile.getName().toString());
}
}
}
return al;
}
private void setButtons() {
play_pause_stopButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) { //Play/Pause song button clicked
playSong(0);
}
});
progressBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() { //Using progress bar to scrolling song
@Override
public void onStopTrackingTouch(SeekBar progressBar) {
}
@Override
public void onStartTrackingTouch(SeekBar progressBar) {
}
@Override
public void onProgressChanged(SeekBar progressBar, int progress, boolean fromUser) { //When user move progress bar song go to moment that user choosed
if (player != null && fromUser) {
player.seekTo(progress * 1000);
}
}
});
player.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
@Override
public void onCompletion(MediaPlayer player) { //When song ended playing
playSong(0);
}
});
}
public void updateProgressBar() {
mHandler.postDelayed(mUpdateTimeTask, 100); //Updating progressBar every 100ms
}
private Runnable mUpdateTimeTask = new Runnable() {
public void run() { //Updating time of song and progressbar
long totalDuration = player.getDuration();
long currentDuration = player.getCurrentPosition();
// Updating progress bar
int mCurrentPosition = player.getCurrentPosition() / 1000;
progressBar.setProgress(mCurrentPosition);
// Running this thread after 100 milliseconds
mHandler.postDelayed(this, 100);
}
};
// set it in all changes of the privius songs <#-- Krzysiek -->
private void setBackground(int i) {
//setting the back image and cover image to the chosen song
if (songsInfo.get(i).getBackground() != null) {
bg.setImageBitmap(blured.blur(this, songsInfo.get(i).getBackground()));
cover.setImageBitmap(songsInfo.get(i).getBackground());
Log.i("FileInfo.SetCover", "Set cover of " + songsInfo.get(i).getName());
}
}
public void playSong(int index) {
try {
player.reset();
player.setDataSource(songsInfo.get(index).getPath()); //Getting song with proper index from list
player.prepare();
player.start(); //Playing prepared song
// Displaying Song title
String songTitle = songsInfo.get(index).getTitle();
String songArtist = songsInfo.get(index).getArtist();
setBackground(index);
// Changing Button Image to pause image
play_pause_stopButton.setImageResource(R.drawable.pause);
// set Progress bar values
progressBar.setProgress(0);
progressBar.setMax(player.getDuration() / 1000);
// Updating progress bar
updateProgressBar();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
请注意，日期可以是AM或PM，但是当我尝试从表中执行简单的SELECT时，例如：
android:configChanges="orientation|screenSize"
我收到错误：
14-APR-14 10.35.00.0000000000 AM
01-NOV-16 02.43.00.0000000000 PM
我一直试图让这项工作停留一段时间，但没有运气。这里的任何帮助将不胜感激。
答案 0 :(得分：2)
来自你的评论：
这实际上是一个时间戳;不是一个字符串。时间戳（6）准确
您可以使用TIMESTAMP literal：
SELECT *
FROM MyTable
WHERE MyDate > TIMESTAMP '2016-12-31 08:00:00';
答案 1 :(得分：1)
有几个问题。
您的输入显然是字符串，因为它们有10个小数位，Oracle中的时间戳最多只有9个。然后，一小段时间的字符串无法转换为to_date的日期 - 您需要使用to_timestamp，否则您需要删除所有小数部分。在下面的解决方案中，我只删除最后一个（十分之一）小数，因为表中可能有非零小数部分 - 尽管不在您发布的样本中。
然后，你的格式掩码有yyyy，但你的输入只有两位数（这可能意味着93代表1993而不是2093，所以正确使用的是rr而不是yy）。您在输入使用:
.
最后，甚至不要用字符串格式比较日期：在字符串比较中，01-JAN-2015在20-NOV-2013之前。
你可能想要这样的东西：
select mydate
from (
select '14-APR-14 10.35.00.0000000000 AM' as mydate from dual
union all
select '01-NOV-16 02.43.00.0000000000 PM' from dual
) mytable
where to_timestamp(substr(mydate, 1, 28) || substr(mydate, -3), 'dd-MON-rr hh.mi.ss.ff AM')
> to_timestamp('31-DEC-2016 08:00:00 AM', 'dd-MON-yyyy hh:mi:ss AM');
此查询正确编译，并且在输出中不产生任何行（原因很明显）。
注意：在评论中，您（OP）说mydate字段是timestamp（6）数据类型。很难相信（你显示十位小数），但如果它确实是一个时间戳或日期，那么你不需要将它包装在任何to_timestamp或to_date函数中，它应该是站立的单独在不平等的左边。