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私はEclipseとAndroidプログラミングでは新しいです、私は私のデータベース接続に問題があります。よく私は多くのリンクを見つけ、よく私は2つのクラスを投稿します。誰かが間違いを見つけることができれば。私が持っているデータベースはsqliteで作られていて、それはそのandroid_metadataと質問テーブルを持っています。エミュレータで実行すると、Aboutフォームを開いたときにメッセージが表示される "DrymVyzion（プロセスdv.qtest.dvyzual）によるアプリケーションクイズテストが予期せず停止しました。もう一度やり直してください。"エラーです日食で ：androidデータベース、ファイルから読み取る
quizData.java
package dv.qtest.dvyzual;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
/** Helper to the database, manages versions and creation */
public class quizData extends SQLiteOpenHelper {
private static final String DB_PATH = "/data/data/dv.qtest.dvyzual/databases/";
private static final String DB_NAME = "q.db";
private static final int DATABASE_VERSION = 1;
private SQLiteDatabase myDataBase;
private final Context myContext;
// Table name
public static final String TABLE = "questions";
// Columns
public static final String qid = "_id";
public static final String question = "question";
public static final String qone = "qone";
public static final String qtwo = "qtwo";
public static final String qthree = "qthree";
public static final String qanswer = "qanswer";
public quizData(Context context) {
super(context, DB_NAME, null, DATABASE_VERSION);
this.myContext = context;
}
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
if(dbExist){
}else{
//By calling this method and empty database will be created into the default system path
//of your application so we are gonna be able to overwrite that database with our database.
this.getReadableDatabase();
try {
this.close(); // testing
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
//database does't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
package dv.qtest.dvyzual;
import java.io.IOException;
import android.app.Activity;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.widget.TextView;
public class About extends Activity {
/** Called when the activity is first created. */
private quizData eventsData = new quizData(About.this);
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.about);
Cursor cursor = getEvents();
showEvents(cursor);
try {
eventsData.createDataBase();
} catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
eventsData.openDataBase();
}catch(SQLException sqle){
throw sqle;
}
}
@Override
public void onDestroy() {
eventsData.close();
}
private Cursor getEvents() {
SQLiteDatabase db = eventsData.getReadableDatabase();
Cursor cursor = db.query("questions", new String[]{"_id","question","qone", "qtwo", "qthree", "qanswer"}, null, null, null, null, null);
startManagingCursor(cursor);
return cursor;
}
private void showEvents(Cursor cursor) {
StringBuilder ret = new StringBuilder("Saved Events:\n\n");
while (cursor.moveToNext()) {
long id = cursor.getLong(0);
String q = cursor.getString(1);
String q1 = cursor.getString(2);
ret.append(id + ": " + q + ": " + q1 + "\n");
}
TextView tv = new TextView(this);
tv.setText(ret);
setContentView(tv);
}
}
About.java嘆願：ここ
01-08 22:50:42.292: E/AndroidRuntime(1059): Uncaught handler: thread main exiting due to uncaught exception
01-08 22:50:42.312: E/AndroidRuntime(1059): java.lang.RuntimeException: Unable to start activity ComponentInfo{dv.qtest.dvyzual/dv.qtest.dvyzual.About}: android.database.sqlite.SQLiteException: no such table: questions: , while compiling: SELECT _id, question, qone, qtwo, qthree, qanswer FROM questions
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2401)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2417)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.app.ActivityThread.access$2100(ActivityThread.java:116)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.os.Handler.dispatchMessage(Handler.java:99)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.os.Looper.loop(Looper.java:123)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.app.ActivityThread.main(ActivityThread.java:4203)
01-08 22:50:42.312: E/AndroidRuntime(1059): at java.lang.reflect.Method.invokeNative(Native Method)
01-08 22:50:42.312: E/AndroidRuntime(1059): at java.lang.reflect.Method.invoke(Method.java:521)
01-08 22:50:42.312: E/AndroidRuntime(1059): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
01-08 22:50:42.312: E/AndroidRuntime(1059): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
01-08 22:50:42.312: E/AndroidRuntime(1059): at dalvik.system.NativeStart.main(Native Method)
01-08 22:50:42.312: E/AndroidRuntime(1059): Caused by: android.database.sqlite.SQLiteException: no such table: questions: , while compiling: SELECT _id, question, qone, qtwo, qthree, qanswer FROM questions
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.database.sqlite.SQLiteProgram.native_compile(Native Method)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.database.sqlite.SQLiteProgram.compile(SQLiteProgram.java:110)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:59)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:49)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:49)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1118)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1006)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:964)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1041)
01-08 22:50:42.312: E/AndroidRuntime(1059): at dv.qtest.dvyzual.About.getEvents(About.java:46)
01-08 22:50:42.312: E/AndroidRuntime(1059): at dv.qtest.dvyzual.About.onCreate(About.java:22)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
01-08 22:50:42.312: E/AndroidRuntime(1059): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)
は私の2クラスであります私が間違っていることを誰かが見つけることができたら助けてくれる、私は何時間も努力している！ ところで、DBパスのないファイルからではなく、データベースで動作します。だから、おそらく問題は、私はdb helperを正しく設定していないということですか？何か案は？
おかげで、私は問題がないので、私はまだ同じ問題を抱えている、これを試してみました。 （ – NeoXRated