我无法处理我的申请中的问题。有两个类用于处理数据库，但它们只是创建数据库并在其中创建一个表，但基础未填充并在严重错误中查询数据库，表明数据库为空。请帮帮我
第一个DB类：
package ru.psdevteam.syndicttest.app;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class SynDB extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "synonyms.db";
public static final String TABLE_NAME = "words";
private static final int DATABASE_VERSION = 1;
public static final String WordID = "_id";
public static final String Word = "word";
private static final String SQL_CREATE_ENTRIES = "CREATE TABLE "
+ TABLE_NAME + " (" + WordID + " INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL ,"
+ Word + " text NOT NULL); ";
public static final String SQL_INSERT_WORDS = "INSERT INTO " + TABLE_NAME + " (_id,word) " + "VALUES " + "(1,'а'),(2,'же'),(3,'да'),(4,'напротив'),(5,'но'),(6,'ан'),(7,'однако'),(8,'инак'),(9,'следовательно'),(10,'потом')";
private static final String SQL_DELETE_ENTRIES = "DROP TABLE IF EXISTS "
+ TABLE_NAME;
public SynDB(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(SQL_CREATE_ENTRIES);
db.execSQL(SQL_INSERT_WORDS);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w("LOG_TAG", "Обновление базы данных с версии " + oldVersion
+ " до версии " + newVersion + ", которое удалит все старые данные");
db.execSQL(SQL_DELETE_ENTRIES);
onCreate(db);
}
}
第二个DB类：
package ru.psdevteam.syndicttest.app;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class IdDB extends SQLiteOpenHelper {
//constants
private static final String DATABASE_NAME = "synonyms.db";
public static final String TABLE_NAME_2 = "synonyms";
private static final int DATABASE_VERSION = 1;
public static final String StringID = "s_id";
public static final String SynWordID = "w_id";
// test database with test data inside
private static final String SQL_CREATE_ENTRIES = "CREATE TABLE "
+ TABLE_NAME_2 + " (" + SynWordID + " INTEGER NOT NULL ,"
+ StringID + " INTEGER NOT NULL); ";
public static final String SQL_INSERT_IDS = "INSERT INTO " + TABLE_NAME_2 + " (w_id,s_id) " + "VALUES " + "(1,2),(1,3),(1,4),(1,5),(1,6),(1,7),(1,8),(1,9),(1,10)";
private static final String SQL_DELETE_ENTRIES = "DROP TABLE IF EXISTS " + TABLE_NAME_2;
public IdDB(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase dbsyn) {
dbsyn.execSQL(SQL_CREATE_ENTRIES);
dbsyn.execSQL(SQL_INSERT_IDS);
}
@Override
public void onUpgrade(SQLiteDatabase dbsyn, int oldSynVersion, int newSynVersion) {
Log.w("LOG_TAG", "Обновление базы данных с версии " + oldSynVersion
+ " до версии " + newSynVersion + ", которое удалит все старые данные");
dbsyn.execSQL(SQL_DELETE_ENTRIES);
onCreate(dbsyn);
}
}
和MainActivity：
package ru.psdevteam.syndicttest.app;
import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
public class MainActivity extends Activity implements OnClickListener {
final String LOG_TAG = "myLogs";
IdDB idh;
SynDB sqh;
SQLiteDatabase sqdb, iddb;
Button btnOk;
EditText etWord;
String eWord;
String[] syns = { "Synonym1", "Synonym2", "Synonym3", "Synonym4", "Synonym5", "Synonym6", // it's just for example. I must change it for display list of synonyms from DB
"Synonym7", "Synonym8", "Synonym9", "Synonym10", "Synonym11" };
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
etWord = (EditText) findViewById(R.id.etWord);
btnOk = (Button) this.findViewById(R.id.btnOk);
ListView lvMain = (ListView) findViewById(R.id.lvMain);
btnOk.setOnClickListener(btnOkListener);
//initialize our class-cover IdDB
idh = new IdDB(this);
// initialize our class-cover SynDB
sqh = new SynDB(this);
// we need db to read and write
sqdb = sqh.getWritableDatabase();
iddb = idh.getWritableDatabase();
// создаем адаптер
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
android.R.layout.simple_list_item_1, syns);
// присваиваем адаптер списку
lvMain.setAdapter(adapter);
}
public OnClickListener btnOkListener = new OnClickListener(){
@Override
public void onClick(View v) {
eWord = etWord.getText().toString();
switch (v.getId()){
//if "Ок" is pressed (it is the only one)
case R.id.btnOk:
//i want to unite all my queries and out in listView result of FinalQuery
String query = "SELECT " + SynDB.WordID +" FROM " + SynDB.TABLE_NAME + " WHERE " + SynDB.Word + " ='" + eWord + "'"; // first query: here you enter the word and search it's ID in the table
String IdQuery = "SELECT " + IdDB.SynWordID +"," + IdDB.StringID + " FROM " + IdDB.TABLE_NAME_2 + " WHERE " + IdDB.SynWordID + " ='" + 1 + "' " + "or " + IdDB.StringID + " ='" + 1 + "'";// second query: here ID from first table compare with ID from second table
String FinalQuery = "SELECT " + SynDB.Word + " FROM " + SynDB.TABLE_NAME + " WHERE " + SynDB.WordID + " IN " + "('1','2','3','4')" ; // wrong final query. here should be selected already sorted by ID synonyms
Cursor cursor3 = iddb.rawQuery(IdQuery, null);
Cursor cursorLast = sqdb.rawQuery(FinalQuery, null);
Log.d(LOG_TAG, "--- Rows in mytable: ---");
// делаем запрос всех данных из таблицы words, получаем Cursor
Cursor cursor2 = sqdb.rawQuery(query, null);
// ставим позицию курсора на первую строку выборки
// если в выборке нет строк, вернется false
if (cursor2.moveToFirst()) {
// определяем номера столбцов по имени в выборке
int idColIndex = cursor2.getColumnIndex("_id");
int wordColIndex = cursor2.getColumnIndex("word");
do {
// получаем значения по номерам столбцов и пишем все в лог
Log.d(LOG_TAG,
"_id = " + cursor2.getInt(idColIndex) +
", word = " + cursor2.getString(wordColIndex));
// переход на следующую строку
// а если следующей нет (текущая - последняя), то false - выходим из цикла
} while (cursor2.moveToNext());
} else
Log.d(LOG_TAG, "0 rows");
cursor2.close();
break;
default:
break;
} // close switch
} // close onClick
};
protected void onStop() {
// TODO Auto-generated method stub
super.onStop();
// закрываем соединения с базой данных
sqdb.close();
sqh.close();
}
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public void onClick(View view) {
}
}
logcat的：
05-08 09:08:32.559 1583-1583/ru.psdevteam.syndicttest.app W/KeyCharacterMap﹕ Can't open keycharmap file
05-08 09:08:32.559 1583-1583/ru.psdevteam.syndicttest.app W/KeyCharacterMap﹕ Error loading keycharmap file '/system/usr/keychars/AT_Translated_Set_2_keyboard.kcm.bin'. hw.keyboards.65540.devname='AT Translated Set 2 keyboard'
05-08 09:08:32.559 1583-1583/ru.psdevteam.syndicttest.app W/KeyCharacterMap﹕ Using default keymap: /system/usr/keychars/qwerty.kcm.bin
05-08 09:08:42.309 1583-1583/ru.psdevteam.syndicttest.app D/myLogs﹕ --- Rows in mytable: ---
05-08 09:08:42.309 1583-1583/ru.psdevteam.syndicttest.app E/CursorWindow﹕ Bad request for field slot 0,-1. numRows = 1, numColumns = 1
05-08 09:08:42.309 1583-1583/ru.psdevteam.syndicttest.app D/AndroidRuntime﹕ Shutting down VM
05-08 09:08:42.309 1583-1583/ru.psdevteam.syndicttest.app W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0xb574d4f0)
05-08 09:08:42.319 1583-1583/ru.psdevteam.syndicttest.app E/AndroidRuntime﹕ FATAL EXCEPTION: main
java.lang.IllegalStateException: get field slot from row 0 col -1 failed
at android.database.CursorWindow.getString_native(Native Method)
at android.database.CursorWindow.getString(CursorWindow.java:338)
at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:49)
at ru.psdevteam.syndicttest.app.MainActivity$1.onClick(MainActivity.java:106)
at android.view.View.performClick(View.java:2485)
at android.view.View$PerformClick.run(View.java:9081)
at android.os.Handler.handleCallback(Handler.java:587)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3683)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
at dalvik.system.NativeStart.main(Native Method)
05-08 09:08:46.649 1583-1583/ru.psdevteam.syndicttest.app I/Process﹕ Sending signal. PID: 1583 SIG: 9
答案 0 :(得分：1)
您的查询是
String query = "SELECT " + SynDB.WordID +" FROM " + SynDB.TABLE_NAME + " WHERE " + SynDB.Word + " ='" + eWord + "'"; // first query: here you enter the word and search it's ID in the table
只选择一列。
然后你尝试在那里获取两列：
int idColIndex = cursor2.getColumnIndex("_id");
int wordColIndex = cursor2.getColumnIndex("word");
// ...
Log.d(LOG_TAG,
"_id = " + cursor2.getInt(idColIndex) +
", word = " + cursor2.getString(wordColIndex));
getColumnIndex()返回-1。
将word添加到SELECT以将其包含在游标中。
答案 1 :(得分：-1)
public static final String SQL_INSERT_WORDS = "INSERT INTO " + TABLE_NAME + " (_id,word) " + "VALUES " + "(1,'а'),(2,'же'),(3,'да'),(4,'напротив')...
_id字段为AUTOINCREMENT。 不要在查询中提供它。就像
public static final String SQL_INSERT_WORDS = "INSERT INTO " + TABLE_NAME + " (word) " + "VALUES " + "('а'),('же'),('да'),('напротив')...