Question

在我重新安装手机上的应用程序之前，一切都很好。如有必要，我可以发布我的代码。我不知道是什么原因引起了这个问题。这是logcat：

04-19 19:31:48.799: E/AndroidRuntime(24963): FATAL EXCEPTION: main
04-19 19:31:48.799: E/AndroidRuntime(24963): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.classorganizer/com.example.classorganizer.Monday}: android.database.sqlite.SQLiteException: no such table: diaries: , while compiling: SELECT * FROM diaries
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.os.Handler.dispatchMessage(Handler.java:99)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.os.Looper.loop(Looper.java:130)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.app.ActivityThread.main(ActivityThread.java:3687)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at java.lang.reflect.Method.invokeNative(Native Method)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at java.lang.reflect.Method.invoke(Method.java:507)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at dalvik.system.NativeStart.main(Native Method)
04-19 19:31:48.799: E/AndroidRuntime(24963): Caused by: android.database.sqlite.SQLiteException: no such table: diaries: , while compiling: SELECT * FROM diaries
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteCompiledSql.compile(SQLiteCompiledSql.java:92)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteCompiledSql.<init>(SQLiteCompiledSql.java:65)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:83)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:49)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:42)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1501)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1380)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1334)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1416)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at com.cookbook.data.MyDB.getdiaries(MyDB.java:66)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at com.example.classorganizer.Monday$DiaryAdapter.getdata(Monday.java:86)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at com.example.classorganizer.Monday$DiaryAdapter.<init>(Monday.java:80)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at com.example.classorganizer.Monday.onCreate(Monday.java:68)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
04-19 19:31:48.799: E/AndroidRuntime(24963):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615)
04-19 19:31:48.799: E/AndroidRuntime(24963):    ... 11 more

这是我的MyDBhelper文件：

package com.cookbook.data;





import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;


public class MyDBhelper extends SQLiteOpenHelper{


private static final String CREATE_TABLE="create table "+
Constants.TABLE_NAME+" ("+
Constants.KEY_ID+" integer primary key autoincrement, "+
Constants.TITLE_NAME+" text not null, "+
Constants.CONTENT_NAME+" text not null, "
;
private SQLiteDatabase db;



// database initialization
public MyDBhelper(Context context, String name, CursorFactory factory,
                    int version) {
    super(context, name, factory, version);

}



@Override
public void onCreate(SQLiteDatabase db) {
    Log.v("MyDBhelper onCreate","Creating all the tables");



    try {
        this.db = db;
        db.execSQL(CREATE_TABLE);

        for(int i=1; i <= 48; i++) { insertdiary(db, "free",""); }

    }

    catch(SQLiteException ex) {
        Log.v("Create table exception", ex.getMessage());

    }

}


// Saves a diary entry to the database as name-value pairs in ContentValues instance
            // then passes the data to the SQLitedatabase instance to do an insert
            public long insertdiary(SQLiteDatabase db, String title, String content)
            {


                try{
                    ContentValues newTaskValue = new ContentValues();
                    newTaskValue.put(Constants.TITLE_NAME,  title);
                    newTaskValue.put(Constants.CONTENT_NAME, content);

                    return db.insert(Constants.TABLE_NAME,  null, newTaskValue);

                } catch(SQLiteException ex) {
                    Log.v("Insert into database exception caught",
                            ex.getMessage());
                    return -1;
                }

            }

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion,
                        int newVersion) {
    Log.w("TaskDBAdapter", "Upgrading from version "+oldVersion
                            +" to "+newVersion
                            +", which will destroy all old data");
    db.execSQL("drop table if exists "+Constants.TABLE_NAME);
    onCreate(db);
}




}

这是MyDB文件：

package com.cookbook.data;


import com.example.classorganizer.Diary;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.util.Log;

public class MyDB {
private static final String TABLE_NAME = null;
private static final String KEY_ID = null;
private SQLiteDatabase db;
private final Context context;
private final MyDBhelper dbhelper;



// Initializes MyDBHelper instance
public MyDB(Context c){

    context = c;
    dbhelper = new MyDBhelper(context, Constants.DATABASE_NAME, null,
                                        Constants.DATABASE_VERSION);

}


// Closes the database connection
public void close()
{
    db.close();

}

// Initializes a SQLiteDatabase instance using MyDBhelper
public void open() throws SQLiteException
{

    try {
        db = dbhelper.getWritableDatabase();
    } catch(SQLiteException ex) {
        Log.v("Open database exception caught", ex.getMessage());
        db = dbhelper.getReadableDatabase();
    }

}

// updates a diary entry (existing row)
    public boolean updateDiaryEntry(String title, long rowId)
    {

        ContentValues newValue = new ContentValues();
        newValue.put(Constants.TITLE_NAME, title);

        return db.update(Constants.TABLE_NAME, newValue, Constants.KEY_ID + "=" + rowId, null)>0;

    }

// Reads the diary entries from database, saves them in a Cursor class and returns it from the method
public Cursor getdiaries()
{
    Cursor c = db.query(Constants.TABLE_NAME, null, null,
                        null, null, null, null);
    return c;
}


}

这是在列表中输出新创建的行的文件：

package com.example.classorganizer;


import java.util.ArrayList;

import android.app.ListActivity;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

import com.cookbook.data.Constants;
import com.cookbook.data.MyDB;




public class Monday extends ListActivity {



private static final int MyMenu = 0;
MyDB dba;
DiaryAdapter myAdapter;

private class MyDiary{
    public MyDiary(String t, String c){
        title=t;
        content=c;

        ListView listView = new ListView(Monday.this);
        listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
                new EditListItemDialog(view.getContext()).show();

                return true;


            }
        });


}

    public String title;
    public String content;

}
@Override
protected void onCreate(Bundle savedInstanceState) {
    dba = new MyDB(this);
    dba.open();
    setContentView(R.layout.fragment_monday);





    super.onCreate(savedInstanceState);
    myAdapter = new DiaryAdapter(this);
    this.setListAdapter(myAdapter);
}



private class DiaryAdapter extends BaseAdapter {
    private LayoutInflater mInflater;
    private ArrayList<MyDiary> fragment_monday;
    public DiaryAdapter(Context context) {
        mInflater = LayoutInflater.from(context);
        fragment_monday = new ArrayList<MyDiary>();
        getdata();


    }

    public void getdata(){
        Cursor c = dba.getdiaries();
        startManagingCursor(c);
        if(c.moveToFirst()){
            do{
                String title =
                        c.getString(c.getColumnIndex(Constants.TITLE_NAME));
                String content =
                        c.getString(c.getColumnIndex(Constants.CONTENT_NAME));

                MyDiary temp = new MyDiary(title,content);
                fragment_monday.add(temp);
            } while(c.moveToNext());
        }

    }



    @Override
    public int getCount() {return fragment_monday.size();}
    public MyDiary getItem(int i) {return fragment_monday.get(i);}
    public long getItemId(int i) {return i;}
    public View getView(int arg0, View arg1, ViewGroup arg2) {
        final ViewHolder holder;

        View v = arg1;
        if ((v == null) || (v.getTag() == null)) {
            v = mInflater.inflate(R.layout.diaryrow,  null);
            holder = new ViewHolder();
            holder.mTitle = (TextView)v.findViewById(R.id.name);

            v.setTag(holder);
        } else {
            holder = (ViewHolder) v.getTag();
        }

        holder.mdiary = getItem(arg0);
        holder.mTitle.setText(holder.mdiary.title);


        v.setTag(holder);

        return v;


    }

    public class ViewHolder {
        MyDiary mdiary;
        TextView mTitle;


    }

}




/** Called when the user clicks the Edit button */
public void visitDiary(View view) {
    Intent intent = new Intent(this, Diary.class);
    startActivity(intent);
}
/** Called when the user clicks the back button */
public void visitSchedule(View view) {
    Intent intent = new Intent(this, DisplayScheduleScreen.class);
    startActivity(intent);
}


}

Answer 1

问题在于这一行：

Constants.CONTENT_NAME+" text not null, "

删除最后一个逗号并添加右括号：

Constants.CONTENT_NAME+" text not null)"

Answer 2

以下是您的问题：SQLiteException: no such table: diaries。

在尝试从中进行SELECT之前，检查表是否已在数据库中创建。

Answer 3

这是你的问题：

no such table: diaries

问题很可能是，因为您说您重新安装了该应用，但您尚未创建数据库或您正在选择的表格。

编辑：现在您发布了数据库创建脚本，语法错误：

private static final String CREATE_TABLE="create table "+
Constants.TABLE_NAME+" ("+
Constants.KEY_ID+" integer primary key autoincrement, "+
Constants.TITLE_NAME+" text not null, "+
Constants.CONTENT_NAME+" text not null, "
;

您在Constants.TABLE_NAME打开后离开括号。在Constants.CONTENT_NAME之后，写下：+" text not null)"

Answer 4

您的onCreate()有SQL语法问题，但您抓住SQLiteException，因此框架认为表创建成功。您不应该在sqlite帮助程序生命周期方法中捕获异常。如果出现问题，应该将其传播给调用者，而不是默默地忽略。

至于语法问题，

private static final String CREATE_TABLE="create table "+
Constants.TABLE_NAME+" ("+
Constants.KEY_ID+" integer primary key autoincrement, "+
Constants.TITLE_NAME+" text not null, "+
Constants.CONTENT_NAME+" text not null, "
;

应该是

private static final String CREATE_TABLE="create table "+
Constants.TABLE_NAME+" ("+
Constants.KEY_ID+" integer primary key autoincrement, "+
Constants.TITLE_NAME+" text not null, "+
Constants.CONTENT_NAME+" text not null)"
;

尝试列出数据库条目时应用程序崩溃

4 个答案: