android - SQLite 不能在真实设备上运行，但可以在模拟器上运行

Question

我正在开发一个创建 SQLite onCreate 并查询记录的 Android 应用程序。一切都在我的 Android 模拟器上运行，但是当我在我的 Android 设备(Samsung Galaxy 7 Edge)上部署/调试时，数据库似乎是空的。

我已经在我的模拟器上测试过它并且工作正常。为什么在我的手机上似乎没有创建/查询 SQLite？我的 list 中是否需要额外的权限？

请帮忙。下面是我的代码

package com.example.android.cebuanotagalogtranslator;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class MainActivity extends AppCompatActivity {

    Button btn_clear;
    Button btn_translate_to_ceb;
    Button btn_translate_to_fil;
    EditText txt_input;
    EditText txt_output;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        //HABAGAT CONTROLS BEGIN
        btn_clear = (Button) findViewById(R.id.btn_clear);
        btn_translate_to_ceb = (Button) findViewById(R.id.btn_trans_to_ceb);
        btn_translate_to_fil = (Button) findViewById(R.id.btn_trans_to_fil);

        txt_input = (EditText) findViewById(R.id.input);
        txt_output = (EditText) findViewById(R.id.output);

        //HABAGAT : CLEAR BOTH TEXT
        btn_clear.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                txt_input.setText("");
                txt_output.setText("");
            }
        });

        //: FILIPINO -> CEBUANO
        btn_translate_to_ceb.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {


                try {
                    String textinput = txt_input.getText().toString();
                    textinput = "\""+ textinput +"\"";
                    String filToCebQuery = "SELECT ceb FROM filtoceb WHERE fil = "+ textinput+" "+"COLLATE NOCASE";
                    SQLiteDatabase DB = openOrCreateDatabase("filtoceb", MODE_PRIVATE, null);
                    //Cursor c = DB.rawQuery("SELECT * FROM filtoceb", null);
                    Cursor c = DB.rawQuery(filToCebQuery, null);


                    if (c!=null)
                    {
                        System.out.println("RESULT FOUND : FIL -> CEB");
                        try {
                            c.moveToFirst();
                            while(!c.isAfterLast()){
                                String result = c.getString(c.getColumnIndex("ceb"));
                                txt_output.setText(result);
                                c.moveToNext();
                            }
                        }
                        finally
                        {
                            c.close();
                        }
                    }


                } catch (Exception e) {
                    e.printStackTrace();
                }

            }
        });

        //: CEBUANO -> FILIPINO
        btn_translate_to_fil.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {


                try {
                    String textinput = txt_input.getText().toString();
                    textinput = "\""+ textinput +"\"";
                    String filToCebQuery = "SELECT fil FROM filtoceb WHERE ceb = "+ textinput+" "+"COLLATE NOCASE";
                    SQLiteDatabase DB = openOrCreateDatabase("filtoceb", MODE_PRIVATE, null);

                    Cursor c = DB.rawQuery(filToCebQuery, null);


                    if (c!=null)
                        System.out.println("RESULT FOUND : CEB -> FIL ");
                    {
                        try {
                            c.moveToFirst();
                            while(!c.isAfterLast()){
                                String result = c.getString(c.getColumnIndex("fil"));
                                txt_output.setText(result);
                                c.moveToNext();
                            }
                        }
                        finally
                        {
                            c.close();
                        }
                    }


                } catch (Exception e) {
                    e.printStackTrace();
                }

            }
        });

        // CREATE DB OPEN IF NOT CREATED YET
        try {
            SQLiteDatabase eventsDB = this.openOrCreateDatabase("filtoceb", MODE_PRIVATE, null);

            //DELETE INITIALIZE SETUP START CLEAN
            eventsDB.delete("filtoceb", "1", null);

            eventsDB.execSQL("CREATE TABLE IF NOT EXISTS filtoceb (fil VARCHAR, ceb VARCHAR)");
            eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Kumusta ka?','Kumusta ka?')");
            eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Maayo, salamat', 'Mabuti naman, salamat')");
            eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Unsay imong pangalan?',  'Ano pangalan mo?')");
            eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Unsay ngalan mo?', 'ano pangalan mo?')");
            eventsDB.execSQL("INSERT INTO filtoceb (CEB, FIL) values ('Maayo nga nagka-ila ta', 'Ikinagagalak kitang makilala')");
            eventsDB.execSQL("INSERT INTO filtoceb (CEB, FIL) values ('Palihug','Please')");          

            eventsDB.close();

        } catch (Exception e) {
            e.printStackTrace();
        }


    }


}

下面是我的 list :

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

Answer 1

我认为您的问题可能是由以下行的位置引起的。

        eventsDB.delete("filtoceb", "1", null);

在数据库不存在的情况下，这将导致失败，因为在您执行此行时表将不存在。

解决方案是将行移动到 after until after creating table。

所以代替:-

    try {
        SQLiteDatabase eventsDB = this.openOrCreateDatabase("filtoceb", MODE_PRIVATE, null);

        //DELETE INITIALIZE SETUP START CLEAN
        eventsDB.delete("filtoceb", "1", null);

        eventsDB.execSQL("CREATE TABLE IF NOT EXISTS filtoceb (fil VARCHAR, ceb VARCHAR)");
        eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Kumusta ka?','Kumusta ka?')");
        eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Maayo, salamat', 'Mabuti naman, salamat')");
        eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Unsay imong pangalan?',  'Ano pangalan mo?')");
        eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Unsay ngalan mo?', 'ano pangalan mo?')");
        eventsDB.execSQL("INSERT INTO filtoceb (CEB, FIL) values ('Maayo nga nagka-ila ta', 'Ikinagagalak kitang makilala')");
        eventsDB.execSQL("INSERT INTO filtoceb (CEB, FIL) values ('Palihug','Please')");          

        eventsDB.close();

    } catch (Exception e) {
        e.printStackTrace();
    }

使用:-

    try {
        SQLiteDatabase eventsDB = this.openOrCreateDatabase("filtoceb", MODE_PRIVATE, null);

        eventsDB.execSQL("CREATE TABLE IF NOT EXISTS filtoceb (fil VARCHAR, ceb VARCHAR)");
        //DELETE INITIALIZE SETUP START CLEAN
        eventsDB.delete("filtoceb", "1", null);
        eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Kumusta ka?','Kumusta ka?')");
        eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Maayo, salamat', 'Mabuti naman, salamat')");
        eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Unsay imong pangalan?',  'Ano pangalan mo?')");
        eventsDB.execSQL("INSERT INTO filtoceb (ceb, fil) VALUES ('Unsay ngalan mo?', 'ano pangalan mo?')");
        eventsDB.execSQL("INSERT INTO filtoceb (CEB, FIL) values ('Maayo nga nagka-ila ta', 'Ikinagagalak kitang makilala')");
        eventsDB.execSQL("INSERT INTO filtoceb (CEB, FIL) values ('Palihug','Please')");          

        eventsDB.close();

    } catch (Exception e) {
        e.printStackTrace();
    }