Android 应用程序在开始使用 SQLite 数据库时启动后立即崩溃

Question

我创建了一个应用程序来测试如何在Android应用程序中实现SQLite数据库。但是该应用程序甚至没有启动，我不知道是什么导致了麻烦。 这是我的代码：

日志猫：

public class MainActivity extends AppCompatActivity {
EditText buckysInput;
TextView buckysText;
MyDBHandbler dbHandbler;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
buckysInput = (EditText) findViewById(R.id.buckysInput);
buckysText = (TextView) findViewById(R.id.buckysText);
dbHandbler = new MyDBHandbler(this, null, null, 1);
printDatabase();
}
public void addButtonClicked(View view){
Products products = new Products(buckysInput.getText().toString());
dbHandbler.addProduct(products);
printDatabase();
}
public  void deleteButtonClicked(View view){
String input = buckysInput.getText().toString();
dbHandbler.deletProduct(input);
printDatabase();
}

public void printDatabase() {
String dbString = dbHandbler.databaseToString();
buckysText.setText(dbString);
buckysInput.setText("");
}
}

My SQLiteOpenHelperClass：

public class MyDBHandbler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "products.db";
public static final String TABLE_PRODUCTS="products";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_PRODUCTNAME = "productname";
public MyDBHandbler(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, DATABASE_NAME, factory, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
String query = "CREATE TABLE " + TABLE_PRODUCTS + "(" +
COLUMN_ID + "INTEGER PRIMARY KEY AUTOINCREMENT" +
COLUMN_PRODUCTNAME + "TEXT" +
");";
db.execSQL(query);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS" + TABLE_PRODUCTS);
onCreate(db);
}
//Add a new row to the database
public void addProduct(Products products){
ContentValues values = new ContentValues();
values.put(COLUMN_PRODUCTNAME, products.get_productname());
SQLiteDatabase db = getWritableDatabase();
db.insert(TABLE_PRODUCTS, null, values);
db.close();
}
//Delet Product from the database
public void deletProduct(String productName){
SQLiteDatabase db = getWritableDatabase();
db.execSQL("DELET FROM" + TABLE_PRODUCTS + "WHERE" + COLUMN_PRODUCTNAME  +"="" + productName + "";");
}
//Print out the databse as a String
public String databaseToString(){
String dbString ="";
SQLiteDatabase db = getWritableDatabase();
String query = "SELECT * FROM" + TABLE_PRODUCTS +"WHERE 1";
//Cursor point to a location in your results
Cursor c = db.rawQuery(query, null);
c.moveToFirst();
while(!c.isAfterLast()){
if(c.getString(c.getColumnIndex("productname"))!= null){
dbString += c.getString(c.getColumnIndex("productname"));
dbString += "n";
}
}
db.close();
return dbString;
}
}

产品类别：

package com.example.phili.sqlitesmaple;
/**
* Created by phili on 29.07.2017.
*/
public class Products {
private int _id;
private String _productname;
public  Products(){
}
public Products(String _productname){
this._productname = _productname;
}
public void set_id(int _id){
this._id = _id;
}
public void set_productname(String _productname){
this._productname = _productname;
}
public int get_id() {
return _id;
}
public String get_productname() {
return _productname;
}
}

安卓清单：

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.phili.sqlitesmaple">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<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>

Logcat
:23838-23838/? I/art: Late-enabling -Xcheck:jni
23838-23852/com.example.phili.sqlitesmaple E/HAL: load: id=gralloc != hmi->id=gralloc
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_dependencies_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_0_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_1_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_2_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
[ 07-29 20:26:08.842  3724: 3724 E/         ]
process stopped due to unexpected signal 13
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_3_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_4_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_5_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_6_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_7_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_8_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/art: Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg  --debuggable --instruction-set=arm --instruction-set-features=smp,div,atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a15 --instruction-set-features=default --dex-file=/data/app/com.example.phili.sqlitesmaple-1/split_lib_slice_9_apk.apk --oat-file=/data/dalvik-cache/arm/data@[e-mail]-1@[e-mail]) because non-0 exit status
23838-23838/com.example.phili.sqlitesmaple W/System: ClassLoader referenced unknown path: /data/app/com.example.phili.sqlitesmaple-1/lib/arm
23838-23838/com.example.phili.sqlitesmaple I/InstantRun: starting instant run server: is main process
23838-23838/com.example.phili.sqlitesmaple I/HwCust: Constructor found for class android.app.HwCustHwWallpaperManagerImpl
23838-23838/com.example.phili.sqlitesmaple W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
23838-23838/com.example.phili.sqlitesmaple E/SQLiteLog: (1) 
23838-23838/com.example.phili.sqlitesmaple I/Process: Sending signal. PID: 23838 SIG: 9

我认为这一定是SQLite数据库的问题，因为没有它就可以正常工作。 我希望你能帮助我。来自德国的问候。

Answer 1

要明确修复的一件事是onCreate SQL语句中的空格。使用字符串连接时，SQL 语句无效：

String query = "CREATE TABLE " + TABLE_PRODUCTS + "(" +
COLUMN_ID + "INTEGER PRIMARY KEY AUTOINCREMENT" +
COLUMN_PRODUCTNAME + "TEXT" +
");";

会决心...

CREATE TABLE products(_idINTEGER PRIMARY KEY AUTOINCREMENTproductnameTEXT);

在所有 SQL 语句中也是如此，包括删除和选择。

Answer 2

不使用 printDatabase((; 因为第一次你的数据库没有值，它很可能会返回 null，所以不要在OnCreate上使用此方法

首先，您的插入查询是错误的，没有空格和逗号

您的查询

String query = "CREATE TABLE " + TABLE_PRODUCTS + "(" +
COLUMN_ID + "INTEGER PRIMARY KEY AUTOINCREMENT" +
COLUMN_PRODUCTNAME + "TEXT" +
");";

结果没有空格，也缺少逗号

CREATE TABLE products(_idINTEGER PRIMARY KEY AUTOINCREMENTproductnameTEXT);

修改后的查询

String query = "CREATE TABLE " + TABLE_PRODUCTS + "(" +
COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT"+", " +
COLUMN_PRODUCTNAME + " TEXT" +
");";

结果

CREATE TABLE products(_id INTEGER PRIMARY KEY AUTOINCREMENT, productname TEXT);

第二个在你的数据库到字符串方法中，你的查询在下面使用错误

// type e.g id , productname
String query = "SELECT * FROM " + TABLE_PRODUCTS +" WHERE type = 1";