我目前在Assets文件夹中有一个数据库。我有升级它的问题。每当我提出DATABASE_VERSION号码时，它只会更新某些时间。当它升级时，它会在开始时崩溃，我必须重新打开应用程序。
这是我的createDatabase（）
public void createDataBase() throws IOException {
boolean dbExist = checkdatabase();
if (dbExist) {
Log.v("DB Exists", "db exists");
// By calling this method here onUpgrade will be called on a
// writeable database, but only if the version number has been
// bumped
this.getWritableDatabase();
}
dbExist = checkdatabase();
if (!dbExist) {
// 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 {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
onUpgrade（）
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (newVersion > oldVersion){
Log.v("Database Upgrade", "Database version is higher than previous.");
myContext.deleteDatabase(DB_NAME);
}
我想删除我正在使用的旧数据库，只是让新数据库可用于应用程序布局。
将createDataBase()添加到onUpgrade()
03-06 15:17:15.348: V/DB Exists(2150): db exists
03-06 15:17:15.388: V/Database Upgrade(2150): Database version is higher than previous.
03-06 15:17:15.398: D/AndroidRuntime(2150): Shutting down VM
03-06 15:17:15.398: W/dalvikvm(2150): threadid=1: thread exiting with uncaught exception (group=0xb3f6d648)
03-06 15:17:15.418: E/AndroidRuntime(2150): FATAL EXCEPTION: main
03-06 15:17:15.418: E/AndroidRuntime(2150): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.productguide/com.example.productguide.PowersportsEquivalent}: java.lang.IllegalStateException: getDatabase called recursively
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.app.ActivityThread.access$600(ActivityThread.java:141)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.os.Handler.dispatchMessage(Handler.java:99)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.os.Looper.loop(Looper.java:137)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.app.ActivityThread.main(ActivityThread.java:5103)
03-06 15:17:15.418: E/AndroidRuntime(2150): at java.lang.reflect.Method.invokeNative(Native Method)
03-06 15:17:15.418: E/AndroidRuntime(2150): at java.lang.reflect.Method.invoke(Method.java:525)
03-06 15:17:15.418: E/AndroidRuntime(2150): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
03-06 15:17:15.418: E/AndroidRuntime(2150): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-06 15:17:15.418: E/AndroidRuntime(2150): at dalvik.system.NativeStart.main(Native Method)
03-06 15:17:15.418: E/AndroidRuntime(2150): Caused by: java.lang.IllegalStateException: getDatabase called recursively
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:204)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:188)
03-06 15:17:15.418: E/AndroidRuntime(2150): at com.example.productguide.DataBaseHelper.createDataBase(DataBaseHelper.java:143)
03-06 15:17:15.418: E/AndroidRuntime(2150): at com.example.productguide.DataBaseHelper.onUpgrade(DataBaseHelper.java:248)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:257)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:164)
03-06 15:17:15.418: E/AndroidRuntime(2150): at com.example.productguide.DataBaseHelper.createDataBase(DataBaseHelper.java:136)
03-06 15:17:15.418: E/AndroidRuntime(2150): at com.example.productguide.PowersportsEquivalent.onCreate(PowersportsEquivalent.java:57)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.app.Activity.performCreate(Activity.java:5133)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
03-06 15:17:15.418: E/AndroidRuntime(2150): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175)
03-06 15:17:15.418: E/AndroidRuntime(2150): ... 11 more
答案 0 :(得分：9)
浏览Google时，我找到了问题的答案。
将以下代码添加到我的copyDataBase()
SQLiteDatabase checkdb = null;
try{
String myPath = DB_PATH + DB_NAME;
checkdb = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
// Once the DB has been copied, set the new version
checkdb.setVersion(DATABASE_VERSION);
}
catch(SQLiteException e)
{
//database does’t exist yet.
}
并在onUpgrade()
if (oldVersion < newVersion){
Log.v("Test", "Within onUpgrade. Old is: " + oldVersion + " New is: " + newVersion);
myContext.deleteDatabase(DB_NAME);
try {
copyDataBase();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
我的数据库现在升级到数据库，并在DATABASE_VERSION整数的每次更改时删除之前的数据。
答案 1 :(得分：1)
java.lang.IllegalStateException: getDatabase called recursively
这是由于呼叫，例如来自getReadableDatabase()或getWritableDatabase()回调的onCreate()或onUpgrade()。回调被作为部分数据库打开过程调用，试图在那时再次打开它将是一个错误，除非SQLiteOpenHelper检测到并抛出此异常，否则可能导致无限递归。
进一步向下走栈：
at android.database.sqlite.SQLiteOpenHelper.getReadableDatabase(SQLiteOpenHelper.java:188)
at com.example.productguide.DataBaseHelper.createDataBase(DataBaseHelper.java:143)
at com.example.productguide.DataBaseHelper.onUpgrade(DataBaseHelper.java:248)
因此onUpgrade()调用createDataBase()来调用getReadableDatabase()。您发布的代码没有显示，它可能是其他版本的。
要使用经过测试和测试的帮助程序与预填充数据库一起使用，请考虑jgilfelt/sqlite-asset-helper。
答案 2 :(得分：0)
我认为我有一个更简单的解决方案，只需将其添加到您的DB Helper类：
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
super.setForcedUpgrade(newVersion);
super.onUpgrade(db, oldVersion, newVersion);
}
这会忽略之前存在的任何版本，并将其替换为您资产中的版本＆＃39;文件夹中。