无法使用SQLiteAssetHelper类复制数据库

Question

我正在扩展SQLiteAssetHelper类以使用我的资源文件夹中的预填充数据库,但我的应用程序崩溃并发出错误说Caused by: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database.

当我签入时ddms,没有数据库文件夹或我的db文件data/data/com.sqlitetospinner1/.因此,为了测试,我创建了一个名为的文件夹并将databasesdb文件推入其中.在此之后,应用程序开始完美运行.

这意味着我的AssetsHelper班级无法复制数据库.

AssetsHelper 类:-

public class AssetsHelper extends SQLiteAssetHelper {

private static final String DATABASE_NAME = "mydb.sqlite";
private static final int DATABASE_VERSION = 1;

public AssetsHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);

}


public List<String> getAllColleges(){
    List<String> colleges = new ArrayList<String>();

    // Select All Query
    String selectQuery = "SELECT * FROM colleges_list ORDER BY Organization_Name";

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);

    // looping through all rows and adding to list
    if (cursor.moveToFirst()) {
        do {
            colleges.add(cursor.getString(1));
        } while (cursor.moveToNext());
    }

    // closing connection
    cursor.close();
    db.close();

    // returning colleges
    return colleges;
}

LogCat:-

 08-25 08:41:21.927: W/SQLiteAssetHelper(27504): copying database from assets...
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504): Couldn't open mydb.sqlite for writing (will try read-only):
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504): com.readystatesoftware.sqliteasset.SQLiteAssetHelper$SQLiteAssetException: Missing databases/mydb.sqlite file (or .zip, .gz archive) in assets, or target folder not writable
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504):     at android.content.res.AssetManager.openAsset(Native Method)
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504):     at android.content.res.AssetManager.open(AssetManager.java:316)
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504):     at android.content.res.AssetManager.open(AssetManager.java:290)
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504):     at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.copyDatabaseFromAssets(SQLiteAssetHelper.java:436)
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504):     at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.createOrOpenDatabase(SQLiteAssetHelper.java:400)
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504):     at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.getWritableDatabase(SQLiteAssetHelper.java:176)
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504):     at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.getReadableDatabase(SQLiteAssetHelper.java:254)
    08-25 08:41:22.107: E/SQLiteAssetHelper(27504):     at com.crm.AssetsHelper.getAllColleges(AssetsHelper.java:38)
08-25 08:41:22.107: E/SQLiteAssetHelper(27504):     at dalvik.system.NativeStart.main(Native Method)
08-25 08:41:22.117: E/SQLiteLog(27504): (14) cannot open file at line 30191 of [00bb9c9ce4]
08-25 08:41:22.117: E/SQLiteLog(27504): (14) os_unix.c:30191: (2) open(/data/data/com.sqlitetospinner1/databases/mydb.sqlite) - 
08-25 08:41:22.167: E/SQLiteDatabase(27504): Failed to open database '/data/data/com.sqlitetospinner1/databases/mydb.sqlite'.
08-25 08:41:22.167: E/SQLiteDatabase(27504): android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database
08-25 08:41:22.167: E/SQLiteDatabase(27504):    at android.database.sqlite.SQLiteConnection.nativeOpen(Native Method)
08-25 08:41:22.167: E/SQLiteDatabase(27504):    at android.database.sqlite.SQLiteConnection.open(SQLiteConnection.java:209)
08-25 08:41:22.167: E/SQLiteDatabase(27504):    at com.crm.AssetsHelper.getAllColleges(AssetsHelper.java:38)

Answer 1

Missing databases/mydb.sqlite file (or .zip, .gz archive) in assets, or target folder not writable

你的文件assets/databases夹中有数据库文件吗？

不,仅在资产文件夹中

SQLiteAssetHelper期望在databases下面的文件夹中 找到预先填充的数据库文件assets.