Database update without data loss. FATAL EXCEPTION: ModernAsyncTask #1 - android-sqlite

Question

I need to implement an update of the database lying in the assets. User data, namely, in the "favorite" record or not, should be saved.
I already asked a question and they helped me -https://stackoverflow.com/a/53827525/10261947
Everything worked in a test application. But when I transferred the code (exactly the same) to the real application, an error occurs - E/AndroidRuntime: FATAL EXCEPTION: ModernAsyncTask #1
Process: rodionova.lyubov.brodsky, PID: 4196
java.lang.RuntimeException: An error occurred while executing doInBackground()
at android.support.v4.content.ModernAsyncTask$3.done(ModernAsyncTask.java:161)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:383)
at java.util.concurrent.FutureTask.setException(FutureTask.java:252)
at java.util.concurrent.FutureTask.run(FutureTask.java:271)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:784)
Caused by: java.lang.IllegalArgumentException: the bind value at index 4 is null
at android.database.sqlite.SQLiteProgram.bindString(SQLiteProgram.java:169)
at android.database.sqlite.SQLiteProgram.bindAllArgsAsStrings(SQLiteProgram.java:205)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:47)
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1397)
at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1239)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1110)
at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1278)
at rodionova.lyubov.brodsky.db.PoemsDbHelper.insertCorePoem(PoemsDbHelper.java:121)
at rodionova.lyubov.brodsky.db.PoemsDbHelper.getNewPoems(PoemsDbHelper.java:90)
at rodionova.lyubov.brodsky.db.PoemsDbHelper.onUpgrade(PoemsDbHelper.java:41)
at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.getWritableDatabase(SQLiteAssetHelper.java:197)
at com.readystatesoftware.sqliteasset.SQLiteAssetHelper.getReadableDatabase(SQLiteAssetHelper.java:254)
at rodionova.lyubov.brodsky.db.PoemsProvider.query(PoemsProvider.java:45)
at android.content.ContentProvider.query(ContentProvider.java:1057)
If you do not perform the update, the application is working properly, so I will post only the code DbHelper
public class PoemsDbHelper extends SQLiteAssetHelper {
public static final String DB_NAME = "brodsky.db";
public static final int DBVERSION = 3;
public static final String TBLNAME = "poems_table";
public static final String COL_ID = "id";
public static final String COL_TITLE = "title";
public static final String COl_POEM = "poem";
public static final String COL_SUBJECT = "subject";
public static final String COL_YEARS = "years";
public static final String COL_FAVOURITE = "favorite";
Context mContext;
public PoemsDbHelper(Context context) {
super(context, DB_NAME, null, DBVERSION);
mContext = context;
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if(newVersion > oldVersion)
getNewPoems(mContext, db);
}
private void getNewPoems(Context context, SQLiteDatabase db) {
InputStream is;
OutputStream os;
final String tempNewDbName = "temp_brodsky.db";
int buffersize = 4096;
byte[] buffer = new byte[buffersize];
String newDBPath = mContext.getDatabasePath(tempNewDbName).getPath();
File newDBFile = new File(newDBPath);
if (newDBFile.exists()) {
newDBFile.delete();
}
File newDBFileDirectory = newDBFile.getParentFile();
if (!newDBFileDirectory.exists()) {
newDBFileDirectory.mkdirs();
}
try {
is = context.getAssets().open("databases/" + DB_NAME);
os = new FileOutputStream(newDBFile);
int bytes_read;
while ((bytes_read = is.read(buffer,0,buffersize)) > 0) {
os.write(buffer);
}
os.flush();
os.close();
is.close();
}catch (IOException e) {
e.printStackTrace();
throw new RuntimeException("Ouch updated database not copied - processing stopped - see stack-trace above.");
}
long id = maxid(db) + 1;
SQLiteDatabase newdb = SQLiteDatabase.openDatabase(newDBFile.getPath(),null,SQLiteDatabase.OPEN_READONLY);
Cursor csr = newdb.query(TBLNAME,null,null,null,null,null,null);
long insert_result;
db.beginTransaction();
while (csr.moveToNext()) {
insert_result = insertCorePoem(
db,
id,
csr.getString(csr.getColumnIndex(COL_TITLE)),
csr.getString(csr.getColumnIndex(COl_POEM)),
csr.getString(csr.getColumnIndex(COL_SUBJECT)),
csr.getString(csr.getColumnIndex(COL_YEARS)),
csr.getString(csr.getColumnIndex(COL_FAVOURITE))
);
if (insert_result > 0) {
id++;
}
}
db.setTransactionSuccessful();
db.endTransaction();
csr.close();
newDBFile.delete();
}
public long insertCorePoem(SQLiteDatabase db, long id, String title, String poem, String subject, String years, String favourite) {
String whereclause = COL_TITLE + "=? AND " + COl_POEM + "=? AND " + COL_SUBJECT + "=? AND " + COL_YEARS + "=?";
String[] whereargs = new String[]{
title,
poem,
subject,
years
};
Cursor csr = db.query(TBLNAME,null,whereclause,whereargs,null,null,null);
boolean rowexists = (csr.getCount() > 0);
csr.close();
if (rowexists) {
Log.d("INSERTCOREPOEM","Skipping insert of row");
return -2;
}
ContentValues cv = new ContentValues();
cv.put(COL_ID,id);
cv.put(COL_TITLE,title);
cv.put(COl_POEM,poem);
cv.put(COL_SUBJECT,subject);
cv.put(COL_YEARS,years);
cv.put(COL_FAVOURITE,favourite);
Log.d("INSERTCOREPOEM","Inserting new column with id " + String.valueOf(id));
return db.insert(TBLNAME, null, cv);
}
private long maxid(SQLiteDatabase db) {
long rv = 0;
String extractcolumn = "maxid";
String[] col = new String[]{"max(" + COL_ID + ") AS " + extractcolumn};
Cursor csr = db.query(TBLNAME,col,null,null,null,null,null);
if (csr.moveToFirst()) {
rv = csr.getLong(csr.getColumnIndex(extractcolumn));
}
csr.close();
return rv;
}
}
I do not understand what is wrong. Identical code works great friend application. I would be grateful for the help.

Answer 1

Your issue is that you likely have a value of null in the years column of a row or rows in the updated database that data is being copied from.
Although you could change the code to handle (skip insertion or use provide a year value) the end result may not be desired. So the most likely fix would be to amend the database to have valid/useful year values.