android-sqlite – Page 3

How to import Room Persistence Library to an Android project

April 24, 2023 by Tarik

It’s possible to find the dependencies on the example codelab for the new architecture components. Root : allprojects { repositories { jcenter() maven { url “https://maven.google.com” } } For Room: implementation ‘android.arch.persistence.room:runtime:1.0.0-alpha1’ annotationProcessor ‘android.arch.persistence.room:compiler:1.0.0-alpha1’ For Lifecycle dependencies: implementation ‘android.arch.lifecycle:extensions:1.0.0-alpha1’ annotationProcessor ‘android.arch.lifecycle:compiler:1.0.0-alpha1’ Adding Rxjava2 objects as result for our queries: implementation ‘android.arch.persistence.room:rxjava2:1.0.0-alpha1′ Test migrations: testImplementation’android.arch.persistence.room:testing:1.0.0-alpha1’

Using String[] selectionArgs in SQLiteDatabase.query()

April 17, 2023 by Tarik

selectionArgs replace any question marks in the selection string. for example: String[] args = { “first string”, “second@string.com” }; Cursor cursor = db.query(“TABLE_NAME”, null, “name=? AND email=?”, args, null); as for your question – you can use null

Android Room compile-time warning about column in foreign key not part of an index. What does it mean?

April 6, 2023 by Tarik

When in kotlin code: Before @ColumnInfo(name = “question_id”) var questionId: Long After @ColumnInfo(name = “question_id”, index = true) //just add index = true var questionId: Long

Android SQLiteOpenHelper: Why onCreate() method is not called?

March 29, 2023 by Tarik

I have also had trouble with the SQLiteOpenHelper. What worked for me was storing a member variable SQLiteDatabase db; In the SQLiteOpenHelper subclass and calling db = getWritableDatabase(); in the constructor. The answer to this question also includes helpful information: SQLiteOpenHelper failing to call onCreate? I hope this helps!

Database won’t remove when uninstall the Android Application

March 25, 2023 by Tarik

in Android 6.0, google added new feature called Auto Backup. when this option is on(default is on), Android system copies almost every directories and files that created by system, and upload it to user’s google drive account. When user reinstalls app, android automatically restore app’s data, no matter how it was installed(via Play store, adb … Read more

Android SQLite Insert or Update

March 6, 2023 by Tarik

I believe that you are asking how to INSERT new rows or UPDATE your existing rows in one step. While that is possible in a single raw SQL as discussed in this answer, I found that it easier to do this in two steps in Android using SQLiteDatabase.insertWithOnConflict() using CONFLICT_IGNORE for conflictAlgorithm. ContentValues initialValues = … Read more

How to get row count in sqlite using Android?

March 6, 2023 by Tarik

Using DatabaseUtils.queryNumEntries(): public long getProfilesCount() { SQLiteDatabase db = this.getReadableDatabase(); long count = DatabaseUtils.queryNumEntries(db, TABLE_NAME); db.close(); return count; } or (more inefficiently) public int getProfilesCount() { String countQuery = “SELECT * FROM ” + TABLE_NAME; SQLiteDatabase db = this.getReadableDatabase(); Cursor cursor = db.rawQuery(countQuery, null); int count = cursor.getCount(); cursor.close(); return count; } In Activity: int … Read more

How to perform an SQLite query within an Android application?

February 27, 2023 by Tarik

This will return you the required cursor Cursor cursor = db.query(TABLE_NAME, new String[] {“_id”, “title”, “title_raw”}, “title_raw like ” + “‘%Smith%'”, null, null, null, null);

android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database

February 18, 2023 by Tarik

Add this permission to your project’s AndroidManifest.xml file, in the manifest tag (which should be the top level tag). <uses-permission android:name=”android.permission.WRITE_EXTERNAL_STORAGE” />

How to use Room Persistence Library with pre-populated database?

February 14, 2023 by Tarik

This is how I solved it, and how you can ship your application with a pre-populated database (up to Room v. alpha5) put your SQLite DB database_name.db into the assets/databases folder take the files from this repo and put them in a package called i.e. sqlAsset in your AppDatabase class, modify your Room’s DB creation … Read more