Índice de contenidos
What is nullColumnHack in android?
Android SQLite: nullColumnHack parameter in insert/replace methods (1 answer) Closed 5 years ago. According to the SQLiteDatabase API documentation: insert(String table, String nullColumnHack, ContentValues values) Convenience method for inserting a row into the database.
What is null column hack?
SQL doesn’t allow inserting a completely empty row without naming at least one column name. … If not set to null, the nullColumnHack parameter provides the name of nullable column name to explicitly insert a NULL into in the case where your values is empty.
What is difference between ContentValues and cursor?
Q 12 – What is the difference between content values and cursor in android SQlite? A – Content values are key pair values, which are updated or inserted in the database B – Cursor is used to store the temporary result. C – A & B D – Cursor is used to store data permanently.
What is Android getWritableDatabase?
getWritableDatabase() Create and/or open a database that will be used for reading and writing. void. onConfigure(SQLiteDatabase db) Called when the database connection is being configured, to enable features such as write-ahead logging or foreign key support.
What is the use of Cursor in Android?
A Cursor represents the result of a query and basically points to one row of the query result. This way Android can buffer the query results efficiently; as it does not have to load all data into memory. To get the number of elements of the resulting query use the getCount() method.
What is ContentValues?
ContentValues is a maplike class that matches a value to a String key. It contains multiple overloaded put methods that enforce type safety. Here is a list of the put methods supported by ContentValues: void put(String key, Byte value) void put(String key, Integer value)
What is the application class in Android?
The Application class in Android is the base class within an Android app that contains all other components such as activities and services. The Application class, or any subclass of the Application class, is instantiated before any other class when the process for your application/package is created.
What is SQLiteOpenHelper class in Android?
android.database.sqlite.SQLiteOpenHelper. A helper class to manage database creation and version management. You create a subclass implementing onCreate , onUpgrade and optionally onOpen , and this class takes care of opening the database if it exists, creating it if it does not, and upgrading it as necessary.
What are interfaces in Android?
The user interface (UI) for an Android app is built as a hierarchy of layouts and widgets. The layouts are ViewGroup objects, containers that control how their child views are positioned on the screen. Widgets are View objects, UI components such as buttons and text boxes.
How do I find location on Android?
Help your phone get a more accurate location (Google Location Services a.k.a. Google Location Accuracy)
- Swipe down from the top of the screen.
- Touch and hold Location . If you don’t find Location , tap Edit or Settings . …
- Tap Advanced. Google Location Accuracy.
- Turn Improve Location Accuracy on or off.
