What is cursor in android with example?

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 DB rawQuery?

Marks a method in a Dao annotated class as a raw query method where you can pass the query as a SupportSQLiteQuery . On the other hand, RawQuery serves as an escape hatch where you can build your own SQL query at runtime but still use Room to convert it into objects. RawQuery methods must return a non-void type.

What is the use of DB rawQuery () in SQLiteDatabase?

SQLiteDatabase.rawQuery() The open helper query method can construct an SQL query and send it as a rawQuery to the database which returns a cursor. If your data is supplied by your app, and under your full control, you can use rawQuery().

What is the function of rawQuery () in android?

Like the query() method, rawQuery() returns a cursor containing the result set for the query. The caller can read and process the resulting cursor in the same way that it processes the result from the query() methods.

How can I see my cursor on Android?

It’s pretty simple if you’re using Android 4.0 or later. Just go to Settings > Developer Options > Show Pointer location (or Show touches, whichever works) and toggle that on.

How do I change my cursor on my Android?

Large mouse pointer

  1. Settings → Accessibility → Large mouse pointer.
  2. (Samsung) Settings → Accessibility → Vision → Mouse pointer/touchpad pointer.
  3. (Xiaomi) Settings → Additional settings → Accessibility → Large mouse pointer.

What is DB execSQL?

1. 8. From the Android SDK documentation for SQLiteDatabase : execSQL(String sql): Execute a single SQL statement that is NOT a SELECT or any other SQL statement that returns data. In your example, to create the table, you would call db.

What is cursor moveToFirst?

“A Cursor object, which is positioned before the first entry.” Calling moveToFirst() does two things: it allows you to test whether the query returned an empty set (by testing the return value) and it moves the cursor to the first result (when the set is not empty).

What is the difference between query and rawQuery in android?

java in the android source shows that the query(..) ends up calling the QueryBuilder to build the query as a single string and then it essentially calls rawQuery(). They should be roughly equivalent, assuming that you also did the same work to build your own statement.

How do I enable my cursor on my phone?

How to make the mouse cursor larger

  1. To access the Accessibility features on your Android device open the Settings app.
  2. In the Settings app, select Accessibility from the list.
  3. On the Accessibility screen, scroll down to the Display section and select Large mouse cursor to set the toggle switch to On.

Why SQLite is used in Android?

SQLite is an open-source relational database i.e. used to perform database operations on android devices such as storing, manipulating or retrieving persistent data from the database. It is embedded in android bydefault. So, there is no need to perform any database setup or administration task.

What do you need to know about rawquery in Android?

RawQuery methods must return a non-void type. If you want to execute a raw query that does not return any value, use RoomDatabase#query methods. RawQuery methods can only be used for read queries. For write queries, use RoomDatabase.getOpenHelper ().getWritableDatabase () .

What are the parameters of the rawquery method?

The rawQuery method has two parameters: String query: The select statement String [] selection args: The arguments if a WHERE clause is included in the select statement Notes The result of a query is returned in Cursor object.

Which is a non observable query in rawquery?

Denotes the list of entities which are accessed in the provided query and should be observed for invalidation if the query is observable. The listed classes should either be annotated with Entity or they should reference to at least 1 Entity (via Embedded or Relation ). Providing this field in a non-observable query has no impact.

How to run rawquery in SQLite database?

RawQuery (String, String []) Runs the provided SQL and returns a ICursor over the result set.