Query sqlite database android4/27/2024 ![]() ![]() getCount() returns the number of rows in the cursor.MatrixCursor is an all-rounder, a mutable cursor implementation backed by an array of objects that automatically expands internal capacity as needed.SQLiteCursor is not internally synchronized, so code using a SQLiteCursor from multiple threads should perform its own synchronization when using the SQLiteCursor. SQLiteCursor exposes results from a query on a SQLiteDatabase.The Cursor class has a number of subclasses that implement cursors for specific types of data. The Cursor class provides methods for moving the cursor through the data structure, and methods to get the data from the fields in each row. A cursor is a pointer into one row of that structured data. You can think of the data as an array of rows. The SQLiteDatabase always presents the results as a Cursor in a table format that resembles that of a SQL database. There are two data types associated with using SQLite databases in particular, Cursor and ContentValues. Your app should only interact with the SQLiteOpenHelper, which will be described below. When you use an SQLite database, represented as an SQLiteDatabase object, all interactions with the database are through an instance of the SQLiteOpenHelper class which executes your requests and manages your database for you. Content providers, which will be introduced in a later chapter, work excellently with SQLite databases.If you can represent your data as rows and columns, consider a SQLite database.You can use the database as the primary storage for user or app data, or you can use it to cache and make available data fetched from the cloud.An SQLite database is a good storage solution when you have structured data that you need to store persistently and access, search, and change frequently.Of the many storage options discussed, using a SQLite database is one of the most versatile, and straightforward to implement. Check out the SQL Primer chapter if you need a refresher. It is not an introduction to SQLite or SQL databases.The chapter assumes that you are familiar with SQL databases in general, and basic SQL query building. This chapter discusses the Android framework's SQLiteDatabase and SQLiteOpenHelper classes. This course is now deprecated and this content will be The new course is available atĪndroid Developer Fundamentals course (Version 2), or go directly to ![]() Lesson 13: Permissions, Performance and Securityġ3.1: Permissions, Performance and SecurityĪ new version of this course is now available, updated to reflectīest practices for more recent versions of the Android framework andĪndroid Studio. Lesson 11: Sharing data with content providersġ1.1: Share Data Through Content Providers Lesson 8: Triggering, scheduling and optimizing background tasks Lesson 3: Testing, debugging, and using support librariesĥ.3: Providing Resources for Adaptive Layouts 2.1: Understanding Activities and IntentsĢ.2: The Activity Lifecycle and Managing State ![]()
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