alliancekrot.blogg.se

1. HOW TO CREATE SQLITE DATABASE IN ANDROID STEP BY STEP UPDATE
2. HOW TO CREATE SQLITE DATABASE IN ANDROID STEP BY STEP CODE

HOW TO CREATE SQLITE DATABASE IN ANDROID STEP BY STEP CODE

The code of this constructor looks like this: public MyDBHandler(Context context, Stringname, The database can be initialized in the constructor of the MyDBHandler class.

We must also use import statements, as follows: import Type Student in the Name item, maintain the default options, and click the OK button:Īdding the following lines of code for the Student class: public class Student Right-click the myfirstdatabase package and selecting New > Java Class. We create the Student class in the Android Studio 3.0 by selecting app > java. The Student class contains fields, constructors, and properties as follows: My application model can be shown in the following figure: A third class (Student class) will need to be implemented to hold the database entry data as it is passed between the activity and the handler. The database handler will be a subclass of SQLiteOpenHelper and will provide an abstract layer between the underlying SQLite database and the activity class. The application will consist of an activity and a database handler class (MyDBHandler class). The Student table schema will look like this: My application will interact with a database named StudentDB.db, which contains a single table named Student.

We will create a database Android application that has a UI as follows: GetReadableDatabase(): creates or opens a database for reading only.ĬontentValues allows key/value pairs to be declared consisting of table column identifiers and the values to be stored in each column. GetWritableDatabase(): opens or creates a database for reading and writing. OnOpen(): called when the database is opened. OnUpgrade(): called in the event that the application code contains a more recent database version number reference. OnCreate(): called when the database is created for the first time.

HOW TO CREATE SQLITE DATABASE IN ANDROID STEP BY STEP UPDATE

SQLiteOpenHelper is designed to make it easier to create and update databases. RawQuery(): executes an SQL query statement and returns matching results in the form of a Cursor object. Query(): performs a specified database query and returns matching results via a Cursor object.ĮxecSQL(): executes a single SQL Statement that does not return result data. Insert(): inserts a new row into a database table.ĭelete(): deletes rows from a database table SQLiteDatabase provides the primary interface between the application code and underlying SQLite database. Get() (such as getInt(), getDouble(), so on): returns the value of the specified contained at the specified column index of the row at the current cursor position. Move(): moves by a specified offset from the current position in the result set. MoveToNext(): moves to the next row in the result set. MoveToLast(): moves to the last row in the result set. MoveToFirst(): moves to the first row in the result set. GetCount(): returns the number of rows contained within the result set. Its methods include:Ĭlose(): release all resources used by cursor and close it. Android SQLite Java ClassesĬursor: a class provides access to the results of a database query. Like other RDBMSs, data is accessed in a SQLite database by using Structured Query Language (SQL). are standalone server processes, then SQLite is embedded because it is provided in the form of a library that is linked in applications. If most RDBMSs such as MySQL, Oracle, etc. SQLite is a relational database management system (RDBMS).