Android SQLite Database Tutorial216

A database is an organized collection of data. It can be used to store information such as customer data, product data, or order data. SQLite is a lightweight database that is embedded in Android devices. It is a popular choice for developing Android applications because it is easy to use and does not require a separate server.

Getting Started

To use SQLite in your Android application, you need to add the following permissions to your manifest file:```xml

```

Next, you need to create a database object. You can do this by calling the openOrCreateDatabase() method of the SQLiteDatabase class. The openOrCreateDatabase() method takes two parameters: the name of the database and the mode in which to open the database.```java
SQLiteDatabase db = openOrCreateDatabase("myDatabase", MODE_PRIVATE);
```

The MODE_PRIVATE parameter specifies that the database is only accessible to the application that created it. You can also use the MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE parameters to make the database accessible to other applications.

Creating a Table

Once you have a database object, you can create a table using the createTable() method. The createTable() method takes two parameters: the name of the table and a CREATE TABLE statement.```java
("myTable", "CREATE TABLE myTable (id INTEGER PRIMARY KEY, name TEXT, age INTEGER)");
```

The CREATE TABLE statement specifies the name of the table and the columns that it contains. The id column is the primary key of the table. The name and age columns are regular columns.

Inserting Data

To insert data into a table, you can use the insert() method of the SQLiteDatabase class. The insert() method takes three parameters: the name of the table, a set of values to insert, and a conflict resolution policy.```java
ContentValues values = new ContentValues();
("name", "John Doe");
("age", 30);
("myTable", null, values);
```

The ContentValues object contains the values to insert into the table. The null parameter specifies that the id column should be auto-generated. You can also specify a conflict resolution policy using the conflictAlgorithm parameter.

Updating Data

To update data in a table, you can use the update() method of the SQLiteDatabase class. The update() method takes four parameters: the name of the table, a set of values to update, a where clause, and a where clause argument.```java
ContentValues values = new ContentValues();
("name", "Jane Doe");
("myTable", values, "id = ?", new String[] { "1" });
```

The ContentValues object contains the values to update in the table. The "id = ?" where clause specifies that only the row with the id of 1 should be updated. The new String[] { "1" } where clause argument specifies the value of the id column for the row that should be updated.

Deleting Data

To delete data from a table, you can use the delete() method of the SQLiteDatabase class. The delete() method takes three parameters: the name of the table, a where clause, and a where clause argument.```java
("myTable", "id = ?", new String[] { "1" });
```

The "id = ?" where clause specifies that only the row with the id of 1 should be deleted. The new String[] { "1" } where clause argument specifies the value of the id column for the row that should be deleted.

Closing the Database

Once you have finished using a database, you should always close it by calling the close() method of the SQLiteDatabase class. Failing to close a database can lead to memory leaks```java
();
```

2024-11-29

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