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Android SQLite:

  • 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 by default. So, there is no need to perform any database setup or administration task.
  • Here, we are going to see the example of sqlite to store and fetch the data.
  • Data is displayed in the logcat. For displaying data on the spinner or listview, move to the next page.
  • SQLiteOpenHelper class provides the functionality to use the SQLite database.
 android sqlite database

SQLiteOpenHelper class:

  • The android.database.sqlite.SQLiteOpenHelper class is used for database creation and version management.
  • For performing any database operation, you have to provide the implementation of onCreate() and onUpgrade() methods of SQLiteOpenHelper class.
 process of sqlite

Android Sqlite Example:

  • In this example, we are adding a label on button click and displaying all the added labels on the spinner.
  • As you have seen in the previous example, SQLiteOpenHelper class need to be extended for performing operations on the sqlite.
  • We have overridden the onCreate() and onUpgrade() method of SQLiteOpenHelper class in the DatabaseHandler class that provides additional methods to insert and display the labels or data.

Android Sqlite Spinner Example:

  • Let's see the simple code to add and display the string content on spinner using sqlite database.
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activity_main.xml

  • File: activity_main.xml
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<RelativeLayout xmlns:androclass="http://schemas.android.com/apk/res/android"  
    xmlns:tools="http://schemas.android.com/tools"  
    android:layout_width="match_parent"  
    android:layout_height="match_parent"  
    tools:context=".MainActivity" >  
  
     <!-- Label -->  
    <TextView  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:text="Add New Label"  
        android:padding="8dip" />  
  
    <!-- Input Text -->  
    <EditText android:id="@+id/input_label"  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:layout_marginLeft="8dip"  
        android:layout_marginRight="8dip"/>  
  
    <Spinner  
        android:id="@+id/spinner"  
        android:layout_width="fill_parent"  
        android:layout_height="wrap_content"  
        android:layout_alignParentLeft="true"  
        android:layout_below="@+id/btn_add"  
        android:layout_marginTop="23dp" />  
  
    <Button  
        android:id="@+id/btn_add"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_below="@+id/input_label"  
        android:layout_centerHorizontal="true"  
        android:text="Add Item" />  
     
</RelativeLayout>  
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Activity class

  • File: MainActivity.java
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package com.example.sqlitespinner;  
  
import android.os.Bundle;  
import android.app.Activity;  
import android.view.Menu;  
import java.util.List;  
import android.content.Context;  
import android.view.View;  
import android.view.inputmethod.InputMethodManager;  
import android.widget.AdapterView;  
import android.widget.AdapterView.OnItemSelectedListener;  
import android.widget.ArrayAdapter;  
import android.widget.Button;  
import android.widget.EditText;  
import android.widget.Spinner;  
import android.widget.Toast;  
  
public class MainActivity extends Activity implements OnItemSelectedListener{  
    Spinner spinner;  
    Button btnAdd;  
    EditText inputLabel;  
   
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
   
        spinner = (Spinner) findViewById(R.id.spinner);  
        btnAdd = (Button) findViewById(R.id.btn_add);  
        inputLabel = (EditText) findViewById(R.id.input_label);  
   
        spinner.setOnItemSelectedListener(this);  
   
        // Loading spinner data from database  
        loadSpinnerData();  
   
        btnAdd.setOnClickListener(new View.OnClickListener() {  
   
            @Override  
            public void onClick(View arg0) {  
                String label = inputLabel.getText().toString();  
   
                if (label.trim().length() > 0) {  
                    DatabaseHandler db = new DatabaseHandler(getApplicationContext());  
                    db.insertLabel(label);  
   
                    // making input filed text to blank  
                    inputLabel.setText("");  
   
                    // Hiding the keyboard  
                    InputMethodManager imm = (InputMethodManager)   
                          getSystemService(Context.INPUT_METHOD_SERVICE);  
                    imm.hideSoftInputFromWindow(inputLabel.getWindowToken(), 0);  
   
                    // loading spinner with newly added data  
                    loadSpinnerData();  
                } else {  
                    Toast.makeText(getApplicationContext(), "Please enter label name",  
                            Toast.LENGTH_SHORT).show();  
                }  
   
            }  
        });  
    }  
   
    /** 
     * Function to load the spinner data from SQLite database 
     * */  
    private void loadSpinnerData() {  
        DatabaseHandler db = new DatabaseHandler(getApplicationContext());  
        List<String> labels = db.getAllLabels();  
   
        // Creating adapter for spinner  
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item, labels);  
   
        // Drop down layout style - list view with radio button  
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);  
   
        // attaching data adapter to spinner  
        spinner.setAdapter(dataAdapter);  
    }  
   
    @Override  
    public void onItemSelected(AdapterView<?> parent, View view, int position,  
            long id) {  
        // On selecting a spinner item  
        String label = parent.getItemAtPosition(position).toString();  
   
        // Showing selected spinner item  
        Toast.makeText(parent.getContext(), "You selected: " + label,  
                Toast.LENGTH_LONG).show();  
   
    }  
   
    @Override  
    public void onNothingSelected(AdapterView<?> arg0) {  
        // TODO Auto-generated method stub  
   
    }  
    @Override  
    public boolean onCreateOptionsMenu(Menu menu) {  
        // Inflate the menu; this adds items to the action bar if it is present.  
        getMenuInflater().inflate(R.menu.activity_main, menu);  
        return true;  
    }  
  
}  
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DatabaseHandler class

  • File: DatabaseHandler.java
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package com.example.sqlitespinner2;  
import java.util.ArrayList;  
import java.util.List;  
import android.content.ContentValues;  
import android.content.Context;  
import android.database.Cursor;  
import android.database.sqlite.SQLiteDatabase;  
import android.database.sqlite.SQLiteOpenHelper;  

public class DatabaseHandler extends SQLiteOpenHelper {  
private static final int DATABASE_VERSION = 1;  
private static final String DATABASE_NAME = "spinnerExample";  
private static final String TABLE_NAME = "labels";  
private static final String COLUMN_ID = "id";  
private static final String COLUMN_NAME = "name";  

public DatabaseHandler(Context context) {  
super(context, DATABASE_NAME, null, DATABASE_VERSION);  
}  

// Creating Tables  
@Override  
public void onCreate(SQLiteDatabase db) {  
// Category table create query  
String CREATE_ITEM_TABLE = "CREATE TABLE " + TABLE_NAME + "("  
+ COLUMN_ID + " INTEGER PRIMARY KEY," + COLUMN_NAME + " TEXT)";  
db.execSQL(CREATE_ITEM_TABLE);  
}  

// Upgrading database  
@Override  
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {  
// Drop older table if existed  
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);  

// Create tables again  
onCreate(db);  
}  

/** 
Inserting new lable into lables table 
*/  
public void insertLabel(String label){  
SQLiteDatabase db = this.getWritableDatabase();  

ContentValues values = new ContentValues();  
values.put(COLUMN_NAME, label);//column name, column value  

// Inserting Row  
db.insert(TABLE_NAME, null, values);//tableName, nullColumnHack, CotentValues  
db.close(); // Closing database connection  
}  

/** 
Getting all labels 
returns list of labels 
*/  
public List<String> getAllLabels(){  
List<String> list = new ArrayList<String>();  

// Select All Query  
String selectQuery = "SELECT  * FROM " + TABLE_NAME;  

SQLiteDatabase db = this.getReadableDatabase();  
Cursor cursor = db.rawQuery(selectQuery, null);//selectQuery,selectedArguments  

// looping through all rows and adding to list  
if (cursor.moveToFirst()) {  
do {  
list.add(cursor.getString(1));//adding 2nd column data  
} while (cursor.moveToNext());  
}  
// closing connection  
cursor.close();  
db.close();  

// returning lables  
return list;  
}  
}  
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Output:

 sqlite process
 sqlite spinner process
 view of sqlite

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