A simple Android SQLite template to use databases. The example table holds information about users and their corresponding password. (It's only an example to show the usage so the passwords aren't encrypted by the sample code.)

AbstractDb.java

package de.databasetemplate.db;

import java.util.HashMap;
import java.util.Map;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.util.Log;

/**
 * This class provides basic functionality to use a database table.
 * 
 * @author Andreas Bender
 */
public abstract class AbstractDb {

	public static final String COL_ID     = "_id";
	
	protected SQLiteHelper dbHelper;
	protected SQLiteDatabase database;
	
	public AbstractDb(Context context) {
		this.dbHelper = new SQLiteHelper(context);
	}
	
	public void open() {
		database = dbHelper.getWritableDatabase();
	}
	
	public void close() {
		dbHelper.close();
	}
	
	/**
	 * Create a new entry.
	 * 
	 * @param values A HashMap containing Column - Value pairs.
	 *  new HashMap<String, Object>().put(COL_IP4, "127.0.0.1");
	 * @return The ID of the newly created entry or -1 if an error occured.
	 */
	public long create(HashMap<String, ?> values) {
		
		ContentValues storeValues = new ContentValues();

		for(Map.Entry<String, ?> entry : values.entrySet()) {
			String column = entry.getKey();
			if(isStringColumn(column)) {
				storeValues.put(column, (String) entry.getValue());
			} else if(isIntegerColumn(column)) {
				storeValues.put(column, (Integer) entry.getValue());
			} else {
				Log.w(getLogTag(), IdentitiesDb.class.getName() + 
						"- create: Trying to insert an unknown column type! " +
						"(Column: " + column + ")");
			}
		}
		
		return database.insert(getTableName(), null, storeValues);
	}
	
	public void delete(long id) {
		database.delete(getTableName(), COL_ID + " = " + id, null);
	}
	
	/**
	 * Update an existing entry.
	 * 
	 * @param id The id identifying the entry.
	 * @param values A HashMap containing Column - Value pairs.
	 *  new HashMap<String, Object>().put(COL_IP4, "127.0.0.1");
	 * @return True if any row has been changed. False otherwise.
	 */
	public boolean update(long id, HashMap<String, ?> values) {
		ContentValues storeValues = new ContentValues();
		
		for(Map.Entry<String, ?> entry : values.entrySet()) {
			String column = entry.getKey();
			if(isStringColumn(column)) {
				storeValues.put(column, (String) entry.getValue());
			} else if(isIntegerColumn(column)) {
				storeValues.put(column, (Integer) entry.getValue());
			} else if(isBlobColumn(column)) {
				storeValues.put(column, (byte[]) entry.getValue());
			} else {
				Log.w(getLogTag(), IdentitiesDb.class.getName() + 
						"- update: Trying to update an unknown column type! " +
						"(Column: " + column + ")");
			}
		}
		return database.update(getTableName(), storeValues, COL_ID+" = "+id, null) > 0;
	}
	
	/**
	 * Find an item based on its ID.
	 * 
	 * @param id The ID of the required item.
	 * @return A Cursor pointing to the required item or null if it's not present.
	 */
	public Cursor get(long id) {
		
        Cursor cursor = database.query(true, getTableName(), getColumns(),
                        COL_ID + "=" + id, null, null, null, null, null);
		if (cursor != null) {
			cursor.moveToFirst();
		}
        return cursor;
		
	}
	
	/**
	 * Find all items of the table.
	 * 
	 * @return A Cursor pointing to the first item of the table.
	 */
    public Cursor all() {
    	return database.query(getTableName(), getColumns(), null, null, null, null, null);
    }
    
    public boolean isEmpty() {
    	return (all().getCount() == 0);
    }
    
    /**
     * @return All columns of the table, including the ID-column.
     */
    protected abstract String[] getColumns();
    
    /**
     * @return The name of the table.
     */
    protected abstract String getTableName();
    
    /**
     * @return The log tag used by LogCat, something like "MY_APP - DB"
     */
    protected abstract String getLogTag();
    
    /**
     * @param c The column which needs to be evaluated.
     * @return True if the column stores Strings, false otherwise.
     */
    protected abstract boolean isStringColumn(String c);

    /**
     * @param c The column which needs to be evaluated.
     * @return True if the column stores Integers, false otherwise.
     */
    protected abstract boolean isIntegerColumn(String c);
    
    /**
     * @param c The column which needs to be evaluated.
     * @return True if the column stores Blobs, false otherwise.
     */
    protected abstract boolean isBlobColumn(String c);
	
}

IdentitiesDb.java

package de.databasetemplate.db;

import android.content.ContentValues;
import android.content.Context;

public class IdentitiesDb extends AbstractDb{

	public static final String TABLE_NAME = "identities";
	public static final String COL_USER   = "user";
	public static final String COL_PW     = "pw";
	
	public static final String[] COLUMNS = {
		COL_ID, COL_USER, COL_PW
	};
	
	public IdentitiesDb(Context context) {
		super(context);
	}
	
	protected String[] getColumns() {
		return COLUMNS;
	}
	
	protected String getTableName() {
		return TABLE_NAME;
	}
	
	protected String getLogTag() {
		return "MY_APP";
	}
	
    protected boolean isStringColumn(String c) {
    	return (c == COL_USER || c == COL_PW);
    }
    
    protected boolean isIntegerColumn(String c) {
    	return (c == COL_ID);
    }
    
    public void createTestIdentities() {
    	
    	ContentValues v1 = new ContentValues();
    	v1.put(COL_USER, "hugo");
    	v1.put(COL_PW, "foobar");
    	database.insert(TABLE_NAME, null, v1);
    	
    	ContentValues v2 = new ContentValues();
    	v2.put(COL_USER, "testuser");
    	v2.put(COL_PW, "123456");
    	database.insert(TABLE_NAME, null, v2);
    }
	
}

SQLiteHelper.java

package de.databasetemplate.db;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

/**
 * This class manages database creation and updates.
 * 
 * Based on "Android SQLite Database and ContentProvider - Tutorial" by Lars
 * Vogel. ( http://www.vogella.com/articles/AndroidSQLite/article.html )
 * 
 * @author Andreas Bender
 *
 */
public class SQLiteHelper extends SQLiteOpenHelper {
	
	private static final String DATABASE_NAME = "my_database.db";
	private static final int DATABASE_VERSION = 1;

	private static final String CREATE_IDENTITIES = "create table "
	  + IdentitiesDb.TABLE_NAME + "(" +
      IdentitiesDb.COL_ID + " integer primary key autoincrement, " +
	  IdentitiesDb.COL_USER + " text " +
      IdentitiesDb.COL_PW + " text " +
      ");";
	
	  public SQLiteHelper(Context context) {
	      super(context, DATABASE_NAME, null, DATABASE_VERSION);
	  }

	  @Override
	  public void onCreate(SQLiteDatabase database) {
	      database.execSQL(CREATE_IDENTITIES);
	  }

	  @Override
	  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
	      Log.w(SQLiteHelper.class.getName(),
	        "Upgrading database from version " + oldVersion + " to "
	        + newVersion + ", which will destroy all old data");
	      db.execSQL("DROP TABLE IF EXISTS " + IdentitiesDb.TABLE_NAME);
	      onCreate(db);
	  }

}