Database Manager for Android

Database_DatabaseHelper.java

package merlini.mvcpattern.Database;

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

/**
 * Created by mattia on 16/12/15.
 */
public class DatabaseHelper extends SQLiteOpenHelper {
    public static String CREATE_DATABASE =
            "CREATE TABLE Utenti" +
                    "(" +
                    "id INT PRIMARY KEY," +
                    "nome VARCHAR(300) NOT NULL," +
                    "cognome VARCHAR(300) NOT NULL," +
                    "email VARCHAR(300) NOT NULL," +
                    "psw VARCHAR(300) NOT NULL" +
                    ")";
    private String dbName;

    public DatabaseHelper(Context context, String dbName) {
        super(context, dbName, null, 1);
        this.dbName = dbName;
        //context.deleteDatabase(dbName);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        //Se all'avvio non trova nessun database già creato
        db.execSQL(DatabaseHelper.CREATE_DATABASE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
}

Database_QueryManager.java

package merlini.mvcpattern.Database;

import android.content.ContentValues;
import android.database.Cursor;

/**
 * Created by mattia on 23/12/15.
 */
public abstract class QueryManager {
    private TableManager tableManager;

    public QueryManager(TableManager tableManager) {
        this.tableManager = tableManager;
    }

    /**
     * Query Manager for select queries
     *
     * @param distinct
     * @param columns
     * @param where
     * @param whereArgs
     * @param groupBy
     * @param having
     * @param orderBy
     * @param limit
     */
    public void select(boolean distinct, String[] columns, String where, String[] whereArgs, String groupBy, String having, String orderBy, String limit) {
        Cursor cursor = this.tableManager.select(distinct, columns, where, whereArgs, groupBy, having, orderBy, limit);
        this.onBeforeSelectIterations();
        while (cursor.moveToNext()) {
            this.onSelectIteration(cursor);
        }
        this.onAfterSelectIterations();
    }

    /**
     * Query Manager for insert queries
     *
     * @param values
     */
    public void insert(ContentValues values) {
        this.onInsertResult(this.tableManager.insert(values));
    }

    /**
     * Query Manager for update queries
     *
     * @param updatedValues
     * @param where
     * @param bindArray
     */
    public void update(ContentValues updatedValues, String where, String[] bindArray) {
        this.onUpdateResult(this.tableManager.update(updatedValues, where, bindArray));
    }

    /**
     * Query Manager for delete queries
     *
     * @param where
     * @param whereArgs
     */
    public void delete(String where, String[] whereArgs) {
        this.onDeleteResult(this.tableManager.delete(where, whereArgs));
    }

    /**
     * Code executed before the select loop.
     * Example:
     * //Code executed here
     * while(cursor.moveToNext()) {...}
     */
    protected abstract void onBeforeSelectIterations();

    /**
     * Code executed within the select loop.
     *
     * @param cursor Cursor
     *               <p/>
     *               Example:
     *               while(...)
     *               {
     *               //Code executed here
     *               //Ex: cursor.getString(cursor.getColumnsIndex("field");
     *               }
     */
    protected abstract void onSelectIteration(Cursor cursor);

    /**
     * Code executed after the select loop.
     * Example:
     * while(cursor.moveToNext()) {...}
     * //Code executed here
     */
    protected abstract void onAfterSelectIterations();

    /**
     * Code executed after the insert query has returned a boolean result
     *
     * @param insert boolean
     */
    protected abstract void onInsertResult(boolean insert);

    /**
     * Code executed after the update query has returned a boolean result
     *
     * @param update boolean
     */
    protected abstract void onUpdateResult(boolean update);

    /**
     * Code executed after the delete query has returned a boolean result
     *
     * @param delete boolean
     */
    protected abstract void onDeleteResult(boolean delete);
}

Database_TableManager.java

package merlini.mvcpattern.Database;

import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;

import merlini.mvcpattern.Base.Console;

/**
 * Created by mattia on 16/12/15.
 *
 * @author Mattia Merlini
 */
public class TableManager {
    private String tableName;
    private DatabaseHelper databaseHelper;

    public TableManager(String tableName, DatabaseHelper databaseHelper) {
        this.tableName = tableName;
        this.databaseHelper = databaseHelper;
    }

    /**
     * Retrieves records from database
     * Example:
     * ...select(false, String[] {"id", "name"},
     * "id=? AND name=?",
     * String[] {"10", "mattia"},
     * "name", null, "name, id", "0, 100");
     * Explained:
     * SELECT id, name FROM tableName WHERE id="10" AND name="mattia" GROUP BY name ORDER BY name, id LIMIT 0, 100;
     */
    synchronized public Cursor select(boolean distinct, String[] columns, String where, String[] whereArgs, String groupBy, String having, String orderBy, String limit) {
        Cursor cursor = null;
        try {
            SQLiteDatabase db = this.databaseHelper.getReadableDatabase();
            cursor = db.query(distinct, this.tableName, columns, where, whereArgs, groupBy, having, orderBy, limit);
        } catch (SQLiteException e) {
            Console.log(e);
        }
        return cursor;
    }

    /**
     * Inserts records to database
     * Example:
     * ContentValues v = new ContentValues();
     * v.put("id", "10");
     * v.put("name", "mattia");
     * ...insert(v);
     * Explained: INSERT INTO tableName (id, name) VALUES ("10", "mattia");
     */
    synchronized public boolean insert(ContentValues values) {
        try (SQLiteDatabase db = this.databaseHelper.getWritableDatabase()) {
            db.insert(this.tableName, null, values);
            return true;
        } catch (SQLiteException e) {
            Console.log(e);
            return false;
        }
    }

    /**
     * Updates records to database
     * Example:
     * ContentValues v = new ContentValues();
     * v.put("id", "10");
     * v.put("name", "mattia");
     * ...update(v, "id=? AND name=?", String[] {"11", "merlini"});
     * Explained: UPDATE tableName SET id=10, name="mattia" WHERE id="11" AND name="merlini";
     */
    synchronized public boolean update(ContentValues updatedValues, String where, String[] bindArray) {
        try (SQLiteDatabase db = this.databaseHelper.getWritableDatabase()) {
            db.update("Tabella", updatedValues, where, bindArray);
            return true;
        } catch (SQLiteException e) {
            Console.log(e);
            return false;
        }
    }

    /**
     * Deletes records to database
     * Example:
     * ...delete("id=? AND name=?", String[] {"10", "mattia"});
     * Explained: DELETE FROM tableName WHERE id=10 AND name="mattia";
     */
    synchronized public boolean delete(String where, String[] whereArgs) {
        try (SQLiteDatabase db = this.databaseHelper.getWritableDatabase()) {
            db.delete(this.tableName, where, whereArgs);
            return true;
        } catch (SQLiteException e) {
            Console.log(e);
            return false;
        }
    }
}