Как подключить базу данных SQLite в Android приложение[:en]How to connect a SQLite database to an Android application

Есть много уроков о том, как создать и редактировать базы данных SQLite в android приложениях, но как использовать готовую базу данных в приложении, как импортировать созданные базы данных SQLite в android проект?

В самом деле, многие разработчики сталкиваются с проблемами ввода данных, когда речь идет о тестирование существующей базы данных, много людей не имеют времени, чтобы создать новую базу и реализовать все методы CRUD, они просто хотят использовать существующую SQLite базу данных .

В этом уроке вы узнаете, как создать базу данных SQLite с помощью SQLite Software Manager, и импортировать созданную БД в андроид-проект, используя  Android SQLite API.

https://youtu.be/iE_bsPfB00w

Исходный код проекта:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".CopyDbActivity">

    <Button
        android:id="@+id/button01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Copy Database"></Button>


</LinearLayout>

import android.database.Cursor;
import android.database.SQLException;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import java.io.IOException;

public class CopyDbActivity extends AppCompatActivity {

    Cursor c = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_copy_db);

        ((Button) findViewById(R.id.button01)).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DatabaseHelper myDbHelper = new DatabaseHelper(CopyDbActivity.this);
                try {
                    myDbHelper.createDataBase();
                } catch (IOException ioe) {
                    throw new Error("Unable to create database");
                }
                try {
                    myDbHelper.openDataBase();
                } catch (SQLException sqle) {
                    throw sqle;
                }
                Toast.makeText(CopyDbActivity.this, "Success", Toast.LENGTH_SHORT).show();
                c = myDbHelper.query("EMP_TABLE", null, null, null, null, null, null);
                if (c.moveToFirst()) {
                    do {
                        Toast.makeText(CopyDbActivity.this,
                                "_id: " + c.getString(0) + "\n" +
                                        "E_NAME: " + c.getString(1) + "\n" +
                                        "E_AGE: " + c.getString(2) + "\n" +
                                        "E_DEPT:  " + c.getString(3),
                                Toast.LENGTH_LONG).show();
                    } while (c.moveToNext());
                }
            }
        });

    }


}

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

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Created by Aylar-HP on 12/10/2015.
 */
public class DatabaseHelper extends SQLiteOpenHelper {

    String DB_PATH = null;
    private static String DB_NAME = "extenalDB";
    private SQLiteDatabase myDataBase;
    private final Context myContext;

    public DatabaseHelper(Context context) {
        super(context, DB_NAME, null, 10);
        this.myContext = context;
        this.DB_PATH = "/data/data/" + context.getPackageName() + "/" + "databases/";
        Log.e("Path 1", DB_PATH);
    }


    public void createDataBase() throws IOException {
        boolean dbExist = checkDataBase();
        if (dbExist) {
        } else {
            this.getReadableDatabase();
            try {
                copyDataBase();
            } catch (IOException e) {
                throw new Error("Error copying database");
            }
        }
    }

    private boolean checkDataBase() {
        SQLiteDatabase checkDB = null;
        try {
            String myPath = DB_PATH + DB_NAME;
            checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
        } catch (SQLiteException e) {
        }
        if (checkDB != null) {
            checkDB.close();
        }
        return checkDB != null ? true : false;
    }

    private void copyDataBase() throws IOException {
        InputStream myInput = myContext.getAssets().open(DB_NAME);
        String outFileName = DB_PATH + DB_NAME;
        OutputStream myOutput = new FileOutputStream(outFileName);
        byte[] buffer = new byte[10];
        int length;
        while ((length = myInput.read(buffer)) > 0) {
            myOutput.write(buffer, 0, length);
        }
        myOutput.flush();
        myOutput.close();
        myInput.close();

    }

    public void openDataBase() throws SQLException {
        String myPath = DB_PATH + DB_NAME;
        myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

    }

    @Override
    public synchronized void close() {
        if (myDataBase != null)
            myDataBase.close();
        super.close();
    }


    @Override
    public void onCreate(SQLiteDatabase db) {
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        if (newVersion > oldVersion)
            try {
                copyDataBase();
            } catch (IOException e) {
                e.printStackTrace();

            }
    }

    public Cursor query(String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy) {
        return myDataBase.query("EMP_TABLE", null, null, null, null, null, null);
    }


}

Источник[:en]There are many lessons on how to create and edit SQLite databases in android applications, but how to use the finished database in the application, how to import the created SQLite databases into the android project?

In fact, many developers are faced with data entry problems when it comes to testing an existing database, many people do not have time to create a new database and implement all CRUD methods, they just want to use the existing SQLite database.

In this lesson, you will learn how to create a SQLite database with SQLite Software Manager, and import the created database into an android project using the Android SQLite API.

https://youtu.be/iE_bsPfB00w

Project source code:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".CopyDbActivity">

    <Button
        android:id="@+id/button01"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Copy Database"></Button>


</LinearLayout>

import android.database.Cursor;
import android.database.SQLException;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

import java.io.IOException;

public class CopyDbActivity extends AppCompatActivity {

    Cursor c = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_copy_db);

        ((Button) findViewById(R.id.button01)).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DatabaseHelper myDbHelper = new DatabaseHelper(CopyDbActivity.this);
                try {
                    myDbHelper.createDataBase();
                } catch (IOException ioe) {
                    throw new Error("Unable to create database");
                }
                try {
                    myDbHelper.openDataBase();
                } catch (SQLException sqle) {
                    throw sqle;
                }
                Toast.makeText(CopyDbActivity.this, "Success", Toast.LENGTH_SHORT).show();
                c = myDbHelper.query("EMP_TABLE", null, null, null, null, null, null);
                if (c.moveToFirst()) {
                    do {
                        Toast.makeText(CopyDbActivity.this,
                                "_id: " + c.getString(0) + "\n" +
                                        "E_NAME: " + c.getString(1) + "\n" +
                                        "E_AGE: " + c.getString(2) + "\n" +
                                        "E_DEPT:  " + c.getString(3),
                                Toast.LENGTH_LONG).show();
                    } while (c.moveToNext());
                }
            }
        });

    }


}

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

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * Created by Aylar-HP on 12/10/2015.
 */
public class DatabaseHelper extends SQLiteOpenHelper {

    String DB_PATH = null;
    private static String DB_NAME = "extenalDB";
    private SQLiteDatabase myDataBase;
    private final Context myContext;

    public DatabaseHelper(Context context) {
        super(context, DB_NAME, null, 10);
        this.myContext = context;
        this.DB_PATH = "/data/data/" + context.getPackageName() + "/" + "databases/";
        Log.e("Path 1", DB_PATH);
    }


    public void createDataBase() throws IOException {
        boolean dbExist = checkDataBase();
        if (dbExist) {
        } else {
            this.getReadableDatabase();
            try {
                copyDataBase();
            } catch (IOException e) {
                throw new Error("Error copying database");
            }
        }
    }

    private boolean checkDataBase() {
        SQLiteDatabase checkDB = null;
        try {
            String myPath = DB_PATH + DB_NAME;
            checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
        } catch (SQLiteException e) {
        }
        if (checkDB != null) {
            checkDB.close();
        }
        return checkDB != null ? true : false;
    }

    private void copyDataBase() throws IOException {
        InputStream myInput = myContext.getAssets().open(DB_NAME);
        String outFileName = DB_PATH + DB_NAME;
        OutputStream myOutput = new FileOutputStream(outFileName);
        byte[] buffer = new byte[10];
        int length;
        while ((length = myInput.read(buffer)) > 0) {
            myOutput.write(buffer, 0, length);
        }
        myOutput.flush();
        myOutput.close();
        myInput.close();

    }

    public void openDataBase() throws SQLException {
        String myPath = DB_PATH + DB_NAME;
        myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);

    }

    @Override
    public synchronized void close() {
        if (myDataBase != null)
            myDataBase.close();
        super.close();
    }


    @Override
    public void onCreate(SQLiteDatabase db) {
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        if (newVersion > oldVersion)
            try {
                copyDataBase();
            } catch (IOException e) {
                e.printStackTrace();

            }
    }

    public Cursor query(String table, String[] columns, String selection, String[] selectionArgs, String groupBy, String having, String orderBy) {
        return myDataBase.query("EMP_TABLE", null, null, null, null, null, null);
    }


}

Источник