Convert a .sql table into a SQLITE database?

Question

I have a database on my computer (localhost) holding thousands of records. I just want to convert the table containing those records into a database that can be accessed on Android. I heard of SQLite, but is there anyway to convert a .sql file to an SQLite database and store it offline on my android phone?

Answer 1

Yes, you could do that. First you would need to convert your .sql file into a sqlite database that android can understand. In your new sqlite schema, you would need

1. android_metadata table, and insert a locale row. I set mine to "en_US"

   CREATE TABLE android_metadata (locale TEXT)

2. a table to hold your data. You can name this table whatever you prefer, but make sure that you have _id as your primary key. For example

   CREATE TABLE mydata (_id INTEGER PRIMARY KEY, data TEXT)

You then need to import your data from the .sql file to your new data table. You may find SQLiteBrowser useful http://sourceforge.net/projects/sqlitebrowser/

Once you've done that, you now have a sqlite database that you can load, and read from your android app.

Copy your sqlite database to your android project assets folder. Then you can create your database helper that will open and construct an offline sqlite database that your app could access.

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

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

public class MyDbHelper extends SQLiteOpenHelper {
    // The Android's default system path of your application database.
    private static String DB_PATH = "/data/data/yourpackagename/databases/";

    private static String DB_NAME = "your_db_name.db";

    private static final String DATA_TABLE_NAME = "your_data_table_name";
    private static final String COLUMN_YOUR_DATA_COLUMN_NAME = "data";

    private SQLiteDatabase myDataBase;

    private final Context myContext;

    /**
     * Constructor: MyDbHelper Takes and keeps a reference of the passed context
     * in order to access to the application assets and resources.
     * 
     * @param context
     */
    public MyDbHelper(Context context) {
        super(context, DB_NAME, null, 1);
        this.myContext = context;
    }

    /**
     * Function: createDataBase() Creates a empty database on the system and
     * rewrites it with your own database.
     */
    public void createDataBase() throws IOException {

        boolean dbExist = checkDataBase();

        if (dbExist) {
            Log.i("info", "db exists. do nothing");
            // do nothing - database already exist
        } else {

            // By calling this method and empty database will be created into
            // the default system path
            // of your application so we are gonna be able to overwrite that
            // database with our database.
            Log.i("info", "creating new db");
            this.getReadableDatabase();
            this.close();

            try {
                copyDataBase();
            } catch (IOException e) {
                close();
                throw new Error("Error copying database");
            }
        }
    }

    /**
     * Function: checkDataBase() Check if the database already exist to avoid
     * re-copying the file each time you open the application.
     * 
     * @return true if it exists, false if it doesn't
     */
    private boolean checkDataBase() {

        SQLiteDatabase checkDB = null;

        try {
            String myPath = DB_PATH + DB_NAME;
            checkDB = SQLiteDatabase.openDatabase(myPath, null,
                    SQLiteDatabase.OPEN_READONLY);

        } catch (SQLiteException e) {
            // database does't exist yet.
        }

        if (checkDB != null) {
            checkDB.close();
        }

        return checkDB != null ? true : false;
    }

    /**
     * Function: copyDataBase() Copies your database from your local
     * assets-folder to the just created empty database in the system folder,
     * from where it can be accessed and handled. This is done by transfering
     * bytestream.
     */
    private void copyDataBase() throws IOException {

        // Open your local db as the input stream
        InputStream myInput = myContext.getAssets().open(DB_NAME);

        // Path to the just created empty db
        String outFileName = DB_PATH + DB_NAME;

        // Open the empty db as the output stream
        OutputStream myOutput = new FileOutputStream(outFileName);

        // transfer bytes from the inputfile to the outputfile
        byte[] buffer = new byte[1024];
        int length;
        while ((length = myInput.read(buffer)) > 0) {
            myOutput.write(buffer, 0, length);
        }

        // Close the streams
        myOutput.flush();
        myOutput.close();
        myInput.close();

    }

    /**
     * Function: openDataBase()
     * 
     */
    public void openDataBase() throws SQLException {
        // Open the database
        String myPath = DB_PATH + DB_NAME;
        myDataBase = SQLiteDatabase.openDatabase(myPath, null,
                SQLiteDatabase.OPEN_READONLY);
    }

    /**
     * Function: close()
     * 
     * @Override close() method
     */
    @Override
    public synchronized void close() {

        if (myDataBase != null)
            myDataBase.close();
        super.close();

    }

    /**
     * Function: onCreate()
     * 
     * @Override onCreate() method
     */
    @Override
    public void onCreate(SQLiteDatabase db) {

    }

    /**
     * Function: onUpgrade()
     * 
     * @Override onUpgrade() method
     */
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {

    }
    // Add your public helper methods to access and get content from the
    // database.
    // You could return cursors by doing "return myDataBase.query(....)" so it'd
    // be easy
    // to you to create adapters for your views.

}