DictionaryDatabase.java Source code

Introduction

Here is the source code for DictionaryDatabase.java

Source

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

public class DictionaryDatabase extends SQLiteOpenHelper {

    private static final String DATABASE_NAME = "dictionary.db";
    private static final int DATABASE_VERSION = 1;

    private static final String TABLE_DICTIONARY = "dictionary";
    private static final String FIELD_WORD = "word";
    private static final String FIELD_DEFINITION = "definition";

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

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("CREATE TABLE " + TABLE_DICTIONARY + "(_id integer PRIMARY KEY," + FIELD_WORD + " TEXT, "
                + FIELD_DEFINITION + " TEXT);");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        //Nothing to do
    }

    public void saveRecord(String word, String definition) {
        long id = findWordID(word);
        if (id > 0) {
            updateRecord(id, word, definition);
        } else {
            addRecord(word, definition);
        }
    }

    public long addRecord(String word, String definition) {
        SQLiteDatabase db = getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(FIELD_WORD, word);
        values.put(FIELD_DEFINITION, definition);
        return db.insert(TABLE_DICTIONARY, null, values);
    }

    public int updateRecord(long id, String word, String definition) {
        SQLiteDatabase db = getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put("_id", id);
        values.put(FIELD_WORD, word);
        values.put(FIELD_DEFINITION, definition);
        return db.update(TABLE_DICTIONARY, values, "_id = ?", new String[] { String.valueOf(id) });
    }

    public int deleteRecord(long id) {
        SQLiteDatabase db = getWritableDatabase();
        return db.delete(TABLE_DICTIONARY, "_id = ?", new String[] { String.valueOf(id) });
    }

    public long findWordID(String word) {
        long returnVal = -1;
        SQLiteDatabase db = getReadableDatabase();

        Cursor cursor = db.rawQuery("SELECT _id FROM " + TABLE_DICTIONARY + " WHERE " + FIELD_WORD + " = ?",
                new String[] { word });
        if (cursor.getCount() == 1) {
            cursor.moveToFirst();
            returnVal = cursor.getInt(0);
        }
        return returnVal;
    }

    public String getDefinition(long id) {
        String returnVal = "";
        SQLiteDatabase db = getReadableDatabase();
        Cursor cursor = db.rawQuery("SELECT definition FROM " + TABLE_DICTIONARY + " WHERE  _id = ?",
                new String[] { String.valueOf(id) });
        if (cursor.getCount() == 1) {
            cursor.moveToFirst();
            returnVal = cursor.getString(0);
        }
        return returnVal;
    }

    public Cursor getWordList() {
        SQLiteDatabase db = getReadableDatabase();
        if (db == null)
            return null;
        String query = "SELECT _id, " + FIELD_WORD + " FROM " + TABLE_DICTIONARY + " ORDER BY " + FIELD_WORD
                + " ASC";
        return db.rawQuery(query, null);
    }
}