ANDROID / SQLite搜索记录

Question

I'm developing a symptoms checker application. My application has a listview with checkbox (from android.R.layout.simple_list_item_multiple_choice ).

After checking the following symptoms and clicking the DONE button, the app should display the possible conditions the user may have. Information are already stored in my prepopulated SQLite database. For your info, please refer to this screenshot:

This is what I have so far: ( Symptoms.java )

       public void onClick(View v) {
    // TODO Auto-generated method stub

    /*Intent i = new Intent(this, SymptomsResult.class);
    startActivity(i);
    finish();*/

    dbHelper = new DBHelper(this);
      dbHelper.openDataBase();

      String c = dbHelper.getData();

    String selected = "";
    int cntChoice = lv.getCount();

    SparseBooleanArray sparseBooleanArray = lv.getCheckedItemPositions();

    for(int i = 0; i < cntChoice; i++){

        if(sparseBooleanArray.get(i)) {
            selected += lv.getItemAtPosition(i).toString() + "\n";
        }

    }

    c.equals(selected);

    dbHelper.close();


    Toast.makeText(this, selected, Toast.LENGTH_LONG).show();       

}

DBHelper.java

     public class DBHelper extends SQLiteOpenHelper{

//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.fps.myheartfirst/databases/";
private static String DB_NAME = "mhfDB";
private static String KEY_CONDITIONS = "conditions";
private static String KEY_SYMPTOMS = "symptoms";
private static String DB_TABLE = "tblSymptoms";
private SQLiteDatabase myDataBase; 
private final Context myContext;

/**
 * Constructor
 * Takes and keeps a reference of the passed context in order to access to the application assets and resources.
 * @param context
 */

public DBHelper(Context context) {
    super(context, DB_NAME, null, 1);
    this.myContext = context;
}   

/**
 * Creates a empty database on the system and rewrites it with your own database.
 * */

public void createDataBase() throws IOException{

    boolean dbExist = checkDataBase();

    myDataBase = null;

     if (dbExist) {
            // do nothing - database already exist
        } else {

            // By calling this method and empty database will be created into
            // the default system path

            myDataBase = this.getReadableDatabase(); 
            myDataBase.close();


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

/**
 * 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 doesn't exist yet.
    }
    if(checkDB != null){
        checkDB.close();
    }

    return checkDB != null ? true : false;
}

/**
 * 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();

}

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

public String getData() {

    String search = "";

    Cursor c = myDataBase.rawQuery("SELECT " + KEY_CONDITIONS + " FROM " + DB_TABLE + 
            " WHERE " + KEY_SYMPTOMS + " = '" 
    + search + "'", null);
            //new String[] { name }, null, null, null);

    int iRow = c.getColumnIndex(KEY_CONDITIONS);

    for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
        search = search + c.getString(iRow);
    }

    return search;

}

My problem is that, how can I put the String query for my Symptoms class? I'm kinda new to database programming so I beg your pardon.

I believe in this line I have to put something:

   c.equals(selected);

    dbHelper.close();


    Toast.makeText(this, selected, Toast.LENGTH_LONG).show();

So a toast will be displayed to user to view the possible conditions. Does anybody here know how to accomplish this? I'd appreciate your help. Thanks.

Answer 1

public String getData( String search) {

 Cursor c = myDataBase.query("SELECT " + KEY_CONDITIONS + " FROM " + DB_TABLE + 
        " WHERE " + KEY_SYMPTOMS + " = '" 
+ search + "'", null);

Cursor c = myDataBase.query(DB_TABLE ,KEY_SYMPTOMS+ " = ?",new String[]{search},null,null,null);


int iRow = c.getColumnIndex(KEY_CONDITIONS);

for(c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {
    search = search + c.getString(iRow);
}

return search;

}

pass the search word to getData() method

Answer 2

Change the getData method as given below -

public String getData(String [] symptoms) {
    String search = null;
    Cursor c = myDataBase.query(DB_TABLE, new String [] {KEY_CONDITIONS}, KEY_SYMPTOMS + "= ? ", symptoms, null, null, null);

    c.moveToFirst();

    while (c.isAfterLast() == false) {
        search = "" + c.getString(0);
        c.moveToNext();
    }

    return search;

}

And in the Symptoms class - change the onClick as -

public void onClick(View v) {

    ArrayList<String> alSymptoms = new ArrayList<String>();


    dbHelper = new DBHelper(this);

    try {

        dbHelper.createDataBase();

    } catch (IOException ioe) {

        throw new Error("Unable to create database");

    }

    try {

        dbHelper.openDataBase();

    } catch (SQLException sqle) {

        throw sqle;

    }



    String selected = "";

    int cntChoice = lv.getCount();

    SparseBooleanArray sparseBooleanArray = lv.getCheckedItemPositions();

    for (int i = 0; i < cntChoice; i++) {

        if (sparseBooleanArray.get(i)) {

            //Log.i("Selected", lv.getItemAtPosition(i).toString());
            //selected += lv.getItemAtPosition(i).toString() + "\n";
            alSymptoms.add(lv.getItemAtPosition(i).toString());
        }

    }
    String [] symptoms = alSymptoms.toArray(new String[alSymptoms.size()]);

    String c = dbHelper.getData(symptoms);

    Toast.makeText(this, c, Toast.LENGTH_LONG).show();

    dbHelper.close();
}