Question

我想编写一个Android应用程序，用户可以在EditBox中键入内容，然后应用程序搜索SQL数据库并在ListView中列出结果。

我有以下问题：

我已经使用DatabBaseHelper类导入了数据库，但现在我不知道如何从键入EditBox的Text中进行搜索查询。有人可以解释一下怎么做吗？

感谢您提供的每一个有用的帮助!!

DataBaseHelper类：

      public class DataBaseHelper extends SQLiteOpenHelper{

    //The Android's default system path of your application database.
    private static String DB_PATH = "/data/data/com.test.sql/databases/";

    private static String DB_NAME = "demo";

    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 DataBaseHelper(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();

    if(dbExist){
    //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.
    this.getReadableDatabase();

    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 does'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.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) {

    }

    // 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.

    }

Answer 1

创建一个EditText和addTextWatcher，在textChange方法之后调用方法执行以下操作：

public void setUpSearchList()
    {


     items.add(new SectionItem(cTag.getString(0)));
     Title=db.rawQuery("SELECT TITLE,EDATE,CHECKED,ID FROM Task WHERE TAG=? and TITLE LIKE ?",new String []{cTag.getString(0),text.getText()+"%"});
}

获取该记录并将其与listview绑定，不要忘记notifyDataSetChanged.Further帮助转到此链接http://www.indiesapps.com/blog/link-up-the-list-view-with-searching-functionality-to-provide-ease-of-access/

如何通过Android中的数据库进行搜索查询

1 个答案: