Question

我想如果我点击一个列表视图项，我的数据库中的相应数据必须显示在第二个活动textview中我得到了答案但是一个问题我只得到每个类别的最后一个数据。我需要特定类别的每个数据。

这是我从数据库中检索数据的代码

 public class DatabaseHelper extends SQLiteOpenHelper {

public static String DB_PATH = "/data/data/com.example.freshdatabase/databases/";
public static String DB_NAME = "Android.sqlite";
public static final int DB_VERSION = 1;

public static final String TB_USER = "Users";
private SQLiteDatabase myDB;
private Context context;

public DatabaseHelper(Context context) {
    super(context, DB_NAME, null, DB_VERSION);    
    this.context = context;
}

@Override
public void onCreate(SQLiteDatabase db) {
    // TODO Auto-generated method stub

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub

}

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

}
private boolean checkDataBase() {
    SQLiteDatabase tempDB = null;
    try {
        String myPath = DB_PATH + DB_NAME;
        tempDB = SQLiteDatabase.openDatabase(myPath, null,
                SQLiteDatabase.OPEN_READWRITE);
    } catch (SQLiteException e) {
        Log.e("tle99 - check", e.getMessage());
    }
    if (tempDB != null)
        tempDB.close();
    return tempDB != null ? true : false;
}
public void copyDataBase() throws IOException{
    try {
        InputStream myInput = context.getAssets().open(DB_NAME);
        String outputFileName = DB_PATH + DB_NAME;
        OutputStream myOutput = new FileOutputStream(outputFileName);

        byte[] buffer = new byte[1024];
        int length;

        while((length = myInput.read(buffer))>0){
            myOutput.write(buffer, 0, length);
        }

        myOutput.flush();
        myOutput.close();
        myInput.close();
    } catch (Exception e) {
        Log.e("tle99 - copyDatabase", e.getMessage());
    }

}
public void openDataBase() throws SQLException{
    String myPath = DB_PATH + DB_NAME;
    myDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}
public void createDataBase() throws IOException {
    boolean dbExist = checkDataBase();        

    if (dbExist) {

    } else {
        this.getReadableDatabase();
        try {
            copyDataBase();
        } catch (IOException e) {
            Log.e("tle99 - create", e.getMessage());
        }
    }

}

public List<String> getAllUsers(){
    List<String> listUsers = new ArrayList<String>();
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor c;

    try {
        c = db.rawQuery("SELECT * FROM " + TB_USER , null);
        if(c == null) return null;
        String id;
        String name ;
        c.moveToFirst();
        do {  
            name = c.getString(1);            
            listUsers.add(name);
        } while (c.moveToNext()); 
        c.close();
    } catch (Exception e) {
        Log.e("tle99", e.getMessage());
    }

    db.close();        

    return listUsers;
}
public String getPostDesc(String Name){

String  desc = "";
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor c;

    try {
        c = db.rawQuery("Select * from Post INNER JOIN Users ON Users.ID=Post.ID WHERE NAME='"+Name+"'" , null);

        if(c == null) return null;
        while (c.moveToNext()) {
            desc=c.getString(1);

        System.out.println(desc);

        }
        c.close();

    } catch (Exception e) {
        Log.e("tle99", e.getMessage());
    }

    db.close();
    return desc;        



    }

public String getPostdesc(String name){
    String title="";
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor c;

    try {
        c = db.rawQuery("Select * from Post INNER JOIN Users ON Users.ID=Post.ID WHERE NAME='"+name+"'" , null);

        if(c == null) return null;


        if(c.moveToFirst()){
            title= c.getString(2);  

        }

            {
}
            c.close();
    } catch (Exception e) {
        Log.e("tle99", e.getMessage());
    }

    db.close();        

    return title;
    }
}

这是我的主要活动方法代码

public class MainActivity extends ActionBarActivity {

DatabaseHelper dbHeplper;

ListAdapter adapter;

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

    dbHeplper = new DatabaseHelper(getApplicationContext());
    try {
        dbHeplper.createDataBase();
    } catch (IOException e) {
        e.printStackTrace();
    }

    ListView lvUsers= (ListView)findViewById(R.id.lvUsers);
    final List<String> listUsers = dbHeplper.getAllUsers();

    if(listUsers != null){
        adapter = new ArrayAdapter<String>(getApplicationContext(),
                android.R.layout.simple_list_item_1, android.R.id.text1,
                listUsers);
        lvUsers.setAdapter(adapter);


    }
    lvUsers.setOnItemClickListener(new OnItemClickListener() {

        @Override

        public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {

                String Desc =(String) dbHeplper.getPostDesc(listUsers.get(position));
                String title1 =(String) dbHeplper.getPostdesc(listUsers.get(position));

                Toast.makeText(getApplicationContext(),
                  "Desc is: " + Desc,   Toast.LENGTH_LONG)
                  .show();
                Toast.makeText(getApplicationContext(),
                          "Desc is: " + title1,   Toast.LENGTH_LONG)
                          .show();
                Intent newActivity0 = new Intent(MainActivity.this, Second.class);
                newActivity0.putExtra("title", Desc);
                newActivity0.putExtra("title1", title1);
                startActivity(newActivity0);
                }
                }); 


}

这是我的第二项活动代码

Bundle bundle = getIntent().getExtras();
String message = bundle.getString("title");
String message1 = bundle.getString("title1");

TextView txtView = (TextView) findViewById(R.id.textView1);    
txtView.setText(message);

TextView txtView1 = (TextView) findViewById(R.id.TextView2);    
txtView1.setText(message1);

这是我的数据库表

enter image description here

Answer 1

我更改了我的代码，用于从db中检索数据..

public ArrayList<String> getPostname(String Name) {

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

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor c = db.rawQuery("Select * from Post INNER JOIN Users ON Users.ID=Post.ID WHERE NAME='"+Name+"'" , null);;

    try {
        if (c != null) {
            if (c.moveToFirst()) {

                do {
                          String levelData = c.getString(c.getColumnIndex("postname"));
                    List.add("" + levelData);

                        }
                          while (c.moveToNext());
                    }
                }
            } catch (SQLiteException e) {

                    Log.e("Retrieve Data", "Unable to get Data " + e);
            }

            return List;
        }

和onclick

public void onItemClick(AdapterView<?> parent, View view,
                int position, long id) {
            ArrayList<String> post_name = new ArrayList<String>();
            ArrayList<String> post_desc = new ArrayList<String>();

            post_name =(ArrayList<String>) dbHeplper.getPostname(listUsers.get(position));
            post_desc =(ArrayList<String>) dbHeplper.getPostdesc(listUsers.get(position));

现在它完美运作..

从sqlitedatabase中检索数据

1 个答案: