我只想打印出我的两列数据库，但TextView中只显示了一列。第一列是用户输入，第二列是用户输入的日期。我很确定问题是在MyDBHandler.java类的databaseToString（）方法中的第二个while循环中，或者在Product.java类中的getter和setter中。
MyDBHandler.java
public class MyDBHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "productDB.db";
public static final String KICK_TABLE = "products";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_PRODUCTNAME = "productname";
public static final String COLUMN_PRODUCTNAME_DATE = "productnamedate";
//We need to pass database information along to superclass
public MyDBHandler(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {
super(context, DATABASE_NAME, factory, DATABASE_VERSION);
}
/*
CREATE TABLE table_name (
column_1 data_type,
column_2 data_type,
column_3 data_type
);
*/
@Override
public void onCreate(SQLiteDatabase db) {
String query = "CREATE TABLE " +
KICK_TABLE + "(" +
COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " +
COLUMN_PRODUCTNAME + " TEXT, " +
COLUMN_PRODUCTNAME_DATE + " TEXT);";
db.execSQL(query);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + KICK_TABLE);
onCreate(db);
}
//Add a new row to the database
public void addProduct(Product product){
SQLiteDatabase db = getWritableDatabase();
ContentValues values = new ContentValues();
values.put(COLUMN_PRODUCTNAME, product.get_productname());
db.insert(KICK_TABLE, null, values);
db.close();
}
//Add a new row to the database
public void addProductDate(Product productdate){
SQLiteDatabase db = getWritableDatabase();
ContentValues values = new ContentValues();
values.put(COLUMN_PRODUCTNAME_DATE, productdate.get_productnamedate());
db.insert(KICK_TABLE, null, values);
db.close();
}
//Delete a product from the database
public void deleteProduct(String productName){
SQLiteDatabase db = getWritableDatabase();
db.execSQL("DELETE FROM " + KICK_TABLE + " WHERE " + COLUMN_PRODUCTNAME + "=\"" + productName + "\";");
}
public Integer dbSize(){
SQLiteDatabase db = getWritableDatabase();
Cursor mCount = db.rawQuery("SELECT count(" + COLUMN_PRODUCTNAME + ") FROM " + KICK_TABLE, null);
mCount.moveToFirst();
int count = mCount.getInt(0);
mCount.close();
return count;
}
public String databaseToString(){
String dbString = "";
SQLiteDatabase db = getWritableDatabase();
String query = "SELECT * FROM " + KICK_TABLE + " WHERE 1";
//Cursor points to a location in your results
Cursor c = db.rawQuery(query, null);
//Move to the first row in your results
c.moveToFirst();
//Position after the last row means the end of the results
while (!c.isAfterLast()) {
if (c.getString(c.getColumnIndex("productname")) != null) {
dbString += c.getString(c.getColumnIndex("productname"));
dbString += "\n";
}
c.moveToNext();
}
//this is the sql date attempt
c.getColumnIndex("productnamedate");
c.moveToFirst();
//Position after the last row means the end of the results
while (!c.isAfterLast()) {
if (c.getString(c.getColumnIndex("productnamedate")) != null) {
dbString += c.getString(c.getColumnIndex("productnamedate"));
dbString += "\n";
}
c.moveToNext();
}
db.close();
return dbString;
}
Product.java
public class Product {
private int _id;
private String _productname;
private String _productnamedate;
public Product(){
}
public Product(String productname){
this._productname = productname;
}
public void set_id(int _id) {
this._id = _id;
}
public void set_productname(String _productname) {
this._productname = _productname;
}
public void set_productnamedate(String _productnamedate) {
this._productnamedate = _productnamedate;
}
public int get_id() {
return _id;
}
public String get_productname() {
return _productname;
}
public String get_productnamedate() {
return _productnamedate;
}
}
KickCounter.java
public class KickCounter extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private OnFragmentInteractionListener mListener;
public KickCounter() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* @param param1 Parameter 1.
* @param param2 Parameter 2.
* @return A new instance of fragment KickCounter.
*/
// TODO: Rename and change types and number of parameters
public static KickCounter newInstance(String param1, String param2) {
KickCounter fragment = new KickCounter();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
//SQLite
//Add a product to the database
/*public void addButtonClicked(View view){
Product product = new Product(kickString);
dbHandler.addProduct(product);
printDatabase();
}*/
Button kickButton;
Button removeKickButton;
Button startButton;
Chronometer chronometer;
TextView kickCount;
Integer kick = 0;
//SQLite
TextView sQLiteOutput;
//SQLite
MyDBHandler dbHandler;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_kick_counter, container, false);
kickButton = (Button)rootView.findViewById(R.id.kick_button_ID);
kickButton.setVisibility(View.INVISIBLE);
removeKickButton = (Button)rootView.findViewById(R.id.remove_kick_button_ID);
removeKickButton.setVisibility(View.INVISIBLE);
startButton = (Button)rootView.findViewById(R.id.start_button_ID);
chronometer = (Chronometer)rootView.findViewById(R.id.chronometer_ID);
kickCount = (TextView)rootView.findViewById(R.id.kickCount_ID);
sQLiteOutput = (TextView)rootView.findViewById(R.id.SQLiteOutput_ID);
//SQLite
dbHandler = new MyDBHandler(getContext(), null, null, 1);
// printDatabase();
String dbString = dbHandler.databaseToString();
sQLiteOutput.setText(dbString);
startButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startButton.setVisibility(View.GONE);
kickButton.setVisibility(View.VISIBLE);
removeKickButton.setVisibility(View.VISIBLE);
//trying to make SQL date work here
String dateString = new SimpleDateFormat("yyyy-MM-dd").format(new Date());
chronometer.setBase(SystemClock.elapsedRealtime());
chronometer.start();
chronometer.setOnChronometerTickListener(new Chronometer.OnChronometerTickListener() {
@Override
public void onChronometerTick(Chronometer chronometer) {
if( chronometer.getText().toString().equalsIgnoreCase("00:05")) {
Snackbar.make(getView(),"Your text",Snackbar.LENGTH_LONG).show();
end();
}
if(kick == 10) {
Snackbar.make(getView(),"heo",Snackbar.LENGTH_INDEFINITE).show();
end();
}
}
});
}
});
kickButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(kick < 10){
kick++;
setKickCountText();
}
else{
return;
}
}
});
removeKickButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if(kick != 0){
kick--;
setKickCountText();
}
else{
return;
}
}
});
// Inflate the layout for this fragment
return rootView;
}
public void end(){
chronometer.stop();
kickButton.setVisibility(View.GONE);
removeKickButton.setVisibility(View.GONE);
String kickString = kick.toString();
String dateString = "hello";//new SimpleDateFormat("yyyy-MM-dd").format(new Date());
Product product = new Product(kickString);
Product productDate = new Product(dateString);
dbHandler.addProduct(product);
dbHandler.addProductDate(productDate);
printDatabase();
}
//SQLite
//Print the database
public void printDatabase(){
String dbString = dbHandler.databaseToString();
sQLiteOutput.setText(dbString);
//buckysInput.setText("");
}
public void setKickCountText(){
kickCount.setText(kick.toString());
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
@Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
@Override
public void onDetach() {
super.onDetach();
mListener = null;
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
答案 0 :(得分：3)
您实际上是插入两个不同的行，而不是一个：
dbHandler.addProduct(product);
dbHandler.addProductDate(productDate);
每次将数据插入表格时，都会插入两行：
-----------------------------------------------
| Id | product_name | product_date |
-----------------------------------------------
| 1 | SOME_NAME | null |
-----------------------------------------------
| 2 | null | SOME_DATE |
-----------------------------------------------
要解决此问题，请使用1插入方法而不是2：
//Add a new row to the database
public void addProduct(Product product, Product productdate){
SQLiteDatabase db = getWritableDatabase();
ContentValues values = new ContentValues();
values.put(COLUMN_PRODUCTNAME, product.get_productname());
values.put(COLUMN_PRODUCTNAME_DATE, productdate.get_productnamedate());
db.insert(KICK_TABLE, null, values);
db.close();
}