0
проверить, если строка уже существует в базе данных SQLite
LogCat error:
FATAL EXCEPTION: main
Process: com.sam.shoppingcart, PID: 31773
android.database.sqlite.SQLiteException: near "Beef": syntax error (code 1): , while compiling: SELECT KEY_NAME FROM shop WHERE KEY_NAME=Corned Beef
at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:893)
at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:504)
at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1339)
at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1278)
at com.sam.shoppingcart.SQLiteHandler.ifExists(SQLiteHandler.java:63)
at com.sam.shoppingcart.CustomListAdapter$1.onClick(CustomListAdapter.java:77)У меня есть ListView с помощью пользовательского адаптера с «Добавить» и «Удалить» кнопку. При нажатии кнопки «Добавить» в базу данных добавляются данные «Имя и цена» элемента LV. Я хочу проверить при добавлении, если элемент LV уже присутствует в БД или нет. Для этого я создал функцию ifExists (модель) в DBHandler. Но теперь при нажатии кнопки «Добавить» это дает мне ошибку. Что я делаю неправильно? PS: Я получил функцию от here.
public class MainActivity extends AppCompatActivity {
private ListView listView;
private ArrayList<Model> mListData;
private CustomListAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
listView = (ListView)findViewById(R.id.list);
mListData = new ArrayList<>();
mListData.add(new Model("Beef Manhattan", "50"));
mListData.add(new Model("Chicken Fried Steak", "90"));
mListData.add(new Model("Corned Beef", "100"));
mListData.add(new Model("Domesticated Turkey", "80"));
mListData.add(new Model("Eggs Benedict", "10"));
mListData.add(new Model("French Dip", "20"));
mListData.add(new Model("Green Bean Casserole", "30"));
mListData.add(new Model("Potato Salad", "40"));
mListData.add(new Model("Pumpkin Pie", "60"));
mListData.add(new Model("Salisbury Steak", "70"));
adapter = new CustomListAdapter(this, R.layout.listrow, mListData);
listView.setAdapter(adapter);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action) {
startActivity(new Intent(MainActivity.this, NextActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
}public class CustomListAdapter extends ArrayAdapter<Model> {
private Context mContext;
int resource;
private ArrayList<Model> mListData = new ArrayList<Model>();
public CustomListAdapter(Context mContext, int resource, ArrayList<Model> mListData) {
super(mContext, resource, mListData);
this.resource = resource;
this.mContext = mContext;
this.mListData = mListData;
}
public void setListData(ArrayList<Model> mListData) {
this.mListData = mListData;
notifyDataSetChanged();
}
@Override
public int getCount() {
return super.getCount();
}
@Override
public View getView(final int position, View convertView, final ViewGroup parent) {
View v = convertView;
final ViewHolder holder;
if (v == null) {
holder = new ViewHolder();
LayoutInflater inflater = ((Activity) mContext).getLayoutInflater();
v = inflater.inflate(resource, parent, false);
holder.name = (TextView) v.findViewById(R.id.name);
holder.rate = (TextView) v.findViewById(R.id.rate);
holder.add = (Button) v.findViewById(R.id.add);
holder.remove = (Button) v.findViewById(R.id.remove);
v.setTag(holder);
} else {
holder = (ViewHolder) v.getTag();
}
final Model item = mListData.get(position);
holder.name.setText(item.getName());
holder.rate.setText(item.getRate());
holder.add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
SQLiteHandler db = new SQLiteHandler(getContext());
if(db.ifExists(item)){
Toast.makeText(getContext(), "Already Present", Toast.LENGTH_SHORT).show();
}else{
db.addItems(holder.name.getText().toString(), holder.rate.getText().toString());
Toast.makeText(getContext(), "Added", Toast.LENGTH_SHORT).show();
}
}
});
holder.remove.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
SQLiteHandler db = new SQLiteHandler(getContext());
db.deleteItem(item);
Toast.makeText(getContext(), "Removed", Toast.LENGTH_SHORT).show();
}
});
return v;
}
class ViewHolder {
TextView name;
TextView rate;
Button add;
Button remove;
}
}public class SQLiteHandler extends SQLiteOpenHelper {
\t private static final String TAG = SQLiteHandler.class.getSimpleName();
\t // All Static variables
\t // Database Version
\t private static final int DATABASE_VERSION = 1;
\t // Database Name
\t private static final String DATABASE_NAME = "android_api";
\t // Profile Settings table name
\t private static final String TABLE_SHOP = "shop";
\t // Profile Settings information names
\t private static final String KEY_ID = "id";
\t private static final String KEY_NAME = "name";
\t private static final String KEY_PRICE = "price";
\t public SQLiteHandler(Context context) {
\t \t super(context, DATABASE_NAME, null, DATABASE_VERSION);
\t }
\t // Creating Tables
\t @Override
\t public void onCreate(SQLiteDatabase db) {
\t \t String CREATE_PROF_TABLE = "CREATE TABLE " + TABLE_SHOP + "("+KEY_ID+" INTEGER PRIMARY KEY, "+KEY_NAME+" TEXT, "+KEY_PRICE+" TEXT" + ")";
\t \t db.execSQL(CREATE_PROF_TABLE);
\t \t Log.d(TAG, "Database tables created");
\t }
\t // Upgrading database
\t @Override
\t public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
\t \t // Drop older table if existed
\t \t db.execSQL("DROP TABLE IF EXISTS " + TABLE_SHOP);
\t \t // Create tables again
\t \t onCreate(db);
\t }
\t // Check before adding item if item already exist
\t SQLiteDatabase db = this.getWritableDatabase();
\t public boolean ifExists(Model model) {
\t \t Cursor cursor = null;
\t \t String checkQuery = "SELECT KEY_NAME FROM "+TABLE_SHOP+" WHERE KEY_NAME="+model.getName();
\t \t cursor= db.rawQuery(checkQuery,null);
\t \t boolean exists = (cursor.getCount() > 0);
\t \t cursor.close();
\t \t return exists;
\t }
// Add items to db
\t public void addItems(String name, String mobile){
\t \t SQLiteDatabase db = this.getWritableDatabase();
\t \t ContentValues values = new ContentValues();
\t \t values.put(KEY_NAME, name);
\t \t values.put(KEY_PRICE, mobile);
\t \t long id = db.insert(TABLE_SHOP, null, values); // insert to 1st row
\t \t db.close(); // Closing database connection
\t \t Log.d(TAG, "New products inserted into sqlite: " + id);
\t }
\t // Fetch all data
\t public ArrayList<HashMap<String, String>> getProfDetails()
{
ArrayList<HashMap<String, String>> array_list = new ArrayList<HashMap<String, String>>();
SQLiteDatabase db = this.getReadableDatabase();
String selectQuery = "SELECT * FROM " + TABLE_SHOP;
Cursor res = db.rawQuery(selectQuery, null);
res.moveToFirst();
while (res.isAfterLast() == false)
{
HashMap<String, String> hashmap= new HashMap<String, String>();
hashmap.put("name", res.getString(res.getColumnIndex(KEY_NAME)));
hashmap.put("price", res.getString(res.getColumnIndex(KEY_PRICE)));
array_list.add(hashmap);
res.moveToNext();
}
return array_list;
}
\t // Getting Sum of "price"
\t public int sumofPrice(){
\t \t SQLiteDatabase db = this.getReadableDatabase();
\t \t String selectQuery = "SELECT SUM(price) FROM " + TABLE_SHOP;
\t \t Cursor cur = db.rawQuery(selectQuery, null);
\t \t int total=0;
\t \t if(cur.moveToFirst())
\t \t {
\t \t \t total = cur.getInt(0);
\t \t }
\t \t return total;
\t }
\t // Delete single row
\t public void deleteItem(Model model) {
\t \t SQLiteDatabase db = this.getWritableDatabase();
\t \t db.delete(TABLE_SHOP, KEY_NAME + " = ?",new String[] { String.valueOf(model.getName()) });
\t \t db.close();
\t }
\t // Delete whole table
\t public void deleteTable() {
\t \t SQLiteDatabase db = this.getWritableDatabase();
\t \t // Delete All Rows
\t \t db.delete(TABLE_SHOP, null, null);
\t \t db.close();
\t \t Log.d(TAG, "Deleted all info from sqlite");
\t }
}
Отлично! Большое спасибо, @Vicky –
В любое время ... Наслаждайтесь своим кодом .... – Vickyexpert
Можете ли вы также помочь мне с другим запросом? @Vicky –