sqlite 查询不工作 android

Question

这些是旋转器的方法

 mSpinnerModel.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                @Override
                public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                    selectedModel = parent.getItemAtPosition(position).toString();


                    Toast.makeText(parent.getContext(), "Selected Model: " + selectedModel, Toast.LENGTH_LONG).show();

                    String sp1 = String.valueOf(mSpinnerModel.getSelectedItem());
                    if (sp1.contentEquals("College1")) {
                        List<String> list = new ArrayList<String>();
                        list.add("MAHARANI UNIVERSITY ");
                        //list.add("MANIPAL ");
                      //  list.add("ITM UNIVERSITY ");
                       // list.add("UNIVERSITY1");
                        // list.add("MAHARANI UNIVERSTY");


                        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_item, list);
                        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                        dataAdapter.notifyDataSetChanged();


                        // selectedMake = parent.getItemAtPosition(position).toString();

                        mSpinnerMake.setAdapter(dataAdapter);
                    }

                    if (sp1.contentEquals("College2")) {
                        List<String> list1 = new ArrayList<String>();
                        list1.add("ITM UNIVERSITY");
                        //list1.add("UNIVERSITY2");
                       // list1.add("UNIVERSITY3");

                      //  selectedMake = parent.getItemAtPosition(position).toString();


                        ArrayAdapter<String> dataAdapter2 = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_dropdown_item, list1);
                        dataAdapter2.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                        dataAdapter2.notifyDataSetChanged();
                        mSpinnerMake.setAdapter(dataAdapter2);
                    }


                    if (sp1.contentEquals("College3")) {
                        List<String> list = new ArrayList<String>();
                        list.add("MANIPAL ");
                        //list.add("UNIVERSITY4");
                        //list.add("UNIVERSITY5");


                        ArrayAdapter<String> dataAdapter3 = new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_dropdown_item, list);
                        dataAdapter3.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                        dataAdapter3.notifyDataSetChanged();
                        mSpinnerMake.setAdapter(dataAdapter3);
                       // selectedMake = parent.getItemAtPosition(position).toString();
                    }


                }

                @Override
                public void onNothingSelected(AdapterView<?> parent) {

                }
            });

    mSpinnerMake.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener(){

        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
            selectedMake = parent.getItemAtPosition(position).toString();

        }

        @Override
        public void onNothingSelected(AdapterView<?> adapterView) {

        }
    });

            mSpinnerYear.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                @Override
                public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                    selectedYear = parent.getItemAtPosition(position).toString();
                    // Showing selected spinner item
                    Toast.makeText(parent.getContext(), "Selected Year: " + selectedYear, Toast.LENGTH_LONG).show();
                }

                @Override
                public void onNothingSelected(AdapterView<?> parent) {

                }
            });

            mButtonShow.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    String eligibleBattery=fetchEligibleBattery(mSqLiteDatabase);
                    mTextViewResult.setText(eligibleBattery);
                }
            });

        }

这是获取数据的数据和查询方法，但它不起作用。当我 select 微调器中的数据显示在 logcat 但它没有获取数据时，下面的查询无法正常工作，请帮助。

 private String fetchEligibleBattery(SQLiteDatabase db) {

        String battery="";
        String SELECT_BATTERY_QUERY = "SELECT "+ DatabaseConstants.KEY_BATTERY+" FROM " + DatabaseConstants.TABLE_CAR_DETAILS + " WHERE " + DatabaseConstants.KEY_CAR_MAKE + " ='" +selectedMake +
                "' AND "+ DatabaseConstants.KEY_CAR_MODEL +" = '"+ selectedModel+ "' AND "+ DatabaseConstants.KEY_CAR_YEAR+"= '"+selectedYear +"' ;";
        Log.d("Database", "Battery Select Query : " + SELECT_BATTERY_QUERY);
        Cursor cursor = db.rawQuery(SELECT_BATTERY_QUERY, null);
        try {
            if (cursor.moveToFirst()) {
                battery=cursor.getString(cursor.getColumnIndex(DatabaseConstants.KEY_BATTERY));
            }
        } catch (Exception e) {
            Log.d("Database", "Error while trying to get icons from database");
        } finally {
            if (cursor != null && !cursor.isClosed()) {
                cursor.close();
            }
        }
        return battery;
    }

    public void fetchDataFromDBForSpinners(SQLiteDatabase db) {


        String SELECT_MODELS_QUERY = "SELECT * FROM " + DatabaseConstants.TABLE_CAR_DETAILS + ";";

        String model, make, year;
        Cursor cursor = db.rawQuery(SELECT_MODELS_QUERY, null);
        try {
            if (cursor.moveToFirst()) {
                do {
                    model = cursor.getString(cursor.getColumnIndex(DatabaseConstants.KEY_CAR_MODEL));
                    make = cursor.getString(cursor.getColumnIndex(DatabaseConstants.KEY_CAR_MAKE));
                    year = cursor.getString(cursor.getColumnIndex(DatabaseConstants.KEY_CAR_YEAR));

                    models.add(model);
                     makes.add(make);
                    years.add(year);

                } while (cursor.moveToNext());
            }
        } catch (Exception e) {
            Log.d("DATABASE", "Error while trying to get events from database");
        } finally {
            if (cursor != null && !cursor.isClosed()) {
                cursor.close();
            }
        }

Answer 1

此查询错误请仔细查看我的固定码

String SELECT_BATTERY_QUERY = "SELECT "+ DatabaseConstants.KEY_BATTERY+" FROM " + DatabaseConstants.TABLE_CAR_DETAILS + " WHERE " + DatabaseConstants.KEY_CAR_MAKE + " = " +selectedMake +" AND "+ DatabaseConstants.KEY_CAR_MODEL +" = "+ selectedModel+ " AND "+ DatabaseConstants.KEY_CAR_YEAR+"= "+selectedYear ";

sqlite 查询不工作 android

sqlite query not working android

sqlite

android

android-spinner