Argthtjtr

Having a problem with displaying some records from a SQLite database in a List View in android studio. The code for displaying the list view is:

import android.app.DatePickerDialog;

import android.content.Intent;

import android.database.Cursor;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.Button;

import android.widget.DatePicker;

import android.widget.ListView;

import android.widget.SimpleCursorAdapter;

import android.widget.TextView;

import android.widget.Toast;



import java.util.Calendar;



public class PreviousHunts extends AppCompatActivity implements View.OnClickListener

{

    public TextView txtDate;

    public String strDate = "";

    public ListView lstView;



    @Override

    protected void onCreate(Bundle savedInstanceState)

    {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_previous_hunts);



        Button btnDateGet = findViewById(R.id.btnGetHunts);

        btnDateGet.setOnClickListener(this);



        Button btnHome = findViewById(R.id.btnHuntsHome);

        btnHome.setOnClickListener(this);



        txtDate = findViewById(R.id.txtDateThing);

        lstView = findViewById(R.id.lstView);

    }



    @Override

    public void onClick(View v)

    {

        switch (v.getId())

        {

            case R.id.btnGetHunts:

                getDate();

                break;

            case R.id.btnHuntsHome:

                goHome();

                break;

        }

    }



    private void getDate()

    {

        final Calendar c = Calendar.getInstance();

        final int Year = c.get(Calendar.YEAR);

        final int Month = c.get(Calendar.MONTH);

        final int Day = c.get(Calendar.DAY_OF_MONTH);



        DatePickerDialog datePickerDialog = new DatePickerDialog(this, new DatePickerDialog.OnDateSetListener()

        {

            @Override

            public void onDateSet(DatePicker view, int year, int month, int dayOfMonth)

            {

                String day = String.valueOf(dayOfMonth);

                String Smonth = String.valueOf(month + 1);

                String sYear = String.valueOf(year);



                txtDate.setText(day + "/" + Smonth + "/" + sYear);

                strDate = day + "/" + Smonth + "/" + sYear;

            }

        },Year, Month, Day);

        datePickerDialog.show();



        DatabaseHelper dbHelp = new DatabaseHelper(this);

        int huntID = dbHelp.getHuntIDforPastHunts(strDate);



        if (huntID == 0)

        {

            Toast.makeText(getApplicationContext(), "No Hunts on that day.", Toast.LENGTH_LONG).show();

        }

        else

        {

            LastPart(huntID);

        }

    }



    private void LastPart(int huntID)

    {

        DatabaseHelper dbHelp = new DatabaseHelper(this);

        Cursor cursor = dbHelp.getPastHuntLogs(huntID);



        cursor.moveToFirst();



        //SimpleCursorAdapter adapter = new SimpleCursorAdapter(this, lstView, cursor, new String {"BirdName", "SeenORShot", "BirdAge", "NumSeenORShot",

                //"OtherAnimalShotORClayShoot", "AnimalShotNameORTypeClaysShot"}, new int {100}, 0);



        //lstView.setAdapter(adapter);



        SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,

                R.layout.activity_previous_hunts,

                cursor,

                new String{"BirdName", "SeenORShot", "BirdAge", "NumSeenORShot", "OtherAnimalShotORClayShoot", "AnimalShotNameORTypeClaysShot"},

                new int{1, 2, 3, 4, 5, 6}

                ,0);



        lstView.setAdapter(adapter);

    }



    private void goHome()

    {

        Intent intent = new Intent(PreviousHunts.this, Home_Screen.class);

        startActivity(intent);

        finish();

    }

}



The database helper code is:



    public Cursor getPastHuntLogs(int huntID)

        {

            String query = "SELECT HuntID AS _id, BirdName, SeenORShot, BirdAge, NumSeenORShot, OtherAnimalShotORClayShoot, " +

                    "AnimalShotNameORTypeClaysShot FROM Log WHERE HuntID = " + "'huntID'";

            Cursor cursor = db.rawQuery(query, null);

            return cursor;

        }

XML for the listview, etc, is:

<?xml version="1.0" encoding="utf-8"?>

<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:app="http://schemas.android.com/apk/res-auto"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    tools:context=".PreviousHunts">



    <Button

        android:id="@+id/btnGetHunts"

        android:layout_width="150dp"

        android:layout_height="75dp"

        android:layout_marginStart="15dp"

        android:layout_marginTop="15dp"

        android:text="Select Date you wish to see hunts from"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toTopOf="parent" />



    <TextView

        android:id="@+id/txtDateThing"

        android:layout_width="wrap_content"

        android:layout_height="25dp"

        android:layout_marginEnd="100dp"

        android:layout_marginTop="45dp"

        android:text="Date"

        android:textSize="18sp"

        android:textStyle="bold"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintTop_toTopOf="parent" />



    <Button

        android:id="@+id/btnHuntsHome"

        android:layout_width="88dp"

        android:layout_height="50dp"

        android:layout_marginBottom="10dp"

        android:layout_marginEnd="100dp"

        android:layout_marginStart="100dp"

        android:text="Home"

        app:layout_constraintBottom_toBottomOf="parent"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintStart_toStartOf="parent" />



    <ListView

        android:id="@+id/lstView"

        android:layout_width="362dp"

        android:layout_height="342dp"

        android:layout_marginEnd="15dp"

        android:layout_marginStart="15dp"

        android:layout_marginTop="10dp"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toBottomOf="@+id/btnGetHunts" />

</android.support.constraint.ConstraintLayout>

The problem is that nothing happens. There are no errors in the run log and nothing is displaying. Help would be really appreciated.

Try adding database code after date selection.

Like this

private void getDate() {

    final Calendar c = Calendar.getInstance();

    final int Year = c.get(Calendar.YEAR);

    final int Month = c.get(Calendar.MONTH);

    final int Day = c.get(Calendar.DAY_OF_MONTH);



    DatePickerDialog datePickerDialog = new DatePickerDialog(this, new DatePickerDialog.OnDateSetListener()

    {

        @Override

        public void onDateSet(DatePicker view, int year, int month, int dayOfMonth)

        {

            String day = String.valueOf(dayOfMonth);

            String Smonth = String.valueOf(month + 1);

            String sYear = String.valueOf(year);



            txtDate.setText(day + "/" + Smonth + "/" + sYear);

            strDate = day + "/" + Smonth + "/" + sYear;



            // Try database code here

            DatabaseHelper dbHelp = new DatabaseHelper(this);

            int huntID = dbHelp.getHuntIDforPastHunts(strDate);



            if (huntID == 0)

            {

                Toast.makeText(getApplicationContext(), "No Hunts on that day.", Toast.LENGTH_LONG).show();

            }

            else

            {

                LastPart(huntID);

            }



        }

    },Year, Month, Day);

    datePickerDialog.show();

}

The main issue you have is that you aren't invoking the population of the list after you have retrieved the date. Rather that the list view is being populated before the date has been retrieved.

That is the code :-

    DatabaseHelper dbHelp = new DatabaseHelper(this);

    int huntID = dbHelp.getHuntIDforPastHunts(strDate);



    if (huntID == 0)

    {

        Toast.makeText(getApplicationContext(), "No Hunts on that day.", Toast.LENGTH_LONG).show();

    }

    else

    {

        LastPart(huntID);

    }

will execute before you have got the date, so no date no data extracted.

There are other issues, such as each time you hit the button you create a new adapter, when you should use one and refresh the list.

The following is how I'd suggest doing it and it's working code and has been tested. However, for the testing I've had to guess much of the DatabaseHelper as all that was available was the getPastHuntLogs method.

DatabaseHelper.java used was :-

public class DatabaseHelper extends SQLiteOpenHelper {



    /**

     * Suggest using 1 definitaion of table and column names and to ALWAYS use the constants

     */

    public static final String DBNAME = "hunter";

    public static final int DBVERSION = 1;

    public static final String TABLE_LOG = "Log";

    public static final String COL_TIMESTAMP = "timestamp";

    public static final String COl_LOG_HUNTID = "HuntID";

    public static final String COL_LOG_BIRDNAME = "BirdName";

    public static final String COL_LOG_SEENORSHOT = "SeenOrShot";

    public static final String COL_LOG_BIRDAGE = "BirdAge";

    public static final String COL_LOG_NUMSEENORSHOT = "NumSeenOrShot";

    public static final String COL_LOG_OTHERANIMALSSHOTORCLAYSHOOT = "OtherAnimalShotORClayShoot";

    public static final String COL_LOG_ANIMALSHORORTYPECLAYSHOOT = "AnimalShotNameORTypeClaysShot";



    SQLiteDatabase db;

    public DatabaseHelper(Context context) {

        super(context, DBNAME, null, DBVERSION);

        db = this.getWritableDatabase();

    }



    /**

     * Guestimate

     * @param db

     */

    @Override

    public void onCreate(SQLiteDatabase db) {



        String crt_log_tbl_sql = "CREATE TABLE IF NOT EXISTS " + TABLE_LOG + "(" +

                COl_LOG_HUNTID + " INTEGER PRIMARY KEY, " +

                COL_TIMESTAMP + " TEXT DEFAULT CURRENT_TIMESTAMP, " +

                COL_LOG_BIRDNAME + " TEXT, " +

                COL_LOG_SEENORSHOT + " TEXT, " +

                COL_LOG_BIRDAGE + " REAL," +

                COL_LOG_NUMSEENORSHOT + " INTEGER, " +

                COL_LOG_OTHERANIMALSSHOTORCLAYSHOOT + " TEXT," +

                COL_LOG_ANIMALSHORORTYPECLAYSHOOT + " TEXT " +

                ")";

        db.execSQL(crt_log_tbl_sql);

    }



    @Override

    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {



    }



    /**

     * Added so I could see the rows in the log

     */

    public void dumpLogTable() {

        Cursor csr = db.query(TABLE_LOG,null,null,null,null,null,null);

        DatabaseUtils.dumpCursor(csr);

        csr.close();

    }



    /**

     *  Guestimate. (note converts dates to YYYY-MM-DD format as stored )

     * @param strDate

     * @return

     */

    public int getHuntIDforPastHunts(String strDate) {

        int rv = 0;

        String datevalues = strDate.split("/");

        String srchdate = datevalues[2] + "-" + datevalues[1] + "-" + datevalues[0];

        String whereclause = "date(" + COL_TIMESTAMP + ")=?";

        String whereargs = new String{srchdate};

        Cursor csr = db.query(TABLE_LOG,null,whereclause,whereargs,null,null,null);

        if (csr.moveToFirst()) {

            rv = csr.getInt(csr.getColumnIndex(COl_LOG_HUNTID));

        }

        return rv;

    }



    /**

     *  ALlows some testing data to be added

     * @param birdname

     * @param seenorshot

     * @param birdage

     * @param numseenorshot

     * @param otheranimalshotorclayshoot

     * @param animalshotortypeclayshoot

     * @return

     */

    public long insertLog(String birdname, String seenorshot,double birdage, int numseenorshot, String otheranimalshotorclayshoot, String animalshotortypeclayshoot) {

        ContentValues cv = new ContentValues();

        cv.put(COL_LOG_BIRDNAME,birdname);

        cv.put(COL_LOG_SEENORSHOT,seenorshot);

        cv.put(COL_LOG_BIRDAGE,birdage);

        cv.put(COL_LOG_NUMSEENORSHOT,numseenorshot);

        cv.put(COL_LOG_OTHERANIMALSSHOTORCLAYSHOOT,otheranimalshotorclayshoot);

        cv.put(COL_LOG_ANIMALSHORORTYPECLAYSHOOT,animalshotortypeclayshoot);

        return db.insert(TABLE_LOG,null,cv);

    }



    /**

     * Very much as was

     * @param huntID

     * @return

     */

    public Cursor getPastHuntLogs(int huntID)

    {

        String query = "SELECT HuntID AS _id, BirdName, SeenORShot, BirdAge, NumSeenORShot, OtherAnimalShotORClayShoot, " +

                "AnimalShotNameORTypeClaysShot FROM Log " +

                "WHERE HuntID = " + String.valueOf(huntID) + //<<<<<<<<<< Changed

                ""; //<<<<<<<<<< ADDED so that WHERE...... can be commented out so select all

        return db.rawQuery(query, null); //<<<<<<<< returns cursor directly

    }

}

• refer to the comments

PreviousHunts.java

public class PreviousHunts extends AppCompatActivity implements View.OnClickListener {



    public TextView txtDate;

    public String strDate = "";

    public ListView lstView;

    SimpleCursorAdapter adapter; //<<<<<<<<<< ADDED

    DatabaseHelper dbHelp; //<<<<<<<<<< ADDED

    Cursor cursor; //<<<<<<<<<< ADDED



    @Override

    protected void onCreate(Bundle savedInstanceState)

    {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_previous_hunts);



        Button btnDateGet = findViewById(R.id.btnGetHunts);

        btnDateGet.setOnClickListener(this);



        Button btnHome = findViewById(R.id.btnHuntsHome);

        btnHome.setOnClickListener(this);



        txtDate = findViewById(R.id.txtDateThing);

        lstView = findViewById(R.id.lstView);

        dbHelp = new DatabaseHelper(this); //<<<<<<<<<< ADDED

        addSomeTestData(); //<<<<<<<<<< ADDDED



    }



    @Override

    public void onClick(View v)

    {

        switch (v.getId())

        {

            case R.id.btnGetHunts:

                getDate();

                break;

            case R.id.btnHuntsHome:

                goHome();

                break;

        }

    }



    private void getDate()

    {

        final Calendar c = Calendar.getInstance();

        final int Year = c.get(Calendar.YEAR);

        final int Month = c.get(Calendar.MONTH);

        final int Day = c.get(Calendar.DAY_OF_MONTH);



        DatePickerDialog datePickerDialog = new DatePickerDialog(this, new DatePickerDialog.OnDateSetListener()

        {

            @Override

            public void onDateSet(DatePicker view, int year, int month, int dayOfMonth)

            {

                String day = String.valueOf(dayOfMonth);

                String Smonth = String.valueOf(month + 1);

                String sYear = String.valueOf(year);



                txtDate.setText(day + "/" + Smonth + "/" + sYear);

                strDate = day + "/" + Smonth + "/" + sYear;

                displayHuntList(strDate); //<<<<<<<<<< CHANGED calls displayHuntList

            }

        },Year, Month, Day);

        datePickerDialog.show();

    }





    //<<<<<<<<<< NEW replaces last_hunt code



    public void displayHuntList(String strDate) {

        int huntID = dbHelp.getHuntIDforPastHunts(strDate);

        if (huntID < 1) {

            Toast.makeText(getApplicationContext(), "No Hunts on that day.", Toast.LENGTH_LONG).show();

        }

        cursor = dbHelp.getPastHuntLogs(huntID);

        //<<<<<<<<<< Only create a SimpleCursorAdapter instance once and reuse

        //<<<<<<<<<< NOTE!! Stock layout used for convenience >>>>>>>>>>

        if (adapter == null) {

            adapter = new SimpleCursorAdapter(this,

                    android.R.layout.simple_list_item_2,

                    cursor,

                    new String{DatabaseHelper.COL_LOG_BIRDNAME,

                            DatabaseHelper.COL_LOG_SEENORSHOT},

                    new int{android.R.id.text1,android.R.id.text2},

                    0

            );

            lstView.setAdapter(adapter);

        } else {

            // if called after the initial call just swap the cursor to refresh the list

            adapter.swapCursor(cursor);

        }

    }



    private void goHome()

    {

        //<<<<<<<<<< Commented body out so hitting HOME does nothing >>>>>>>>>>

        /*

        Intent intent = new Intent(PreviousHunts.this, Home_Screen.class);

        startActivity(intent);

        finish();

        */

    }



    /**

     * Added so some testing data is added (note 2 rows added each time App is run)

     * All rows have a timestamp as per the day the App is run (ok for testing)

     */

    private void  addSomeTestData() {

        dbHelp.insertLog("Pheasant","Seen",1.75,100,"N/A","N/A");

        dbHelp.insertLog("Grouse","SHOT",2.3,10,"NO","MAYBE");

        dbHelp.dumpLogTable();

    }

}

• Hopefully much of the code will be familiar, comments should help


• Note the list only ever shows 1 as selection is via the huntID (perhaps this is from another table, I guess so) (commenting out the WHERE line in the getPastHuntLogs method in DatabaseHelper.java will list all rows).

Result 1

When started (note I set the background of the ListView so it was easy to see):-

Result 2

After clicking Button and selecting current date :-

Actually went a less complicated but easier route after this. Simply made a long string which actually helped with later parts of the code in the long run. Thanks all for the help.