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Getting data from SQLite database into a list view. List view creates a new list space but does not show text

I am trying to get information from my SQLite database and display it as a list view in my android activity. I can see the entries in a text view in one activity but needed it in a list view in a separate activity, it creates a space where each entry is but it does not display text. When I create a new entry it creates a new space in the list but there is still no text. I was following tutorials but no one else seemed to have this issue in the comments. I get an error that says 'SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length' is this what is causing the problem?

This is my class file that creates the database

   package com.example.medicalpp;

import java.util.ArrayList;
import java.util.HashMap;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class Drugs {
    // set up how the database will look
    public static final String KEY_ROWID = "_id";
    public static final String KEY_NAME = "_drug_name";
    public static final String KEY_DOSE = "_drug_dose";
    public static final String KEY_TIME = "_drug_time";
    public static final String KEY_INFO = "_drug_info";

    private static final String DATABASE_NAME = "DrugList";
    private static final String DATABASE_TABLE = "drugsTable";
    private static final int DATABASE_VERSION = 1;

    private DbHelper ourHelper;
    private final Context ourContext;
    private SQLiteDatabase ourDatabase;


    private static class DbHelper extends SQLiteOpenHelper {
        public DbHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_VERSION);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            // Create the database
            db.execSQL("CREATE TABLE " + DATABASE_TABLE + " (" + KEY_ROWID
                    + " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_NAME
                    + " TEXT NOT NULL, " + KEY_DOSE + " TEXT NOT NULL, "
                    + KEY_TIME + " TEXT NOT NULL, " + KEY_INFO
                    + " TEXT NOT NULL)");
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // Drop table if updated
            db.execSQL("DROP TABLE IF EXISTS " + DATABASE_TABLE);
            onCreate(db);
        }
    }

    public Drugs(Context c) {
        ourContext = c;
    }

    public Drugs open() throws SQLException {
        ourHelper = new DbHelper(ourContext);
        ourDatabase = ourHelper.getWritableDatabase();
        return this;
    }

    public void close() {
        ourHelper.close();
    }


    public ArrayList<HashMap<String, String>> getAllDrugs(){
        ArrayList<HashMap<String, String>> drugArrayList = new ArrayList<HashMap<String, String>>();
        String [] columne = new String[] { KEY_ROWID, KEY_NAME, KEY_DOSE };
        Cursor cursor = ourDatabase.query(DATABASE_TABLE, columne, null, null, null,
                null, null);

        if(cursor.moveToFirst()){

            do{
                HashMap<String, String> drugMap = new HashMap<String, String>();
                drugMap.put("KEY_ROWID", cursor.getString(0));
                drugMap.put("KEY_NAME", cursor.getString(1));
                drugMap.put("KEY_DOSE", cursor.getString(2));

                drugArrayList.add(drugMap);

            } while(cursor.moveToNext());
        }
        return drugArrayList;
    }

}

This is my java class file

    package com.example.medicalpp;

import java.util.ArrayList;
import java.util.HashMap;

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;

public class AddNew extends ListActivity {

    Intent intent;
    TextView tvDrugID;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_add_new);
        Drugs drugName = new Drugs(this);
        drugName.open();
        ArrayList<HashMap<String, String>> drugList = drugName.getAllDrugs();


        if(drugList.size() != 0){
            ListView listview = getListView();
            listview.setOnItemClickListener(new OnItemClickListener(){

                @Override
                public void onItemClick(AdapterView<?> arg0, View view,
                        int arg2, long arg3) {

                    tvDrugID = (TextView) view.findViewById(R.id.tvDrugID);

                    String drugIDValue = tvDrugID.getText().toString();
                    Intent theIntent = new Intent("com.example.medicalpp.EDITDRUGS");
                    theIntent.putExtra("tvDrugID", drugIDValue);
                    startActivity(theIntent);
                }
            });         
            ListAdapter adapter = new SimpleAdapter(
                    AddNew.this, drugList, R.layout.item_layout, 
                    new String[] {"tvDrugID", "tvDrugName", "tvDrugDose"}, 
                    new int[] {R.id.tvDrugID, R.id.tvDrugName, R.id.tvDrugDose});

            setListAdapter(adapter);
        }
        drugName.close();

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.add_new, menu);
        return true;
    }

}

And this is the activity xml file

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".AddNew" >

    <TextView
        android:id="@+id/drugName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/choose" />

    <ListView
        android:id="@id/android:list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>

The xml for my list view

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/tvDrugID"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="20dp"
        android:layout_marginTop="16dp"
        android:visibility="gone"
         />

    <TextView
        android:id="@+id/tvDrugName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="20dp"
        android:layout_marginTop="16dp"
        android:text="@string/name"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <TextView
        android:id="@+id/tvDrugDose"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/tvDrugName"
        android:layout_alignBottom="@+id/tvDrugName"
        android:layout_marginLeft="20dp"
        android:layout_toRightOf="@+id/tvDrugName"
        android:text="@string/dose"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

In getAllDrugs() , didn't you mean:

HashMap<String, String> drugMap = new HashMap<String, String>();
drugMap.put("tvDrugID", cursor.getString(0));
drugMap.put("tvDrugName", cursor.getString(1));
drugMap.put("tvDrugDose", cursor.getString(2));

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