Помогите починить ошибку при нажатии

Программа ругается на данный отрезок кода главной активности:

public void add_person(View view) {
        String name = etName.getText().toString().trim();
        String birthday = dataText.getText().toString().trim();
        String iin = etIIN.getText().toString().trim();
        String phone = etPhone.getText().toString().trim();
        String status = sStatus.getSelectedItem().toString();
        String vaccination = sVaccination.getSelectedItem().toString();
        String symptoms = etSymptoms.getText().toString().trim();
        String sickDay = sickDayText.getText().toString().trim();
        String cureDay = cureDayText.getText().toString().trim();
        if (isFilled(name, birthday, iin, phone, status, vaccination, symptoms, sickDay, cureDay)) {
            ContentValues contentValues = new ContentValues();
            contentValues.put(DataBASE.SickPeopleEntry.COLUMN_NAME, name);
            contentValues.put(DataBASE.SickPeopleEntry.COLUMN_BIRTHDAY, birthday);
            contentValues.put(DataBASE.SickPeopleEntry.COLUMN_IIN, iin);
            contentValues.put(DataBASE.SickPeopleEntry.COLUMN_PHONE, phone);
            contentValues.put(DataBASE.SickPeopleEntry.COLUMN_STATUS, status);
            contentValues.put(DataBASE.SickPeopleEntry.COLUMN_VACCINATION, vaccination);
            contentValues.put(DataBASE.SickPeopleEntry.COLUMN_SYMPTOMS, symptoms);
            contentValues.put(DataBASE.SickPeopleEntry.COLUMN_SICK_DAY, sickDay);
            contentValues.put(DataBASE.SickPeopleEntry.COLUMN_CURE_DAY, cureDay);
            database.insert(DataBASE.SickPeopleEntry.TABLE_NAME, null, contentValues);
            Intent intent = new Intent(this, CreateDB.class);
            startActivity(intent);
        } else {
            Toast.makeText(this, error, Toast.LENGTH_SHORT).show();
        }
    }
private boolean isFilled(String name, String birthday, String iin, String phone, String status, String vaccination, String symptoms, String sickDay, String cureDay){
        return !name.isEmpty() && !birthday.isEmpty() && !iin.isEmpty() && !phone.isEmpty() && !status.isEmpty() && !vaccination.isEmpty() && !symptoms.isEmpty() && !sickDay.isEmpty() && !cureDay.isEmpty();
    }

Ошибка выглядит следующим образом:

E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.coronanews, PID: 24119
    java.lang.IllegalStateException: Could not execute method for android:onClick
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:414)
        at android.view.View.performClick(View.java:6597)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119)
        at android.view.View.performClickInternal(View.java:6574)
        at android.view.View.access$3100(View.java:778)
        at android.view.View$PerformClick.run(View.java:25885)
        at android.os.Handler.handleCallback(Handler.java:873)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:193)
        at android.app.ActivityThread.main(ActivityThread.java:6669)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Method.invoke(Native Method)
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409)
        at android.view.View.performClick(View.java:6597) 
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119) 
        at android.view.View.performClickInternal(View.java:6574) 
        at android.view.View.access$3100(View.java:778) 
        at android.view.View$PerformClick.run(View.java:25885) 
        at android.os.Handler.handleCallback(Handler.java:873) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:193) 
        at android.app.ActivityThread.main(ActivityThread.java:6669) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858) 
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'long android.database.sqlite.SQLiteDatabase.insert(java.lang.String, java.lang.String, android.content.ContentValues)' on a null object reference
        at com.coronanews.AddToDB.add_person(AddToDB.java:96)
        at java.lang.reflect.Method.invoke(Native Method) 
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:409) 
        at android.view.View.performClick(View.java:6597) 
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119) 
        at android.view.View.performClickInternal(View.java:6574) 
        at android.view.View.access$3100(View.java:778) 
        at android.view.View$PerformClick.run(View.java:25885) 
        at android.os.Handler.handleCallback(Handler.java:873) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:193) 
        at android.app.ActivityThread.main(ActivityThread.java:6669) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)