CODEWITHSUNDEEP
androidsqlite
ParagonTime
ParagonTime

Reputation: 145

How do I use one button to swap between adding and deleting data from an sqlite database?

I have an sqlite database that collects data from the user and can delete it as well. Here is it being created:

db.execSQL("CREATE TABLE " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, DATA TEXT UNIQUE) ");

Here's the code for the adding data and removing data

public boolean insertData(String data) {
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues cValues = new ContentValues();
    cValues.put(Col_2, data);
    long result = db.insert(TABLE_NAME, null, cValues);
    if (result == -1)
        return false;
    else
        return true;
}


 public boolean deleteData(String data){
    SQLiteDatabase db = this.getWritableDatabase();
    long result = db.delete(TABLE_NAME, "DATA = ?", new String[]{data});
    ContentValues cValues = new ContentValues();
    if (result == 0)
        return false;
    else
        return true;
}

Here is the java button im trying to use

public void changeData(){
    favBtn.setOnClickListener(
            new View.OnClickListener(){
                @Override
                    public void onClick(View v){
                       boolean isInserted = myDB.insertData(textView.getText().toString());

                    if(isInserted == true)
                        Toast.makeText(randomApp.this, "Added Data", Toast.LENGTH_LONG).show();

                    else
                        Toast.makeText(randomApp.this, "Data was deleted", Toast.LENGTH_LONG).show();
                        myDB.deleteData(textView.getText().toString());


                }
            }
    );
}

The issue is that when this button is clicked it adds data but then will not remove said data. It will just continue playing the "added data" toast and add said data to the database- there is a unique constraint with the data column but I'm not really sure what I'm doing wrong or missing as I understand it should not be added twice. It should remove the data if that is already added and vice versa.

Upvotes: 1

Views: 63

Answers (2)

Midhun MP
Midhun MP

Reputation: 107221

According to your code the delete data code will always execute. And the data you are inserting will immediately deleted, hence the unique constraint won't break ever. You didn't put any {} in your else case and it contains two statements; first one considered as the statement inside else and second one will be considered as a statement outside the if and else case. So for fixing this issue you need to put {} properly. (Personal opinion : Try to put {} in if and else cases even if there is only one statement)

You should change that to:

if(isInserted == true)
{
    Toast.makeText(randomApp.this, "Added Data", Toast.LENGTH_LONG).show();
}
else
{
    Toast.makeText(randomApp.this, "Data was deleted", Toast.LENGTH_LONG).show();
    myDB.deleteData(textView.getText().toString());
}

Upvotes: 1

cylon
cylon

Reputation: 733

You are calling myDB.insertData on every click first, for every insert it will return true, so isInserted will be true always, thats why do you add multiple times the same data. Try this: 

private isInserted = false;    
public void changeData(){
        favBtn.setOnClickListener(
                new View.OnClickListener(){
                    @Override
                        public void onClick(View v){

                        if(!isInserted){
                            Toast.makeText(randomApp.this, "Added Data", Toast.LENGTH_LONG).show();
                            myDB.insertData(textView.getText().toString());
                        }
                        else{
                            Toast.makeText(randomApp.this, "Data was deleted", Toast.LENGTH_LONG).show();
                            myDB.deleteData(textView.getText().toString());
                        }
                        isInserted = !isInserted;
                    }
                }
        );
    }

Upvotes: 1

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