Android - What is the difference between getReadableDatabase () and getWritableDatabase ()?

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Android - What is the difference between getReadableDatabase () and getWritableDatabase ()?

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#1 by (4 votes)

3

I was able to enter information into the database by using the getReadableDatabase() method. Should not that be a mistake then? Should not be the getWritableDatabase() method?

private void savePet() {

        petDbHelper = new PetDbHelper(this);
        db = petDbHelper.getReadableDatabase();

        ContentValues values = new ContentValues();
        values.put(PetEntry.COLUMN_PET_NAME, mNameEditText.getText().toString());
        values.put(PetEntry.COLUMN_PET_BREED, mBreedEditText.getText().toString());
        values.put(PetEntry.COLUMN_PET_WEIGHT, mWeightEditText.getText().toString());
        values.put(PetEntry.COLUMN_PET_GENDER, mGender);

        long newRowID =
                db.insert(PetEntry.TABLE_NAME, null, values);

        /** Display rowID after finish */
        Toast.makeText(this, "New row added: " + newRowID, Toast.LENGTH_SHORT).show();

        /** Close Activity */
        finish();
    }

java android sqlite

asked by anonymous 24.02.2018 / 20:43

1 answer

Bhaskara beginner How to find out in what generation of garbage collector an object is allocated?

score 4 · Accepted Answer

According to the documentation , getReadableDatabase() :

Create and / or open a database. This will be the same thing returned by getWritableDatabase () unless some problem, such as a full disk, requires the database to be read-only

Translating:

Create or open a database. This will be the same object returned by getWritableDatabase() , unless a problem occurs, such as for example: if the disk is full the database opens in the read-only mode.

But looking at the getWritableDatabase () documentation, she says that if the disk is full, this method will return an error.

Summarizing : Both return the same object, so there is no error. But you should use getWritableDatabase() to save data to be able to deal better with any errors that may arise.