How to over come database not opened exception?

Question

I am implementing an app related to database.

So many times I am calling open and close database connection to insert, update and delete.

It is working fine.

But some times I am getting a database not opened exception in different situations.

How to solve these issues?

Please post log cat here when its not been able to open the database . We can't read app's mind :) — Muhammad Umar
– Muhammad Umar, Commented Sep 7, 2012 at 8:06
This will commonly occurs when 2 or more threads try to modify same table or data. Follow these design patterns androiddesignpatterns.com/2012/05/…. No need to open and close db for every DAO call. — Ganesh K
– Ganesh K, Commented Sep 7, 2012 at 8:13
A side advise always put code if possible, accept the answers and upvote. Also put research base questions. — Jigar Pandya
– Jigar Pandya, Commented Sep 7, 2012 at 9:40
thanq for u'r replay.if u don't mind please provide some sample related to above discription — kiran
– kiran, Commented Sep 7, 2012 at 9:49

Jigar Pandya · Accepted Answer · 2012-09-07 09:39:51Z

1

Well unless you put proper exception handling you would never know what causes this.

However a good idea is to adopt good ORM mapper for SQL Light with Android and this will improve your database interactions and exception handling and opening and closing it efficiently.

You can opt for SUGAR or ORMLight if you wish; In my opinion this should help you to fix your problem.

answered Sep 7, 2012 at 9:39

Jigar Pandya

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Comments

avepr · Accepted Answer · 2012-09-07 10:12:09Z

Based on the information you provided I can assume that the problem is in your business logic and nobody but you should be able to tell you the root cause. Without your code here, we won't be able to point you to exact place. One of the possible reasons can be that by your business logic you are trying to do some operation (insert, update whatever) on closed database.

You can do some workaround to try to ensure that your DB is always open when it is needed. If you implement database getter method with so called lazy initialization approach it will guarantee at least, that the DB is open when you need to access it.

Here is what I am talking about: 1. make a public method which supposed to return DB object:

public SQLiteDatabase getDB() {
    if ((mDataBase == null) || (!mDataBase.isOpen())) {
        // create or open your database using an OpenHelper
        mDataBase = SQLiteOpenHelper.getWritableDatabase();
    }
    return mDataBase;
}

Now, everywhere in your code use this method to access the DB instead of directly accessing a variable mDataBase.

Note that the code is just to give you an idea and not actually compilable. Still, I would recommend you to fix your business logic instead of using this workaround.

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