Sqlite code should be executed only once

Question

I am developing a app using android C2DM. sqlite3 is my back-end. Everything is just working fine but am struck with an performance issue regarding sqlite3. so my question is 'can i place the database code somewhere where it will be executed only once i.e The dvm(dalvik vertiual machine) should execute the code pertaining to the db only once; during the successive run the dvm should not go thru the (db)code because the db had been created.

More specifically, my app send msg to all the phones which has my app. so when an app at the client end receives a msg, the dvm should not execute this code : SQLiteDatabase db;

    //use tat ref to open or create a table 
    db = openOrCreateDatabase( "/data/data/de.vogella.android.c2dm.simpleclient/app_database/file__0/0000000000000001.db", SQLiteDatabase.CREATE_IF_NECESSARY, null);

    try 
    {

        //initialsiging a query with all the table fields 
        final String CREATE_TABLE_CONTAIN = "CREATE TABLE IF NOT EXISTS tbl_Message4("
                + "id INTEGER PRIMARY KEY AUTOINCREMENT,"
                + "msg TEXT not null," 
                + "msg_time INTEGER not null,"
                + "msg_status INTEGER not null);";

        //execute the above query
        db.execSQL(CREATE_TABLE_CONTAIN);

Because everytime a msg comes this code ll be executed. So i want to avoid this, i guess i hv conveyed my message. Any help ll be much appreciated.

Thanks,

TheIlliterate

Did my answer help you out? If it did, you should accept it (click the check mark), if not, let us know so we can try to get the issue resolved. — Barak, May 14 '12 at 13:41

score 0 · Answer 1 · answered May 14 '12 at 06:10

0

What you are asking is the normal (and preferred) usage case.

Android has several classes and methods to do just that.

You basically create a helper class to manage the DB, it will have a class within it that extends SQLiteOpenHelper, in that you override the onCreate and onUpgrade methods to handle creating and upgrading your database. Then it is normal to create other methods (within the helper class but ouotside the SQLiteOpenHelper extended class) to handle all functions relating to the DB in the helper class as well, such as adding/deleting/updating records.

There are several examples and tutorials floating around. A good one is here.

Good luck

answered May 14 '12 at 06:10

Barak

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Hey, I went thru that tutorials but no where its mentioned that db code ll be executed once or every time a new message is received. – TheIlliterate May 15 '12 at 09:11
From the tutorial "In this class you need to override the onCreate() and onUpgrade() methods. onCreate() is called by the framework, if the database does not exists." Note that last bit: **If the database does not exist**. So it would create your DB only the one time. – Barak May 15 '12 at 12:12
Hi barak, i got that. But my question was; the dvm should go thru the db code only once and not every time a msg is received. – TheIlliterate May 16 '12 at 04:49
What? What do you mean? Why would it be run every time a message comes in? It only runs when you call it, and all it will do if you call it and the db exists is check that and then move on. It won;t run any code you don;t tell it to. – Barak May 16 '12 at 04:56

Sqlite code should be executed only once

1 Answers1