CODEWITHSUNDEEP
androidsqlite
Andy Zhai
Andy Zhai

Reputation: 65

the time of creating a SQLitedatabase in Android code

"SQLitedatabase operations（specially open or create database）need a lot of time to accomplish,so u should execute Database transaction Asynchronously".

I read this lines in "Professional Android 4 Application Development".

But I try ,It does't need lots of time. Who can tell me the truth?

The below is an example. Ths!

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.os.Bundle;
import android.app.Activity;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.view.Menu;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import db.Books;

public class MainActivity extends Activity
{
private TextView tvTest;
private static final String DB_COLUMN1 = "title";
private static final String DB_COLUMN2 = "value";
private static final String TABLE_NAME = "mytable";
private SQLiteDatabase db;

@Override
protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    tvTest = (TextView)findViewById(R.id.tv_test);

    System.out.println("Time1:"+ System.currentTimeMillis());
    // The book is a class that extends SQLiteOpenHelper
    Books books = new Books(this,"mybook",null,1);
    db = books.getReadableDatabase();
    System.out.println("Time2:"+ System.currentTimeMillis());
}
}

enter image description here

Upvotes: 2

Views: 79

Answers (2)

laalto
laalto

Reputation: 152817

For a simple database not involving much disk I/O it does not matter, as it is the likely case in your test program.

Opening a database per se does not take much I/O. However, opening the database will create it if it does not already exist.

Creating a database can take a lot of time, especially if there is a lot of I/O involved. Copying a prepopulated database from assets or running a lot of SQL queries to populate the database in code can take a lot of time.

It's a good practice to not do any potentially time-consuming I/O on the UI thread.

Upvotes: 1

Calvin
Calvin

Reputation: 634

Usually it does not take too much time that we need to create it Asynchronously. It is a good practice though. But my experience of 12 apps it does not necessarily need to be created in AsyncTask

Upvotes: 0

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