Android SQL - Check if whole row already exists in database

Question

I\'m trying to create a simple favorites application, where you can keep your favorites pages (from the web for example).

Let\'s say I have the following data in my

Answer 1

You can query to see if the a unique identifier is there in the database, in your case the title maybe the unique identifier of the row.

public boolean isEntry(int title){
    String queryString = "SELECT * FROM "+TABLE_NAME+" WHERE "+KEY_PROJECT_ID+" = "+"'"+project_id+"'";
    Cursor c = db.rawQuery(queryString, null);
    if(c.getCount() > 0){
        Log.i("CHECK", "true");
        return true;
    }
    else{ 
        return false;
    }
}

Here true would mean that there is a row like this, false would mean that there is no such entry.

Now let's say are about to insert an entry into the database. Even if the method returns a true value what you can do is you could compare the other two values as in your example. After that you could call a function to return a single row from the database, like

public String getCursor(int project_id){
    String queryString = "SELECT * FROM "+TABLE_NAME+" WHERE "+KEY_PROJECT_ID+" = "+"'"+project_id+"'";
    Cursor cursor = db.rawQuery(queryString, null);
    return cursor;
}

Once you have the function you can select the TAG and URL from it and see if it matches the one in your database.

Like this:

Cursor cursor = db.rawQuery(queryString, null);
String tag = "";
String url = "";

cursor.moveToFirst();
for (int i = 0; i < cursor.getCount(); i++) {
    like_state = cursor.getString(cursor.getColumnIndex(KEY_TAG));
    url = cursor.getString(cursor.getColumnIndex(KEY_URL));
    cursor.moveToNext();
}
cursor.close();

if(!ins_tag.equalsIgnoreCase(tag) || !ins_url.equalsIgnoreCase(url)) {
    //insert function here
}   

And as mentioned in the comments you should use the an AUTOINCREAMENT integer as a Primary Key.

Answer 2

There is a very graceful (imho) way to do this at the database level. Add this to your create table sql when you create your database:

 UNIQUE(TITLE, URL) ON CONFLICT REPLACE 

Then you can insert all you want without checking, it will either be added or updated if the row is already there.

Answer 3

You can check using cursor:

public boolean checkEvent(String title, String URL, String tag) 
{
    SQLiteDatabase db = this.getReadableDatabase();

    Cursor cursor = db.query(TABLES, 
            new String[] { KEY_TITLE,KEY_URL,KEY_TAG }, 
            KEY_TITLE + " = ? and "+ KEY_URL + " = ? and " + KEY_TAG + " = ?" , 
            new String[] {title,url,tag}, 
            null, null, null, null);

    if(cursor.moveToFirst())

     return true; //row exists
    else 
     return false;

}

Edit: Code now copy & paste ready