Question

I want to display only those rows which has date equal to my String from getdate(string data) function, so I tried to change working function which was displaying all entries from database in a Listview with SELECT from … command but it didn’t work.
How can I get those events from my calendar?

My whole database code

Working corectly function:

public Cursor getAllContacts() 
{
    return database.query("calendar_events", new String[] {"_id", "event"}, 
     null, null, null, null, "date");
}

I wanted to change it to:

public Cursor getdate(String data){
    return database.rawQuery("SELECT event FROM calendar_events WHERE date = '" + data + "'", new String[] { "event"});
}

fragment of the function where I changed : getAllContacts( code was working corectly and displaying events from calendar in a List view, after clicking on it I can enter into all data from this database entry) to getdate(“2012-12-30”):

 private class GetContacts extends AsyncTask<Object, Object, Cursor> 
{
   DatabaseConnector dbConnector = new DatabaseConnector(DayPlan.this);

   @Override
   protected Cursor doInBackground(Object... params)
   {
      dbConnector.open();
      return dbConnector.getdate("2012-12-30"); 
   } 

   @Override
   protected void onPostExecute(Cursor result)
   {
      conAdapter.changeCursor(result); // set the adapter's Cursor
      dbConnector.close();
   } 
}

the whole code from this class:

Error I’m having:

01-02 14:32:13.828: E/AndroidRuntime(809): FATAL EXCEPTION: AsyncTask #1
01-02 14:32:13.828: E/AndroidRuntime(809): java.lang.RuntimeException: An error occured while executing doInBackground()
01-02 14:32:13.828: E/AndroidRuntime(809):  at android.os.AsyncTask$3.done(AsyncTask.java:299)
01-02 14:32:13.828: E/AndroidRuntime(809):  at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
01-02 14:32:13.828: E/AndroidRuntime(809):  at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
01-02 14:32:13.828: E/AndroidRuntime(809):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
01-02 14:32:13.828: E/AndroidRuntime(809):  at java.util.concurrent.FutureTask.run(FutureTask.java:137)
01-02 14:32:13.828: E/AndroidRuntime(809):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
01-02 14:32:13.828: E/AndroidRuntime(809):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
01-02 14:32:13.828: E/AndroidRuntime(809):  at java.lang.Thread.run(Thread.java:856)
01-02 14:32:13.828: E/AndroidRuntime(809): Caused by: java.lang.IllegalArgumentException: Cannot bind argument at index 2 because the index is out of range.  The statement has 0 parameters.
01-02 14:32:13.828: E/AndroidRuntime(809):  at android.database.sqlite.SQLiteProgram.bind(SQLiteProgram.java:212)
01-02 14:32:13.828: E/AndroidRuntime(809):  at android.database.sqlite.SQLiteProgram.bindString(SQLiteProgram.java:166)
01-02 14:32:13.828: E/AndroidRuntime(809):  at android.database.sqlite.SQLiteProgram.bindAllArgsAsStrings(SQLiteProgram.java:200)
01-02 14:32:13.828: E/AndroidRuntime(809):  at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:47)
01-02 14:32:13.828: E/AndroidRuntime(809):  at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
01-02 14:32:13.828: E/AndroidRuntime(809):  at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1253)
01-02 14:32:13.828: E/AndroidRuntime(809):  at com.examples.android.calendar.DatabaseConnector.getdate(DatabaseConnector.java:87)
01-02 14:32:13.828: E/AndroidRuntime(809):  at com.examples.android.calendar.DayPlan$GetContacts.doInBackground(DayPlan.java:70)
01-02 14:32:13.828: E/AndroidRuntime(809):  at com.examples.android.calendar.DayPlan$GetContacts.doInBackground(DayPlan.java:1)
01-02 14:32:13.828: E/AndroidRuntime(809):  at android.os.AsyncTask$2.call(AsyncTask.java:287)
01-02 14:32:13.828: E/AndroidRuntime(809):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
01-02 14:32:13.828: E/AndroidRuntime(809):  ... 4 more

How can I display my events with 2012-12-30 date only?

Answer 1

rawQuery is to use only with very particular queries, and only if you can’t do otherwise.

Your query is rather simple, and should be expressed this way :

return database.query("calendar_events", new String[] {"_id", "event"}, 
             "date = ?", new String[] { data }, null, null, "date");

Parameters are:

1. Table name
2. projection (the columns you want). _id is very important as CursorAdapters use it to find their way in your data. event is the column you are interested in
3. where clause. that’s your query. ? are replaced with args
4. whereArgs. used to replace your ?. Note that escaping and quotes are handled by sqlite entirely.
5. group by
6. having
7. order by