Develop Reference

What kind of information can i find on android's Contacts Provider

I am developing an android application and I need to know all the information about phone contacts.
I developed a function to get the name and number of all the contacts, but I need all the information about particular contact such as email, date, favorite or not, image, social links if available.
I got id, name and number from following:
String id = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts._ID));
String name = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
String number = pCur.getString(pCur.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
I used ContactsContract.Contacts to get _ID and DISPLAY_NAME, but
ContactsContract.CommenDataKinds.Phone to get the NUMBER. Is it correct?
Please explain the difference between the two methods.
Is the _ID a unique ID for all the contacts?

After a long discussion with #pskink I finally found the solution to list all related information for each contact in the directory.
First of all, create a cursor:
Cursor cursor = cr.query(ContactsContract.Data.CONTENT_URI, null, null, null, null);
And after that, you can dumb the cursor to show all the informations and see each contact and keywords it needs to use, like (custom_ringtone, display_name, photo_uri, is_primary, ..) by using this line of code:
DatabaseUtils.dumpCursor(cursor);
Special thanks to #pskink

LAST_TIME_CONTACTED returns 0

I can get contact id and name from my contact list. But LAST_TIME_CONTACTED returns 0. How can I get LAST_TIME_CONTACTED correctly ?
My code:
ContentResolver cr = getContentResolver();
Cursor cur = cr.query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);
if (cur.getCount() > 0)
{
while (cur.moveToNext())
{
String id = cur.getString(cur.getColumnIndex(ContactsContract.Contacts._ID));
String name = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
String last = cur.getString(cur.getColumnIndex(ContactsContract.Contacts.LAST_TIME_CONTACTED));
}
}

By the looks of things this isn't properly implemented by all device manufacturers. As such it seems like an unreliable field to use unfortunately. Almost certainly the case if you're using a Samsung Galaxy device...
As a side note, I think it's stored as an integer so you might be better using getInt() but I doubt very much that that's the problem.

Like Ed Hinchliffe said, it seems to be an unreliable field. However, you might be able to store such a value yourself if that is acceptable for your use case.
If you use a BroadcastReceiver and a PhoneStateListener you might be able to pull it off.
You would simply need to use String.valueOf(currentDate.getTime()); and store the value somewhere.

How to use Data.HAS_PHONE_NUMBER

I am a little bit confuse about the how to use Data.HAS_PHONE_NUMBER.
I have inserted contacts along with some additional Data and I would like to retrieve some of those contacts.
If I'm running the following code eveything is fine:
Uri uri = Data.CONTENT_URI;
String[] projection = new String[]{Data.CONTACT_ID, Data.DISPLAY_NAME };
String selection = Data.DATA4+" = ?";
String[] selectionArgs = new String[] {MY_VALUE};
Cursor truContactCursor = mContext.getContentResolver().query(uri, projection, selection, selectionArgs, null);
Now, I would like to know if those contacts have a phone number so I added HAS_PHONE_NUMBER into the projection like this:
String[] projection = new String[]{Data.CONTACT_ID, Data.DISPLAY_NAME, Data.HAS_PHONE_NUMBER };
When running the query I got the following execption:
java.lang.IllegalArgumentException: Invalid column has_phone_number
Why can I not access to HAS_PHONE_NUMBER? There is no problem with Data.DISPLAY_NAME which is in the same table. How are we suppose to use Data.HAS_PHONE_NUMBER then?
Thanks for your answer

Use HAS_PHONE_NUMBER is used for checking whether an contact has at least one phone number.example:
ContentResolver cr = getContentResolver();　　
Cursor cursor = cr.query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);
if(cursor.getCount()>0){
while (cursor.moveToNext()) {
String id = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts._ID));id
String name = cursor.getString(cursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
if(cursor.getInt(cursor.getColumnIndex(ContactsContract.Contacts.HAS_PHONE_NUMBER))>0){
//Query phone here.
}
or add in projection:
String [] projection = {ContactsContract.Contacts._ID,
ContactsContract.Contacts.DISPLAY_NAME,
ContactsContract.Contacts.HAS_PHONE_NUMBER};

Add "Data.MIMETYPE=ContactsContract.CommonDataKinds.Phone.CONTENT_ITEM_TYPE" to the selection statement.
The result cursor will include only the rows which have a phone number.
Tip.
There is the case: several numbers in one contact.
If you want all the numbers to be queried, add "ContactsContract.Data.DATA1" (Which means phone number) to the projection statement.

I encountered this same problem, and the only other reference to the problem I have found is another stackoverflow question.
I am planning on writing my own ContentProvider to do the "join" through programmatic means. That is, do the original query against the Data.CONTENT_URI but without the Data.HAS_PHONE_NUMBER projection, and then requery the given contact for the actual value of Data.HAS_PHONE_NUMBER. This surely lacks the performance of an actual DB join (being an n+1-type of select), but will provide the desired/expected functionality. This extra processing could be made conditional upon the OS level in order to maintain the efficiency on correctly functioning OS versions.
Given yulistic's answer above and my own experience, it would appear to be a bug in some versions of Android that this implicit join is not done. My Android v2.3.7 phone crashes with the same error you receive when Data.HAS_PHONE_NUMBER is in the projection, whereas my Android v4.2.2 tablet does not crash.
I have entered an Android Bug against the issue:
https://code.google.com/p/android/issues/detail?id=54095
Rob

How to distinguish between Telephonenumber and Mobilephonenumber

I have the following problem:
I have a RawContactID and want to get every information about this contact. I run a query like this:
String selection = ContactsContract.RawContactsEntity.RAW_CONTACT_ID +" = ?";
String[] selectionArgs = new String[]{contacts[0].get(0)};
Cursor cursor = getContentResolver().query(ContactsContract.Data.CONTENT_URI, null, selection, selectionArgs, null);
After that I run the cursor through a lot of elseif-Statemens to distinguish betweene the different MIME-Types and read the informations. Works fine, besides that it is very much code only to read informations about one contact, but ok.
The problem is that the MIME-Type for Mobilephonenumber and Telephonenumber are the same (vnd.android.cursor.item/phone_v2)??
How can i distinguish between those to different informations?
Any hint is highly appreciated!

ContactsContract.CommonDataKinds.Phone will let you distinguish between the types. There is a long list of which TYPE_HOME and TYPE_MOBILE are just two.
The sdk reference also states
You can use all columns defined for ContactsContract.Data as well as the following aliases.

Android : Why NUMBER_KEY return the number in reverse order

I am trying to read the contact list using the following code:
ContentResolver cr = getContentResolver();
Cursor cur = cr.query(People.CONTENT_URI,null, null, null, null);
if (cur.getCount() > 0) {
while (cur.moveToNext())
{
String id = cur.getString(cur.getColumnIndex(People._ID));
Cursor personCur = cr.query(Contacts.Phones.CONTENT_URI,
null,
Contacts.Phones.PERSON_ID +"= ?"+ Contacts.Phones.NUMBER_KEY ,
new String[]{id}, null);
String phoneKey = "";
while (personCur.moveToNext()) {
phoneKey = personCur.getString(personCur.getColumnIndex(Contacts.Phones.NUMBER_KEY));
}
The problem is that phoneKey return in reverse order meaning if the phone number is 054-123-4567 the value is 7654321450
I could not find any documentation on this issue.
Any idea how to fix it? or is it the expected result?
thanks
-Z

Firstly, Contacts.Phones.NUMBER_KEY is deprecated.
Secondly, why do you need this value? This is not the phone number, but the "normalized" phone number.
If you want the phone number in the way you have your code, use Contacts.Phones.NUMBER
Anyways, I would suggest you not to use deprecated elements unless you are targeting older phones.
================
Phone numbers are stored in stripped reversed order for easier matching. It helps to use the LIKE operator in SQL.
For a normal SQL user, it might look same to use where NUMBER_KEY LIKE '%1234' and where NUMBER_KEY LIKE '4321%'.
But for the db engine, having the wildcard at the end is much easier (efficient) Efficiency is a major factor for incoming call caller id lookup.
BTW, you might have not noticed, most phones (not talking about android only) does not match the whole number for caller id lookup.
In all my Nokia phones I have a number saved, say its 016 12345678 (its not the real number) as Mr X
When I get phone call from another number 016 99345678, it shows Mr X is calling. It compares only last few digits!!!