How to query the data from Content Provider?

The applications access the data from the other applications content providers using the content resolver object. Content Resolver runs as a client object and allow the CRUD (Create, Retrieve,Update and Delete) operations.

Content Provider Provides an abstract layer to query the data as table and hide the internal repository of application data. The Content Providers automatically handles the inter-process communication.

Note : To access the applications content provider the client application must need to specify the permissions in manifest file.

The ContentResolver object has methods identical to the ContentProvider and when resolver calls a method the identical name method will be invoked in ContentProvider Object.

The ContentResolver object ha a query method to pass a request to the ContentProvider Object.

// Queries the user dictionary and returns results
mCursor = getContentResolver().query(
    UserDictionary.Words.CONTENT_URI,   // The content URI of the words table
    mProjection,                        // The columns to return for each row
    mSelectionClause                    // Selection criteria
    mSelectionArgs,                     // Selection criteria
    mSortOrder);                        // The sort order for the returned rows

See the argument list for the query method

query() argument	SELECT keyword/parameter	Description
Uri	FROM table_name	Uri defines the content provider table_name
projection	col,col,col,...	projection is an array of columns for select list
selection	WHERE col =value	selection specifies the filter criteria for selecting  rows.
selectionArgs
sortOrder	ORDER BY col,col,...	sortOrder specifies the order in which rows appear in the returned Cursor.