managedQuery & query

 

public final Cursor managedQuery (Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)

Wrapper around query(android.net.Uri, String[], String, String[], String) that gives the resulting Cursor to call startManagingCursor(Cursor) so that the activity will manage its lifecycle for you.

 

根据制定的Uri返回查询特定数据结果的Cursor，Activity会管理cursor对象的的生命周期。

Parameters

uri The URI of the content provider to query.             /*需要返回的资源列表*/projection List of columns to return.                                     /*表示那些数据（columns）需要返回*/selection SQL WHERE clause.                                              /*查询条件*/selectionArgs The arguments to selection, if any ?s are pesent   /**/sortOrder SQL ORDER BY clause.                                         /*排序*/   

Returns

• The Cursor that was returned by query().

/***********************************************************/

 

public final Cursor query (Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder)

Query the given URI, returning a Cursor over the result set.

Parameters

uri The URI, using the content:// scheme, for the content to retrieve.projection A list of which columns to return. Passing null will return all columns, which is discouraged to prevent reading data from storage that isn't going to be used.selection A filter declaring which rows to return, formatted as an SQL WHERE clause (excluding the WHERE itself). Passing null will return all rows for the given URI.selectionArgs You may include ?s in selection, which will be replaced by the values from selectionArgs, in the order that they appear in the selection. The values will be bound as Strings.sortOrder How to order the rows, formatted as an SQL ORDER BY clause (excluding the ORDER BY itself). Passing null will use the default sort order, which may be unordered.

Returns

• A Cursor object, which is positioned before the first entry, or null

See Also

• Cursor