Android call record deduplication Query Method

Recently, we have been studying the de-duplication of call record query data. We have been studying the getcontentresolver (). query method and made a little research on several parameters.

The method for removing the call record is found. You can use distinct (number) as distinct_number to retrieve only one column of data,

Cursor mcalllogcursor = getcontentresolver (). Query (calllog. CILS. content_uri, -------------- URI

New String [] {"max (date) as max_date", calllog. CILS. Number, calllog. CILS. Duration, calllog. CILS. Type}, ---------------- projection

"1 = 1) group by (number", ---------------- Selection

Null, ----------------- selectionarg

Calllog. CILS. default_sort_order); -------------- sortorder

The preceding statement is restored to an SQL statement, as shown in the following sentence.

Select max (date) as max_date, number, duration, type from callwhere (1 = 1) group by (number) order by date DESC

Implements the call record deduplication and query function (deduplication removes the call record before the specified time)

I personally understand SQL statement execution. The Select data selects max data from the table's Grop.