日历事件查询的选择 [英] Selection of Calendar event query

问题描述

我试着读出从一个特定的日历事件。以下是code我尝试使用。但我不知道该如何选择了样子。我想使用日历ID为的选择。如果没有选择（空）读取所有的日历，但我只想之一。
查询看起来是这样的：

I try to read out events from a specific calendar. Following is the code I try to use. But I dont know how the selection has to look like. I want to use the calendar id for the selection. Without the selection (null) it reads out all calendars, but I just want one. A query looks like this:

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

选择：结果
过滤器宣称要返回的行，格式化为一个SQL WHERE子句（不包括WHERE本身）。传递null将返回给定的URI的所有行。

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.

这code是第一次尝试一个选择：

This code is the first try with a selection:

            Uri.Builder builder = Instances.CONTENT_URI.buildUpon();
            ContentUris.appendId(builder, now - DateUtils.DAY_IN_MILLIS);
            ContentUris.appendId(builder, now + DateUtils.DAY_IN_MILLIS);

            Cursor mCursor = null;
            final String[] projection = new String[]
            { CalendarContract.Events.TITLE, CalendarContract.Events.DTSTART, CalendarContract.Events.DTEND};

            mCursor = getContentResolver().query(
                builder.build(), projection, Instances._ID  + calendarID, null, null);
                mCursor.moveToFirst();  

这就是从上面code中的错误：

Thats the error from above code:

09-29 00:07:41.800: E/AndroidRuntime(14507): FATAL EXCEPTION: TweetCollectorTimer
09-29 00:07:41.800: E/AndroidRuntime(14507): android.database.sqlite.SQLiteException: no such column: _id3: , while compiling: SELECT title, dtstart, dtend FROM Instances INNER JOIN view_events AS Events ON (Instances.event_id=Events._id) WHERE (begin<=? AND end>=?) AND (_id3)
09-29 00:07:41.800: E/AndroidRuntime(14507):    at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:179)
09-29 00:07:41.800: E/AndroidRuntime(14507):    at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:135)
09-29 00:07:41.800: E/AndroidRuntime(14507):    at android.content.ContentProviderProxy.query(ContentProviderNative.java:358)
09-29 00:07:41.800: E/AndroidRuntime(14507):    at android.content.ContentResolver.query(ContentResolver.java:311)
09-29 00:07:41.800: E/AndroidRuntime(14507):    at de.ring.AppService$1.run(AppService.java:96)
09-29 00:07:41.800: E/AndroidRuntime(14507):    at java.util.Timer$TimerImpl.run(Timer.java:284)

编辑：

非常感谢，我把它改为：

Thanks a lot, I changes it to:

            mCursor =   getContentResolver().query(
                    builder.build(), projection, Instances.CALENDAR_ID  + " = ?",
                    new String[]{""+calendarID}, null);

其重要使用CALENDAR_ID而不仅仅是_ID。

Its important to use CALENDAR_ID and not just _ID.

推荐答案

让这个

  getContentResolver().query(
                    builder.build(), projection, Instances._ID  + "=?",
new String[]{""+calendarID}, null);

而不是这种

getContentResolver().query(
                builder.build(), projection,
 Instances._ID  + calendarID, null, null);

由于第三个参数需要选择字符串，你通过这个 Instances._ID + calendarID 这将是评估这种

SELECT ........ WHERE _id3; 

它的日历ID数追加到列名。

it append the number of the calendar id to the column name .

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