Android

Question

我有一个 subquery sqlite :

SELECT BookDB.ArticleID,BookDB.Title, subquery.Title FROM BookDB, (SELECT 
MetaDataID,Title  FROM MetaDataDB  order by OrderView) subquery WHERE 
subquery.MetaDataID = BookDB.ArticleID;

这个 query 得到了我的结果（在编辑器 sqlite 中）但是我在 android 的 cursor 中看不到任何结果。

cursor = sql.rawQuery("SELECT BookDB.ArticleID,BookDB.Title, subquery.Title FROM BookDB, (SELECT 
MetaDataID,Title  FROM MetaDataDB  order by OrderView) subquery WHERE 
subquery.MetaDataID = BookDB.ArticleID;", null);
                    if (cursor != null) {
                        do {
                            cursor.moveToFirst();
                            String C = cursor.getString(cursor.getColumnIndex("BookDB.Title"));
                            Log.i("results",C);
                        } while (cursor.moveToNext());
                    }

注意：如何从这一行获得结果？

String C = cursor.getString(cursor.getColumnIndex("BookDB.Title"));

Answer 1

我更改了我的 Query 并且成功了：

cursor = sql.rawQuery("SELECT BookDB.ArticleID as ID,BookDB.Title as TITLE, subquery.Title as COMM FROM BookDB, (SELECT 
MetaDataID,Title  FROM MetaDataDB  order by OrderView) subquery WHERE 
subquery.MetaDataID = BookDB.ArticleID;", null);
                    if (cursor != null) {
                        do {
                            cursor.moveToFirst();
                            String C = cursor.getString(cursor.getColumnIndex("TITLE"));
                            Log.i("results",C);
                        } while (cursor.moveToNext());
                    }

立即获取结果。

Android - 从 android 的游标中的子查询获取结果？

Android - Get results from subquery in cursor of android?

sqlite

android-cursor

android-sqlite