Android开发与SQLite的：查询结果不应该是空的

Question

我有一个相当大的查询，当在android外部执行时返回数据，而在android中执行时没有返回任何内容。

• 我把这个查询分成几部分，确定工会没问题。
• 我尝试了一组具有相同行为的较小数据。
• 我测试过不同的硬件和API版本。
• 我使用带有常量值的rawQuery方法。 http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html#rawQuery(java.lang.String, java.lang.String[])

此查询是为了替换当前不支持的FULL OUTER JOIN。

SELECT IFNULL(stype, gtype) AS type, IFNULL(sdate, gdate) AS date, IFNULL(sroute, groute) AS route FROM (

SELECT sp.type AS stype, sp.date AS sdate, -1 AS gtype, gp.date AS gdate, sp.route AS sroute, gp.route AS groute 
FROM Sensor_Point AS sp LEFT JOIN GPS_Point AS gp ON gp._id IS NULL AND sp.sent=0 AND sp.route=gp.route AND sp.route=1 
UNION ALL 
SELECT sp.type AS stype, sp.date AS sdate, -1 AS gtype, gp.date AS gdate, sp.route AS sroute, gp.route AS groute 
FROM GPS_Point AS gp LEFT JOIN Sensor_Point AS sp ON sp._id IS NULL AND gp.sent=0 AND sp.route=gp.route AND gp.route=1 

) WHERE route=1 ORDER BY date ASC LIMIT 255 

任何提示将不胜感激。

更新：

看的像问题终于与查询参数，如果我这样设置：

String[] args = new String[3]; 
args[0] = args[1] = args[2] = "1"; 
Cursor data dataBase.rawQuery(SELECT_POINTS, args); 

它不工作，而直接硬编码值时，工作在查询中。

Cursor data = dataBase.rawQuery(SELECT_POINTS, null); 

Answer 1

在Android数据库API中，所有查询参数都是字符串。 （这是一个可怕的设计错误。）

您的查询对应于：

... AND sp.route='1' 

尝试将参数字符串转换回一批这样的：

... AND sp.route = CAST(? AS INT) 

或只是把数字直接放入查询字符串中。