我有一个奇怪的问题.我从服务器获取数据并将其插入表中.插入后,我使用两个表之间的内部联接查询该数据.
@H_301_7@这是我的查询：
Select
F._id,F.id,F.logo,F.total_like,F.distance,F.store_name,F.mob_no_1,F.mob_no_2,F.mob_no_3,F.tel_no_1,F.tel_no_2,F.tel_no_3,F.description,R.total_record,R.total_page,R.current_page
from
FAVOURITE_STORES as F
INNER JOIN FAVOURITE_RECORDS as R on F.area_id = R.area_id
where
F.area_id = 2 and
R.area_id = 2
我在某些设备上将光标计数设置为1,在某些设备上,我将光标计数设置为零.即使表格中有数据.
public Cursor rawQuery(String sQuery,String[] selectionArgs) {
if(mDatabase == null) {
mDatabase = getWritableDatabase();
}
debug("Query "+sQuery);
return mDatabase.rawQuery(sQuery,selectionArgs);
}
游标类
public class ExampleCursorLoader extends CursorLoader {
private Activity mActivity;
private String msQuery;
private DBUtil mDbUtil;
private String[] mSelectionArgs;
public ExampleCursorLoader(Activity context,String query,String[] selectionArgs) {
super(context);
this.mActivity = context;
this.msQuery = query;
this.mSelectionArgs = selectionArgs;
this.mDbUtil = DBUtil.getInstance(mActivity.getApplicationContext());
}
public ExampleCursorLoader(Activity context,String query) {
this(context,query,null);
debug(query);
}
public Cursor loadInBackground() {
debug("Loading in Background");
Cursor cursor=null;
cursor = mDbUtil.rawQuery(msQuery,mSelectionArgs);
return cursor;
}
private void debug(String s) {
Log.v("Adapter ","Adapter " + s);
}
protected void onStartLoading() {
forceLoad();
debug("Started Loading");
}
protected void onStopLoading() {
super.onStopLoading();
}
}
这就是我所说的.
return new ExampleCursorLoader(mActivity,sQuery);
计数为1的设备是三星s3.三星是Grand.@H_301_7@有什么想法或建议吗？
解决方法
Device that gives count as 1 is Samsung s3. And zero is Samsung Grand.@H_301_7@ Have any thought or suggestion on this?
这种问题很难解释,因为它很可能不会抛出任何错误,只会显示不同的和不需要的结果.
您所能做的就是“改进查询”：
首先使用占位符而不是原始语句：
String query = "... where F.area_id = ? and R.area_id = ?";
String[] whereArgs = {"2","2"};
你也不需要使用AS子句,这足以说：
... from FAVOURITE_STORES F INNER JOIN FAVOURITE_RECORDS R on ...
