Question

// My getBus Function 
Cursor getBus(String source, String dest)
 {
     SQLiteDatabase db=this.getReadableDatabase();
     Cursor cur=db.rawQuery("SELECT b.BusName FROM BusTable b, (SELECT Route , RBusName FROM RouteBusTable WHERE Route IN ("+source+")) b1, (SELECT Route , RBusName FROM RouteBusTable WHERE Route IN ("+dest+")) c WHERE b.BusName IN (b1.RBusName) AND b.BusName IN (c.RBusName)", new String [] {});

     return cur;
 }

// Retreiving it like this
Cursor a = dbHelper.getBus("1", "12");

    a.moveToFirst();
    while (!a.isAfterLast())
    {
        String Name = a.getString(0);
        Toast.makeText(AddEmployee.this, "Stops Are "+ Name , Toast.LENGTH_LONG).show();
        a.moveToNext();
    }

它会停止应用。我做错了什么？子查询或检索是否有任何错误？

Answer 1

首先尝试引用source和dest以'这样的符号：

"... WHERE Route IN (\'"+source+"\') ..."

如果问题在这里，那么你应该考虑如何在source和dest中使用多个值来避免这种情况。在您的特定情况下，您应该像source = "\'1\', \'2\'"一样正确地形成它，或者使用here

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android sqlite中的子查询，无法正常工作

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