android - Retrieve blob from sqlite -

i retrieve blob database base on row position

i'm retrieving data sqlite database using cursor

 public cursor gettestdata(int index,string house)   {       try       {           string sql ="select * heroes position ="+ index +" , house='"+house+"'";                       cursor mcur = mdb.rawquery(sql, null);           if (mcur!=null)           {              mcur.movetofirst();           }           return mcur;       }       catch (sqlexception msqlexception)        {           log.e(tag, "gettestdata >>"+ msqlexception.tostring());           throw msqlexception;       }   } 

this returns me columns , can strings

cursor testdata = mdbhelper.gettestdata(pos,house);  string sname = utility.getcolumnvalue(testdata, "name"); string sadvance = utility.getcolumnvalue(testdata, "class"); 

this return column "name" , "class" value, how retrieve blob , show it.

byte[] img = utility.getimage(testdata, "image1"); 

this how im trying

public static byte[] getimage(cursor cur,string columnname){     return cur.getblob(cur.getcolumnindex(columnname)); } 

but getting null in img :(