اضافة بيانات جديده الى جدول

{
string query="";
if (durtion.Equals("before"))
query="select * from TT where lecid like '"+lecid+"' and sh <="+sh+" and eh <= "+eh+" and eh > "+sh+" and day like '"+day+"'";
else if(durtion.Equals("after"))
query="select * from TT where lecid like '"+lecid+"' and sh >="+sh+" and sh < "+eh+" and eh >= "+eh+" and day like '"+day+"'";
else if(durtion.Equals("between"))
query="select * from TT where lecid like '"+lecid+"' and sh >"+sh+" and eh < "+eh+" and day like '"+day+"'";
else if(durtion.Equals("inner"))
query="select * from TT where lecid like '"+lecid+"' and sh ="+sh+" and eh = "+eh+" and day like '"+day+"'";

SqlCommand cmd=new SqlCommand(query,conn);
conn.Open();
SqlDataReader DR=cmd.ExecuteReader();
if (DR.Read())
{
conn.Close();
return true;
}
conn.Close();
return false;
}

private bool SelectLecture(int  sh,int eh,string lecid,string day,string durtion)