command = "SELECT (clients.fam_k +' '+ clients.name_k) AS [fio], tur_head.tur_date, 
tur_feder.feder, tur_head.comment_th FROM tur_head, clients, 
tur_feder WHERE tur_head.id_k = clients.id_k AND tur_head.id_f = tur_feder.id_f " +
" AND clients.fam_k Like '%'+@fam_k+'%'" +
" AND [tur_head.tur_date] BETWEEN (@DB and @DE)" +
" AND tur_feder.feder Like '%'+@feder+'%'";
System.Data.OleDb.OleDbDataAdapter adapter = new System.Data.OleDb.OleDbDataAdapter(command, connection);

adapter.SelectCommand.Parameters.Add("@fam_k", System.Data.OleDb.OleDbType.Char).Value = fam_k;
adapter.SelectCommand.Parameters.Add("@feder", System.Data.OleDb.OleDbType.Char).Value = feder;

adapter.SelectCommand.Parameters.Add("@DB", System.Data.OleDb.OleDbType.Date).Value = dateTimePicker1.Value;
adapter.SelectCommand.Parameters.Add("@DE", System.Data.OleDb.OleDbType.Date).Value = dateTimePicker2.Value;

DataTable topics = new DataTable();
adapter.Fill(topics);
dataGridView1.DataSource = topics;