Фильтр datagridview

command.CommandText = @"Select id_ob, data, tip, opisanie, fio, status, name from ob, sotr, otdel, tip 
                                            where ob.sotr_id=sotr.id_sotr AND ob.tip_id=tip.id_tip AND ob.otdel_id=otdel.id_ot 
                                            AND otdel.id_ot LIKE " + label6.Text + " AND ob.tip_id LIKE " + comboBox3.SelectedValue + " AND ob.sotr_id LIKE " + comboBox5.SelectedValue + ";";

using (SqlCommand command = connection.CreateCommand())
                {
                    connection.Open();
                    command.CommandText = @"Select id_ob, data, tip, opisanie, fio, status, name from ob, sotr, otdel, tip 
                                            where ob.sotr_id=sotr.id_sotr AND ob.tip_id=tip.id_tip AND ob.otdel_id=otdel.id_ot 
                                            AND otdel.id_ot LIKE " + label6.Text + " AND ob.tip_id LIKE " + comboBox3.SelectedValue + " AND ob.sotr_id LIKE " + comboBox5.SelectedValue + ";";
                    var table = new DataTable();
                    table.Load(command.ExecuteReader());
                    dataGridView1.DataSource = table;//создаем привязку
                    connection.Close();
                    
                }

using (SqlCommand command = connection.CreateCommand())
                {
                    command.CommandText = "Select id_ot, name from otdel;";
 
                    var table = new DataTable();
                    table.Load(command.ExecuteReader());
                    comboBox2.DataSource = table;
                    comboBox2.ValueMember = "id_ot";
                    comboBox2.DisplayMember = "name";
                }

source1.Filter = "tip = '" + comboBox3.Text + "'AND fio = '"+ comboBox5.Text +"'";

string [] filter = new string [3];
if(comboBox1.Text =="") filter[0] ="";
else filter[0] = "tip = '"+comboBox1.Text;
 
if(comboBox2.Text =="") filter[1] ="";
else 
{
filter[1] = "fio = '"+comboBox2.Text;
if(filter[0] !="" )filter[0]+=" and ";
}
...
 
source1.Filter = filter[0] +filter[1] ...;