insert multiple values from one table to another

Question

I want to insert multiple rows with different value into one table from anthor table which have some device_id but it gives error this is my query

MySqlCommand cmd = new MySqlCommand("INSERT INTO ind_master(ind,device_id) SELECT ind FROM schedule_days WHERE device_id = '"+DBdevice_id+"','"+DBdevice_id+"'", con);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();

Answer 1

MySqlCommand cmd = new MySqlCommand("INSERT INTO ind_master(ind,device_id) SELECT ind,'"+DBdevice_id+"' FROM schedule_days WHERE device_id = '"+DBdevice_id+"'", con);

如果device_id为整数，则删除单引号''