Error inserting data from many method return lists to a database in c#

I need help here with part of my code so here it is:

I have 6 methods as you can see below that parse incoming data and then returns it as a list, so my issue is to send that list data to my database table SerialNumber, each method of the lists is a separate field that will fill a database column.

So for example the parse material will fill the database materiallookupcode column and the same for the others.

Here is an image of the database table

Here is the code of all 5 methods that reads the data and then returns it and I need this data send to my database

private List<string> ParseMaterial()
        {
            var materialList = new List<string>();

            foreach (var material in _connection.GetBarcodeList())
            {
                materialList.Add(material.Substring(10, 5));
            }

            return materialList;
        }

        private List<string> ParseLot()
        {
            var lotList = new List<string>();
            var establishmentList = GetEstablishmentCode();

            foreach (var lot in _connection.GetBarcodeList())
            {
                if (establishmentList.Contains("038"))
                {
                    lotList.Add(lot.Substring(28, 6) + _lotEstablishment.LoganSport038Property);
                }
                if (establishmentList.Contains("072"))
                {
                    lotList.Add(lot.Substring(28, 6) + _lotEstablishment.LouisaCounty072Property);
                }
                if (establishmentList.Contains("086"))
                {
                    lotList.Add(lot.Substring(28, 6) + _lotEstablishment.Madison086Property);
                }
                if (establishmentList.Contains("089"))
                {
                    lotList.Add(lot.Substring(28, 6) + _lotEstablishment.Perry089Property);
                }
                if (establishmentList.Contains("069"))
                {
                    lotList.Add(lot.Substring(28, 6) + _lotEstablishment.StormLake069Property);
                }
                if (establishmentList.Contains("088"))
                {
                    lotList.Add(lot.Substring(28, 6) + _lotEstablishment.Waterloo088Property);
                }
                if (establishmentList.Contains("265"))
                {
                    lotList.Add(lot.Substring(28, 6) + _lotEstablishment.GoodLetsVille265Property);
                }
                if (establishmentList.Contains("087"))
                {
                    lotList.Add(lot.Substring(28, 6) + _lotEstablishment.CouncilBluffs087Property);
                }
                if (establishmentList.Contains("064"))
                {
                    lotList.Add(lot.Substring(28, 6) + _lotEstablishment.Sherman064Property);
                }

            }

            return lotList;
        }

        private List<string> ParseSerialNumber()
        {
            var serialNumberList = new List<string>();

            foreach (var serialNumber in _connection.GetBarcodeList())
            {
                serialNumberList.Add(serialNumber.Substring(36, 10));
            }

            return serialNumberList;
        }

        public List<string> ParseNetWeight()
        {
            var netWeightList = new List<string>();


            foreach (var netWeight in _connection.GetBarcodeList())
            {            
                netWeightList.Add(netWeight.Substring(22, 4));
            }

            return netWeightList;
        }

        public List<string> ParseGrossWeight()
        {
            var grossWeightList = new List<string>();

            foreach (var grossWeight in _connection.GetBarcodeList())
            {
                grossWeightList.Add(grossWeight.Substring(22, 4));
            }

            return grossWeightList;
        }

        public List<string> FullBarcode()
        {
            var receiveFullBarcodeList = new List<string>();

            foreach (var fullBarcode in _connection.GetBarcodeList())
            {
                receiveFullBarcodeList.Add(fullBarcode);
            }

            return receiveFullBarcodeList;
        }

        public List<string> GetEstablishmentCode()
        {
            var establishmentList = new List<string>();

            foreach (var establishmentCode in _connection.GetBarcodeList())
            {
                establishmentList.Add(establishmentCode.Substring(36, 3));
            }

            return establishmentList;
        }

The issue is here the button when clicking will read all 5 methods and send it to the database, I am sure the part where I making the list of variables to a string and the separator part is wrong so I need how is the correct way to add those list to each column of the database

    private async void btn_SubmitData_Click(object sender, EventArgs e)
              {
                 // parse list methodss
            var materialList = ParseMaterial();
            var lotList = ParseLot();
            var netWeightList = ParseNetWeight();
            var grossWeightList = ParseGrossWeight();
            var serialNumberList = ParseSerialNumber();
            var fullSerialNumberList = FullBarcode();

            var material = "";
            var lot = "";
            var net = "";
            var gross = "";
            var serial = "";
            var fullSerial = "";

            var currentUser = _currentUser.GetCurrentUsernameOnApp();
            var licensePlateId = GetLicensePlateIds();

            for (var i = 0; i < _connection.GetBarcodeList().Count; i++)
            {
                 material = materialList[i];
                 lot = lotList[i];
                 net = netWeightList[i];
                 gross = grossWeightList[i];
                 serial = serialNumberList[i];
                 fullSerial = fullSerialNumberList[i];
            }

            // database table and columns
            var serialNumbersInsert = new List<SerialNumber>
            {
                new SerialNumber
                {
                    SerialNumberLookupCode = serial,
                    NetWeight = Convert.ToDecimal(net) / 100,
                    GrossWeight = Convert.ToDecimal(gross) / 100,
                    LotLookupCode = lot,
                    MaterialLookupCode = material,
                    FullSerialNumberLookupCode = fullSerial,
                    CreatedSysDateTime = DateTime.Now,
                    ModifiedSysDateTime = DateTime.Now,
                    CreatedSysUser = currentUser,
                    ModifiedSysUser = currentUser,
                    LicensePlateId = licensePlateId
                }
            };

            // insert to the database
            foreach (var list in serialNumbersInsert)
            {
                _unitOfWork.SerialNumbers.Add(list);
            }
            await _unitOfWork.Complete();
}

Here is the SerialNumber domain class that represents a database table using a code first migration

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace BarcodeReceivingApp.Core.Domain
{
    // domain class, represents a database table in sql server using code 
    // first migration
    public class SerialNumber
    {
        public int Id { get; set; }
        public int LicensePlateId { get; set; }
        public string FullSerialNumberLookupCode { get; set; }
        public string SerialNumberLookupCode { get; set; }
        public decimal NetWeight { get; set; }
        public decimal GrossWeight { get; set; }
        public string LotLookupCode { get; set; }
        public string MaterialLookupCode { get; set; }
        public DateTime CreatedSysDateTime { get; set; }
        public DateTime ModifiedSysDateTime { get; set; }
        public string CreatedSysUser { get; set; }
        public string ModifiedSysUser { get; set; }

    }
}

I search other places but could not find a good solution so far, so any help is appreciate it.