Join text from multiple rows based on common attribute in Excel

Question

I have a table of data in Excel that has a company ID in one column and a NAICS code in another column. Only one NAICS code can be entered per row. Within the table a company ID can appear more than once with the same or a different NAICS code.

In a separate table (tab) I have a list of unique company IDs with a separate column called NAICS codes. I want to create a formula that lists all NAICS codes belonging to a company in a string in that field.

Table 1

Company ID  NAICS Code
1   334
1   334
2   311
2   3231
2   311
3   311
3   311
3   336390
4   331110 
5   311821
6   311821
4   336411
3   3115

Table 2

Company ID  NAICS Codes
1   334
2   311, 3231
3   311, 336390
4   331110, 31110, 336411
5   311821
6   311821