Append with only new fields from second table

[PshemekFLK]

Hello,

I have two tables which I want to append. Table 1 has  products repeated many times due to multiple items under each product. In the second table I have product fields with unique values and no item field.

I would like to append the tables resulting only in new products from table 2 being added to table 1.

Table 1

Product             Item

A                         1

B                         2

B                         3

C                         4

C                         5

Table 2

Product    

A                                                 

B                         

C                         

D

Desired result:

Product          Item

A                         1

B                         2

B                         3

C                         4

C                         5

D                        null

What I'm getting with an append: 

Product          Item

A                         1

B                         2

B                         3

C                         4

C                         5

A                     null

B                     null

C                     null

D                     null

"Removing Duplicates" will not work of course as it will not only get rid of null items but the relevant items as well. It seems like I'm missing an easy solution here.

[CNENFRNL · Accepted solution]

Use Anti-join to extract specific records,

let
    Tab1 = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclTSUTJUitWJVnICsozgLGMwyxnIMoGzTJViYwE=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Product = _t, Item = _t]),
    Tab2 = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WclSK1YlWcgKTzmDSRSk2FgA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Product = _t]),

    #"LeftAnti Join" = Table.NestedJoin(Tab2, "Product", Tab1, "Product", "t1", JoinKind.LeftAnti),
    Appended = Tab1 & Table.ExpandTableColumn(#"LeftAnti Join", "t1", {"Item"}, {"Item"})
in
    Appended