Fill in blank columns with another table

[rmartin1]

Hello,

I have Table1 that includes IP that I created from various import. Table2 has a unique indentifier Column name Hostname and IP. Now Table2 has Hostname with some blank IP cells that I can find in Table4. How do I fill in the blanks in Table2 If I find the Hostname containing the IP in Table1. 

I shorten the IP for ease.  Blank means a blank cell. (Thank You)

Table1

Hostname	IP
Sun123	1
Mars123	2
Saturn12	3

Table2

Hostname	IP
Sun123	blank
Mars123	blank
Saturn12	blank
Venus1	7

[Vijay_A_Verma · Accepted solution]

Issue this statement where #"Changed Type" should be replaced with your previous step

Table.ReplaceValue(#"Changed Type",each [IP],each if [IP]=null or [IP]="" then try Table1{[Hostname=[Hostname]]}[IP] otherwise null else [IP],Replacer.ReplaceValue,{"IP"})

See the working here - Open a blank query - Home - Advanced Editor - Remove everything from there and paste the below code to test

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WCi7NMzQyVtJRUorViVbyTSwqRuIGJ5aUFgHlYfyw1LzSYkMgz1wpNhYA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Hostname = _t, IP = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Hostname", type text}, {"IP", Int64.Type}}),
    Custom1 = Table.ReplaceValue(#"Changed Type",each [IP],each if [IP]=null or [IP]="" then try Table1{[Hostname=[Hostname]]}[IP] otherwise null else [IP],Replacer.ReplaceValue,{"IP"})
in
    Custom1