??
You dont know SQL, am i right? It sounds as if you are looking for an easy SELECT statement, but unfortunately your description is very poor and its impossible to understand, what you are looking for finally?! What exactly do you mean by " I have an excel file with the column SKU and I need to fill the data for every SKU"? What is meant by "fill the data"??
SQL works with tables (Excel also does) and the idea of SQL is tables, tables, tables. Create any table from another table(s).
Example: You have table with 3 columns. First Columns is an id (an uniq number, usually the primary key), second columns is familyname (like "Miller"),the third columns is called SKU (i have NO idea, what you mean by SKU) and it contains a SKU (whatever it is). The table is called "mytable" for example. Issue this simple SQL statement:
SELECT familiyname, SKU from mytable;
This creates an table which contains familiyname and SKU for all entries of your table. Not very sophisticated and you simply dropped the id, not more.
A more sophisticated example: same table as above, we issue this command:
SELECT familyname, SKU from mytable WHERE familiyname = "Miller";
This results in table, where ALL familiynames are "Miller" and also contains their SKU.
This is a super simple example, SQL is an extremely powefull language and far far superior to the simple vlookup from Excel.