Sql Excel : LOOKUP: Looking Up Values in One Table in Another

The LOOKUP operator takes two inputs, a base table and a reference table, which
have a key in common. The reference table should have at most one row for each
key value. The LOOKUP operator appends one or more columns in the reference
table to the base table, based on matching key values. When there is no match,
LOOKUP just outputs NULL for the corresponding output columns.
It takes two parameters. The first describes the key and the second describes
which columns to append. Although this can also be accomplished with a JOIN,
the LOOKUP is intended to be simpler and more readable for this common
operation where no new rows are generated and no rows are filtered