-- Some background

-- To query from a list:
select a, b, c from myTable where a IN (1, 2, 3)

-- To query from a correlated sub query
select a, b, c from myTable where a IN (select A.a from myOtherTable A)


-- An example of why correlated sub queries are bad if you don't use aliases
-- In the sub query, the DB doesn't know where to get the value of [a]
-- The name exists in both places
select a, b, c from myTable where a IN (select a from myOtherTable)


-- OK, Here's the question.  By accident my code created the following
select a, b, c from myTable where a IN (a)

-- I realized it returns all records because it compares the value of [a] in each row to itself.

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

We walk in the dark places no others will enter
We stand on the bridge and no one may pass