Multiple choice technology databases

How many columns are presented after executing this query: SELECT address1||','||address2||','||address2 "Adress" FROM employee;

  1. 1

  2. 2

  3. 3

  4. 0

  5. 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The concatenation operator (||) combines address1, commas, and address2 into a single string expression. Even though multiple columns are referenced, the entire expression is aliased as "Adress", resulting in exactly one output column.

AI explanation

To determine the number of columns presented after executing the given query, let's break down the query and analyze it step by step:

The query is: SELECT address1||','||address2||','||address2 "Adress" FROM employee;

Here, we are selecting three columns: address1, address2, and address2 (renamed as "Address" using the alias "Adress"). Each column is concatenated with a comma (',').

So, the query will produce three columns: address1, address2, and Address.

Therefore, the correct answer is C) 3.

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