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
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A Correct answer
Explanation

The || operator concatenates strings in SQL. The entire expression address1||','||address2||','||address2 is treated as a single column with the alias 'Adress'. No matter how many columns or literals you concatenate, the result is always one column in the output.

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