SELECT emp_num, years, SUM(salary) FROM sales
UNION ALL
SELECT emp_id, SUM(takehomepay)
FROM marketing
What error is present in the sample code above?
1. Queries being combined with the UNION ALL statement are
not allowed to have SELECT lists with a different number of
expressions.
2. You are not allowed to use aggregate functions within
two queries joined by a UNION ALL statement.
3. The UNION ALL statement incorrectly combines
the "years" result from the first query with the "SUM
(takehomepay)" result from the second query.
4. Unless the UNION ALL statement is replaced with a UNION
statement, the queries will return duplicates.
5. The "emp_id" column from the second query must be
renamed (or aliased) as "emp_num" so that it corresponds to
the column name from the first query. Otherwise, the
queries will not execute.
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Answer Posted / roopesh kumar
1. Queries being combined with the UNION ALL statement are
not allowed to have SELECT lists with a different number of
expressions.
Reason
Number of columns diff in both query.
| Is This Answer Correct ? | 7 Yes | 1 No |
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