SQL Full Outer Join
6.FULL OUTER JOIN includes rows when:
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A. They match on key
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B. They do not match
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C. They either match or not
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D. Only if NULL
They either match or not
They either match or not
7.What happens when neither table has matching keys in FULL OUTER JOIN?
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A. Returns 0 rows
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B. All rows with NULLs from other table
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C. Only matching rows
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D. Only matching rows
All rows with NULLs from other table
All rows with NULLs from other table
8.Output for: If A: ids 1,2 and B: ids 3,4 — how many rows?
SELECT * FROM A FULL OUTER JOIN B ON A.id = B.id;
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A. 2
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B. 4
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C. 1
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D. 0
4
4
9.Which of the following is closest to FULL OUTER JOIN in MySQL?
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A. LEFT JOIN only
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B. RIGHT JOIN only
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C. LEFT JOIN + RIGHT JOIN + UNION
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D. INNER JOIN + CROSS JOIN
LEFT JOIN + RIGHT JOIN + UNION
LEFT JOIN + RIGHT JOIN + UNION