SQL Inner Join
6.What type of join returns only common records from two tables?
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A. RIGHT JOIN
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B. INNER JOIN
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C. FULL JOIN
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D. LEFT JOIN
INNER JOIN
INNER JOIN
7.What is the output?
Table A Table B
id | name id | city
1 | John 1 | Delhi
2 | Mike 3 | Mumbai
SELECT A.name, B.city
FROM A INNER JOIN B ON A.id = B.id;
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A. John – Delhi
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B. Mike – Mumbai
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C. 2 rows
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D. No rows
John – Delhi
John – Delhi
8.If A.id has values 1, 2, 3 and B.id has 2, 3, 4 — how many rows in output?
SELECT * FROM A INNER JOIN B ON A.id = B.id;
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A. 1
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B. 2
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C. 3
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D. 4
2
2
9.If there are no matching customer IDs in customers, what will COUNT return?
SELECT COUNT(*)
FROM orders INNER JOIN customers ON orders.customer_id = customers.id;
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A. All orders
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B. 0
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C. NULL
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D. Error
0
0
10.If B has NULL values in id, what happens?
SELECT A.name, B.city
FROM A INNER JOIN B ON A.city_id = B.id;
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A. JOIN includes those rows
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B. JOIN skips them
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C. NULL shown in results
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D. Error
JOIN skips them
JOIN skips them