Câu hỏi gốc môn DBI202

524 câu gốc, sắp theo số đề từng chứa câu đó.

20 kết quả phù hợp nhất

When we apply set operators (UNION, INTERSECT, EXCEPT) to two relations R and S, which conditions on R and S must be satisfied?

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Which of the followings is true?

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What does (FALSE AND NULL) return?

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Let R(ABCD) be a relation with functional dependencies {A -> B, C -> B, B -> D} What is the key for R (choose one)

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Given the relation schema $R(A,B,C,D)$ and functional dependencies $F = \{A \to C,\ D \to B\}$. Which functional dependency/ies can cause a violation of second normal form (2NF)?

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Given a $R(A,B,C,D)$ with the following FDs: $AB \to D$ $BC \to A$ $AD \to B$ $CD \to B$ $AD \to C$ Choose a correct statement about R:

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Except for _____, aggregate functions ignore null values.

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What SQL keyword can be used to return data from two non-related tables as a combined set of rows?

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What is the wildcards used for pattern matching?

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What is the difference between the WHERE and HAVING SQL clauses?

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The __________ set operator combines all tuples from two relations excluding duplicates.

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What is a relation instance?

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The functional dependency $A \to B$ for relation schema $R(A,B,C,D)$ implies that

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Choose the correct answer about FK:

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A _____ is a relation name, together with the attributes of that relation.

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Look at the following tables and then choose the correct statement. ARTISTS | Artist_id | Artist_Name | | :--- | :--- | | 1 | Bono | | 2 | Cher | ALBUM | Artist_id | Album_name | | :--- | :--- | | 3 | Eat the rich |

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Which is the subset of SQL commands used to manipulate Database structures, including tables?

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Which of the following statements is the most correct?

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When joining 2 relations, if we want to display all the records in that 2 relations, we must use:

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A tuple which fails to participate in a join is called:

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Câu hỏi gốc môn DBI202

When we apply set operators (UNION, INTERSECT, EXCEPT) to two relations R and S, which conditions on R and S must be satisfied?

Which of the followings is true?

What does (FALSE AND NULL) return?

Let R(ABCD) be a relation with functional dependencies {A -> B, C -> B, B -> D} What is the key for R (choose one)

Given the relation schema $R(A,B,C,D)$ and functional dependencies $F = \{A \to C,\ D \to B\}$. Which functional dependency/ies can cause a violation of second normal form (2NF)?

Given a $R(A,B,C,D)$ with the following FDs: $AB \to D$ $BC \to A$ $AD \to B$ $CD \to B$ $AD \to C$ Choose a correct statement about R:

Except for _____, aggregate functions ignore null values.

What SQL keyword can be used to return data from two non-related tables as a combined set of rows?

What is the wildcards used for pattern matching?

What is the difference between the WHERE and HAVING SQL clauses?

The __________ set operator combines all tuples from two relations excluding duplicates.

What is a relation instance?

The functional dependency $A \to B$ for relation schema $R(A,B,C,D)$ implies that

Choose the correct answer about FK:

A _____ is a relation name, together with the attributes of that relation.

Look at the following tables and then choose the correct statement. ARTISTS | Artist_id | Artist_Name | | :--- | :--- | | 1 | Bono | | 2 | Cher | ALBUM | Artist_id | Album_name | | :--- | :--- | | 3 | Eat the rich |

Which is the subset of SQL commands used to manipulate Database structures, including tables?

Which of the following statements is the most correct?

When joining 2 relations, if we want to display all the records in that 2 relations, we must use:

A tuple which fails to participate in a join is called: