Tag: programming languages

Questions Related to programming languages

Which one is a system privilege?

technology programming languages

  1. SELECT

  2. EXECUTE

  3. ALTER TABLE

  4. CREATE TABLE

  5. DELETE

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Correct Option: D

Which functions are available in SQL?
technology programming languages

  1. string and date

  2. character and numeric

  3. integer and conversion

  4. calendar and date

  5. date and conversion

  6. translation and date

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Correct Option: B,E

Which three are true?
technology programming languages

  1. A MERGE statement is used to merge the data of one table with data from another.

  2. A MERGE statement can be used to update existing rows in a table.

  3. A MERGE statement replaces the data of one table with that of another.

  4. A MERGE statement can be used to insert new rows into a table.

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Correct Option: A,C,D

Which statements are true about constraints?

technology programming languages

  1. The UNIQUE constraint does not permit a null value for the column.

  2. The PRIMARY KEY and FOREIGN KEY constraints create a UNIQUE index.

  3. The NOT NULL constraint ensures that null values are not permitted for the column.

  4. A UNIQUE index gets created for columns with PRIMARY KEY and UNIQUE constraints.

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Correct Option: A,C

Which statements about subqueries are true?

technology programming languages

  1. A subquery should retrieve only one row.

  2. A subquery can retrieve zero or more rows.

  3. Subqueries CANNOT be nested by more than two levels.

  4. A subquery can be used only in SQL query statements.

  5. A subquery CANNOT be used in an SQL query statement that uses group functions.

  6. When a subquery is used with an inequality comparison operator in the outer SQL statement,

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Correct Option: B,F

Which view should a user query to display the columns associated with the constraints on a table owned by the user?
technology programming languages

  1. USER_CONSTRAINTS

  2. USER_OBJECTS

  3. ALL_CONSTRAINTS

  4. USER_CONS_COLUMNS

  5. USER_COLUMNS

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Correct Option: D

The user Alice wants to grant all users query privileges on her DEPT table. Which SQL statement accomplishes this?

technology programming languages

  1. GRANT select ON dept TO ALL_USERS;

  2. GRANT select ON dept TO ALL;

  3. GRANT QUERY ON dept TO ALL_USERS

  4. GRANT select ON dept TO PUBLIC;

  5. GRANT QUERY ON dept TO PUBLIC;

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Correct Option: D

Which constraint can be defined only at the column level?

technology programming languages

  1. UNIQUE

  2. NOT NULL

  3. CHECK

  4. PRIMARY KEY

  5. FOREIGN KEY

Show answer
Correct Option: B

AI Explanation

To answer this question, you need to understand the different types of constraints that can be defined in a database.

Option A) UNIQUE - This option is incorrect because the UNIQUE constraint can be defined at both the column level and the table level. It ensures that the values in a specific column or combination of columns are unique.

Option B) NOT NULL - This option is correct because the NOT NULL constraint can only be defined at the column level. It ensures that a column must have a value and cannot be left empty or null.

Option C) CHECK - This option is incorrect because the CHECK constraint can be defined at both the column level and the table level. It allows you to specify a condition that must be satisfied for the data in a column.

Option D) PRIMARY KEY - This option is incorrect because the PRIMARY KEY constraint can be defined at both the column level and the table level. It uniquely identifies each row in a table and can be defined on one or more columns.

Option E) FOREIGN KEY - This option is incorrect because the FOREIGN KEY constraint can be defined at both the column level and the table level. It establishes a relationship between two tables based on a common column.

The correct answer is B) NOT NULL. This option is correct because the NOT NULL constraint can only be defined at the column level, ensuring that the column must have a value and cannot be null.

In which cases would you use an outer join?

technology programming languages

  1. The tables being joined have NOT NULL columns.

  2. The tables being joined have only matched data.

  3. The columns being joined have NULL values.

  4. The tables being joined have only unmatched data.

  5. The tables being joined have both matched and unmatched data.

  6. Only when the tables have a primary key/foreign key relationship.

Show answer
Correct Option: C,E

AI Explanation

To answer this question, you need to understand the concept of joins in database queries.

An outer join is used to combine rows from two or more tables based on a related column, including unmatched rows. It includes rows from both tables, even if there is no match between the columns being joined. Outer joins are useful when you want to include all the rows from one table, regardless of whether there is a match in the other table.

Let's go through each option to understand why it is correct or incorrect:

Option A) The tables being joined have NOT NULL columns. - This option is incorrect because the presence of NOT NULL columns does not determine whether an outer join should be used.

Option B) The tables being joined have only matched data. - This option is incorrect because an outer join is used to include unmatched data as well.

Option C) The columns being joined have NULL values. - This option is correct because an outer join is typically used when the columns being joined have NULL values.

Option D) The tables being joined have only unmatched data. - This option is incorrect because an outer join is used to include both matched and unmatched data.

Option E) The tables being joined have both matched and unmatched data. - This option is correct because an outer join is typically used when there is both matched and unmatched data between the tables.

Option F) Only when the tables have a primary key/foreign key relationship. - This option is incorrect because an outer join can be used even when there is no primary key/foreign key relationship between the tables.

The correct answer is C,E. This option is correct because an outer join is commonly used when the columns being joined have NULL values and when there is both matched and unmatched data between the tables.

Which of the following is not a joke from Chet Haase's humor blog:

technology programming languages

  1. What do you call it when a chip manufacturer loses money? -- A cash miss.

  2. What do you call someone who has to use a dull web application? --Bored to tiers.

  3. What does a hungry vegetarian say? --"I´m so hungry, I could eat a tree."

  4. Always wear protective goggles when operating a weed-eater, working with a power tool, or teasing your wife.

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Correct Option: C