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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.

1.

What is a view? Why should you use a view?

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2.

Which SQL statement is used to add, modify or drop columns in a database table?

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3.

What is the difference between VARCHAR2 AND CHAR datatypes?

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4.

What is the purpose of the MERGE statement in SQL?

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5.

Can you remove rows from a table based on values from another table? Explain.

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6.

What happens if you omit the WHERE clause in a delete statement?

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7.

Can you modify the rows in a table based on values from another table? Explain.

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8.

What happens if you omit the WHERE clause in the UPDATE statement?

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9.

How do you copy rows from one table to another?

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10.

How do you insert null values in a column while inserting data?

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11.

Which statement is used to add a new row in a database table?

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12.

What is the pupose of DML statements in SQL?

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13.

What are the various multiple row comparison operators in SQL?

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14.

What do you understand by a subquery? When is it used?

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15.

What’s wrong in the following query?

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16.

What is the purpose of the group functions in SQL? Give some examples of group functions.

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17.

What is the difference between cross joins and natural joins?

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18.

You want to display a result query from joining two tables with 20 and 10 rows respectively. Erroneously you forget to write the WHERE clause. What would be the result?

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19.

Which expressions or functions allow you to implement conditional processing in a SQL statement?

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20.

Discuss the syntax and use of the COALESCE function?

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21.

What is the use of the NULLIF function?

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22.

What is the difference between the NVL and the NVL2 functions?

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23.

What is the purpose of the NVL function?

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24.

Which function returns the remainder in a division operation?

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25.

What are the case manipulation functions of SQL?

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26.

What are the specific uses of SQL functions?

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27.

What is the default ordering of data using the ORDER BY clause? How could it be changed?

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28.

How do you search for a value in a database table when you don’t have the exact value to search for?

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29.

What is the purpose of the condition operators BETWEEN and IN?

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30.

If a table contains duplicate rows, does a query result display the duplicate values by default? How can you eliminate duplicate rows from a query result?

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31.

Say True or False. Give explanation if False.

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32.

Is a NULL value same as zero or a blank space? If not then what is the difference?

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33.

Can you sort a column using a column alias?

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34.

What are various DCL commands in SQL? Give brief description of their purposes.

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35.

What are various DML commands in SQL? Give brief description of their purposes.

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36.

What are various DDL commands in SQL? Give brief description of their purposes.

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37.

What is the difference between SQL and PL/SQL?

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38.

What is the difference between SQL and MySQL or SQL Server?

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