Q 61. A subquery in an SQL SELECT statement is enclosed in:
A. brackets — […].
B. parenthesis — (…).
C. CAPITAL LETTERS.
D. braces — {…}.
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Answer:-B. parenthesis — (…).Explanation
In SQL, a subquery is enclosed in parentheses, as shown in Option A. Subqueries are used to retrieve data from one table and use that data as a condition for another query. The syntax for subqueries requires using parentheses to enclose the subquery within the main query. Options B, C, and D do not represent the correct way to enclose subqueries in SQL.Q 62. The result of a SQL SELECT statement is a ________ .
A. table
B. report
C. file
D. form
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Answer:-A. tableExplanation
The result of a SQL SELECT statement is a table. When you execute a SELECT statement in SQL, it retrieves data from one or more tables and presents it as a result set, which is essentially a table of data. This result set can be used for various purposes, such as reporting, analysis, or further processing in your database. Options A, B, and D do not accurately represent the typical result of a SELECT statement in SQL.Q 63. In an SQL SELECT statement querying a single table, according to the SQL-92 standard the asterisk (*) means that:
A. all records with even partial criteria met are to be returned.
B. all records meeting the full criteria are to be returned.
C. all columns of the table are to be returned.
D. None of the above is correct.
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Answer:-C. all columns of the table are to be returned.Explanation
In SQL, when you use an asterisk (*) in a SELECT statement while querying a single table, it means that you want to retrieve all columns of the table. It’s a shorthand way to select all available columns without listing them explicitly. Options B and C do not accurately represent the usage of the asterisk in this context.Q 64. The HAVING clause does which of the following?
A. Acts EXACTLY like a WHERE clause.
B. Acts like a WHERE clause but is used for columns rather than groups.
C. Acts like a WHERE clause but is used for groups rather than rows.
D. Acts like a WHERE clause but is used for rows rather than columns.
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Answer:-C. Acts like a WHERE clause but is used for groups rather than rows.Explanation
The HAVING clause in SQL is used to filter the results of a GROUP BY query based on a specified condition. It is similar to the WHERE clause, but it operates on grouped rows rather than individual rows. It allows you to filter groups that meet certain criteria, and it is typically used in combination with aggregate functions such as SUM, COUNT, AVG, etc., to filter grouped results. So, Option C accurately describes the purpose and functionality of the HAVING clause.Q 65. Which of the following do you need to consider when you make a table in SQL?
A. Data types
B. Primary keys
C. Default values
D. All of the above.
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Answer:-D. All of the above.Explanation
When creating a table in SQL, it’s essential to consider various aspects to define the table’s structure effectively. Data types: You need to specify the data types for each column to ensure that the data stored in the table is of the correct format. Data types include INTEGER, VARCHAR, DATE, etc., and they define what kind of data can be stored in each column. Primary keys: Primary keys uniquely identify each row in the table. They ensure that each record has a unique identifier, which is essential for maintaining data integrity. Default values: Default values can be set for columns. If no value is provided when inserting a new row, the default value is used. This is useful for columns where a value is likely to be consistent in most cases. So, all of these options (A, B, C) are important considerations when creating a table in SQL to define the table’s structure and behavior effectively.Q 66. When three or more AND and OR conditions are combined, it is easier to use the SQL keyword(s):
A. NOT IN only.
B. LIKE only.
C. IN only.
D. Both IN and NOT IN.
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Answer:-D. Both IN and NOT IN.Explanation
Combining three or more AND and OR conditions in SQL queries can make the syntax complex and hard to read. However, using the IN and NOT IN keywords can simplify the query structure. These keywords allow for more concise and readable code when dealing with multiple conditions. For example, instead of writing multiple nested conditions, you can use IN or NOT IN to check if a value is within a specified set of values, which can significantly improve code readability and maintainability.Q 67. SQL can be used to:
A. create database structures only.
B. query database data only.
C. modify database data only.
D. All of the above can be done by SQL.
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Answer:-D. All of the above can be done by SQL.Explanation
SQL (Structured Query Language) is a versatile language that can be used for various purposes in database management. It can be used to perform all the actions mentioned in the options: Creating database structures: SQL allows you to create and define the structure of a database, including tables, relationships, constraints, and more. Querying database data: SQL is primarily known for its ability to retrieve, filter, and manipulate data from a database using SELECT statements. This is a fundamental feature of SQL. Modifying database data: SQL provides commands like INSERT, UPDATE, and DELETE to add, modify, or remove data from a database. Therefore, SQL is a comprehensive language that can be used for all of the above purposes in database management.Q 68. The SQL keyword BETWEEN is used:
A. to limit the columns displayed.
B. for ranges.
C. as a wildcard.
D. None of these is correct.
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Answer:-B. for ranges.Explanation
The SQL keyword “BETWEEN” is used to define a range in SQL. It is typically used in the WHERE clause of a SELECT statement to filter rows based on a specified range of values. The “BETWEEN” keyword is followed by two values, typically a lower and an upper bound, separated by the “AND” keyword. For example, you might use it to filter rows with values within a specific range, such as dates, numerical values, or text values. When “BETWEEN” is used in a query, it helps limit the results to only those rows that fall within the specified range, making it a useful tool for filtering and retrieving data. Therefore, the correct option is “Option B: for ranges,” as the primary purpose of the “BETWEEN” keyword in SQL is to specify a range of values for filtering and querying data.Q 69. Which of the following query is correct for using comparison operators in SQL?
A. SELECT name, course_name FROM student WHERE age>50 and
B. SELECT name, course_name FROM student WHERE age>50 and age
C. SELECT name, course_name FROM student WHERE age>50 and WHERE age
D. None of these
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Answer:-B. SELECT name, course_name FROM student WHERE age>50 and ageExplanation
In SQL, comparison operators are used to compare values in the WHERE clause to filter rows based on specified conditions. The correct usage of these operators is as follows: Greater than (>): Compares if a value is greater than another. Less than ( Compares if a value is less than another. The correct SQL syntax for using comparison operators to filter rows where the “age” column is greater than 50 and less than 80 is as shown in “Option B.” Let’s break down the correct query: SELECT name, course_name: This part of the query specifies the columns to be retrieved in the result. FROM student: It specifies the table from which the data is retrieved. WHERE age > 50 and age This part specifies the conditions for filtering the rows. It correctly uses the “>” and ” The correct option, therefore, is “Option B.”Q 70. How to select all data from student table starting the name from letter ‘r’?
A. SELECT * FROM student WHERE name LIKE ‘_r%’;
B. SELECT * FROM student WHERE name LIKE ‘%r%’;
C. SELECT * FROM student WHERE name LIKE ‘%r’;
D. SELECT * FROM student WHERE name LIKE ‘r%’;
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Answer:-D. SELECT * FROM student WHERE name LIKE ‘r%’;Explanation
To select all data from the “student” table where the names start with the letter ‘r,’ you can use the LIKE operator in SQL. Here’s an explanation of each option: Option A: SELECT * FROM student WHERE name LIKE ‘r%’; This option selects all rows where the “name” column starts with ‘r’.Q 71. Which of the following SQL query is correct for selecting the name of staffs from ‘staffinfo’ table where salary is 10,000 or 25,000?
A. SELECT name FROM staffinfo WHERE salary BETWEEN 10000 AND 25000;
B. SELECT name FROM staffinfo WHERE salary IN (10000, 25000);
C. Both A and B
D. None of the above
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Answer:-B. SELECT name FROM staffinfo WHERE salary IN (10000, 25000);Explanation
SELECT name FROM staffinfo WHERE salary IN (10000, 25000); This query correctly selects the names of staff members whose salary is either 10,000 or 25,000. The correct answer is Option B because it selects the names of staffs with salaries of 10,000 or 25,000, as required by the question.Q 72. Select the right statement to insert values to the student table.
A. INSERT student VALUES (
B. INSERT VALUES (
C. INSERT INTO student VALUES (
D. INSERT VALUES INTO student (
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Answer:-B. INSERT VALUES (Explanation
as it follows the proper syntax for inserting values into the “student” table in SQL.Q 73. …………. joins two or more tables based on a specified column value not equaling a specified column value in another table.
A. EQUIJOIN
B. NON-EQUIJOIN
C. OUTER JOIN
D. NATURAL JOIN
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Answer:-B. NON-EQUIJOINExplanation
NON-EQUIJOIN, as it accurately describes a join based on non-equality of column values in different tables.Q 74. In SQL, which command is used to change a table’s storage characteristics?
A. ALTER TABLE
B. MODIFY TABLE
C. CHANGE TABLE
D. None of these
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Answer:-A. ALTER TABLEExplanation
ALTER TABLE.Q 75. In SQL, which of the following is not a data definition language commands?
A. REVOKE
B. RENAME
C. UPDATE
D. GRANT
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Answer:-C. UPDATEExplanation
The other options, REVOKE, RENAME, and GRANT, are DDL commands used for managing user privileges, renaming database objects, and controlling access, respectively.Q 76. ‘AS’ clause is used in SQL for
A. Selection operation.
B. Rename operation.
C. Join operation.
D. Projection operation.
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Answer:-B. Rename operation.Explanation
In SQL, the ‘AS’ clause is used for renaming columns or tables. It is primarily used for the rename operation. When you use the ‘AS’ clause, you can give an alias or alternate name to a column or a table, making it more readable or meaningful in the query’s result.Q 77. Count function in SQL returns the number of
A. values.
B. distinct values.
C. groups.
D. columns.
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Answer:-A. values.Explanation
The COUNT function in SQL is used to return the number of values within a specified column. It counts the total number of rows in a result-set or the number of non-NULL values in a specific column. Here’s an explanation of each option: Option A: values. This is the correct answer. The COUNT function counts the total number of values (or rows) in a result-set or a specific column.Q 78. Which of the following is a valid SQL type?
A. CHARACTER
B. NUMERIC
C. FLOAT
D. All of the above
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Answer:-D. All of the aboveExplanation
All of the options provided (CHARACTER, NUMERIC, and FLOAT) are valid SQL data types: CHARACTER represents character strings or text. NUMERIC represents numeric values like integers and decimals. FLOAT represents floating-point numbers.Q 79. NULL is
A. the same as 0 for integer
B. the same as blank for character
C. the same as 0 for integer and blank for character
D. not a value
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