SQL Practice Questions: Test Your Knowledge!

What is the purpose of the GROUP BY clause in SQL?

To join tables

To filter rows

To sort results

To group rows with similar values

Which SQL function is used to round a number to a specified number of decimal places?

CEIL()

FLOOR()

ROUND()

TRUNCATE()

What is the difference between DELETE and TRUNCATE in SQL?

DELETE removes specific rows, TRUNCATE removes all rows

DELETE is faster, TRUNCATE is slower

TRUNCATE can be rolled back, DELETE cannot

There is no difference

Which SQL function returns the number of rows affected by an INSERT, UPDATE, or DELETE statement?

ROW_COUNT()

AFFECTED_ROWS()

CHANGED_ROWS()

MODIFIED_ROWS()

Which SQL keyword is used to specify a common table expression (CTE)?

WITH

USING

FROM

Which SQL function returns the smallest value in a set of values?

MIN

SMALLEST

LEAST

MINIMUM

What is the purpose of the SQL WINDOW function?

To define a named window specification for reuse in multiple window functions

To filter rows based on a condition

To sort the result set in ascending or descending order

To join tables based on a common column

Which SQL keyword is used to filter rows based on a condition?

SELECT

WHERE

FILTER

Which SQL function is used to calculate the sample standard deviation of a numeric column?

STDEV

STDDEV_SAMP

VARIANCE

DEVIATION

Which SQL statement is used to create a new index on a table?

CREATE INDEX

ALTER INDEX

INSERT INDEX

UPDATE INDEX

What is the purpose of the SQL CONCAT function?

To concatenate two or more strings together

To check if an expression is NULL

To return the first non-null value in a list of expressions

To replace NULL values with a specified value

What is the purpose of data aggregation in the ETL process?

To combine data from multiple sources

To summarize data at a higher level

To filter data based on specific criteria

To sort data in a specific order

Which SQL function is used to extract a substring from a string?

EXTRACT()

CUT()

SUBSTRING()

SLICE()

Which SQL statement is used to create a trigger?

CREATE TRIGGER

MAKE TRIGGER

BUILD TRIGGER

NEW TRIGGER

What is the purpose of the SQL PERCENT_RANK function?

To calculate the cumulative distribution of a value within a partition

To calculate the percentile rank of a value within a partition

To calculate the rank of a value within a partition

To calculate the dense rank of a value within a partition

Which SQL statement is used to create a new user-defined function?

CREATE FUNCTION

ALTER FUNCTION

DROP FUNCTION

NEW FUNCTION

What is the purpose of the SQL REGR_AVGY() function?

To calculate the average of the dependent variable in the linear regression between two numeric columns

To calculate the average of the independent variable in the linear regression between two numeric columns

To calculate the sum of squares of the independent variable in the linear regression between two numeric columns

To calculate the sum of squares of the dependent variable in the linear regression between two numeric columns

Which SQL function is used to perform window function calculations?

OVER

PARTITION BY

WINDOW

ANALYTICS

Which SQL function is used to calculate the variance of a set of values?

VAR

VARIANCE

VAR_POP

VAR_SAMP

Which SQL statement is used to insert new data into a database?

UPDATE

DELETE

SELECT

INSERT

Score: 0/20