Exam 70-761 topic 1 question 20 discussion

Actual exam question from Microsoft's 70-761

Question #: 20
Topic #: 1

SIMULATION -
You work for an organization that monitors seismic activity around volcanos. You have a table named GroundSensors. The table stored data collected from seismic sensors. It includes the columns describes in the following table:

The database also contains a scalar value function named NearestMountain that returns the name of the mountain that is nearest to the sensor.
You need to create a query that shows the average of the normalized readings from the sensors for each mountain. The query must meet the following requirements:
✑ Include the average normalized readings and nearest mountain name.
✑ Exclude sensors for which no normalized reading exists.
✑ Exclude those sensors with value of zero for tremor.
Construct the query using the following guidelines:
✑ Use one part names to reference tables, columns and functions.
✑ Do not use parentheses unless required.
✑ Do not use aliases for column names and table names.
Do not surround object names with square brackets.

Part of the correct Transact-SQL has been provided in the answer area below. Enter the code in the answer area that resolves the problem and meets the stated goals or requirements. You can add code within the code that has been provided as well as below it.

Use the Check Syntax button to verify your work. Any syntax or spelling errors will be reported by line and character position.

Show Suggested Answer

Suggested Answer: Please see explanation
SELECT Average(NormalizedReading), NearestMountain(SensorID)

FROM GroundSensors -
WHERE TREMOR IS NOT 0 AND NormalizedReading IS NOT NULL
GROUP BY NearestMountain(SensorID)
GROUP BY is a SELECT statement clause that divides the query result into groups of rows, usually for the purpose of performing one or more aggregations on each group. The SELECT statement returns one row per group.
References:
https://msdn.microsoft.com/en-us/library/ms177673.aspx

by Dieter at Aug. 19, 2019, 11:27 a.m.

upvoted 4 times

Anette

5 years, 1 month ago

yes but it is calculated in NearestMountain Function through Sensor ID

upvoted 2 times

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prakash101179

5 years, 8 months ago

Answer should be - Select avg(normalizedreading), NearestMountain(SensorID) from groundsensor where normalizedreading is not null or tremor <> 0 group by NearestMountain(SensorID)

upvoted 6 times

Barbedx

5 years, 4 months ago

this should be AND statement

upvoted 5 times

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M4x

5 years, 9 months ago

SELECT Average(NormalizedReading), NearestMountain(SensorID) must be SELECT AVG(NormalizedReading), NearestMountain(SensorID)

upvoted 5 times

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