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Help in Understanding a SQL Query

Hi guys,

Can you please help me understand this query

SELECT  Point.STAsText() AS Wkt
	FROM AddressSearchString AS S
    WHERE NOT EXISTS (SELECT 42
					FROM [PhysicalSpace].[LocationShapes]
                    WHERE S.Point.STDistance(ShapeData) < 3.0 AND [IsPoint] = 1)
	GROUP BY Point.STAsText()

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What does Select 42 means?

regards

SOLUTION

Vitor Montalvão

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SOLUTION

Pawan Kumar

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Ali Shah

ASKER

Does this mean that there is no purpose of subquery here as it will always return null as 42 doesn't exist in the subquery table?

Pawan Kumar

No there is purpose , It is used in the where clause. In this case we need to take results where we should NOT have any rows from the Inner query.

Vitor Montalvão

To be honest all query seems very odd to me. You have 2 tables and there's no apparent connection between them.
Is the following query returning the same rows as the original one?

SELECT  Point.STAsText() AS Wkt
FROM AddressSearchString AS S
WHERE S.Point.STDistance(ShapeData) < 3.0 
GROUP BY Point.STAsText()

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ASKER CERTIFIED SOLUTION

Vitor Montalvão

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Ali Shah

ASKER

Thanks Vitor and Pawan. it explains it all. Learning very quickly with the help of you guys.

thanks again