SE 40470907, Sql Server

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CREATE TABLE Survey
    ([Hole] varchar(3), [Depth] int, [Az] int, [Dip] decimal(5,2))
;
    
INSERT INTO Survey
    ([Hole], [Depth], [Az], [Dip])
VALUES
    ('AB1', 0, 170, -77),
    ('AB1', 150, 166, -76.5),
    ('AB1', 200, 160, -75),
    ('AD1', 0, 350, -88),
    ('AD1', 65, 344, -87.6),
    ('AD1', 89, 340, -85.4),
    ('AB2', 0, 152, -66),
    ('AB2', 135, 150, -63.2)
;

select * from (
    
    --Get delta from 0 to 150 
SELECT s1.hole
	,s1.depth
	,s1.az
    ,s2.az as s2az
	,s1.dip
    ,s2.dip as s2dip
	,row_number() OVER (
		PARTITION BY s1.hole ORDER BY s1.depth 
		) AS rn
    
    ,s1.az-s2.az / (s1.depth - s2.depth) as DeltaAZ
    ,convert(decimal(5,2),s1.dip) - convert(decimal(5,2),s2.dip) / (s1.depth-s2.depth) as DeltaDip
      
FROM survey s1
inner JOIN (
	SELECT hole
		,depth
		,az
		,dip
		,row_number() OVER (
			PARTITION BY hole ORDER BY depth 
			) AS rn
	FROM survey
	) s2
	ON s1.hole = s2.hole
		AND s2.rn = 1 -- only return the second result
         
WHERE left(s1.hole, 3) = 'AB1'
)s1 where s1.rn = 2

union all 
    
       
    
    select * from (
SELECT s2.hole
	,s2.depth
	,s2.az
        ,s3.az as s2az
	,s2.dip
        ,s3.dip as s2dip
	,row_number() OVER (
		PARTITION BY s2.hole ORDER BY s2.depth 
		) AS rn
    
    ,s2.az-s3.az / (s2.depth - s3.depth) as DeltaAZ
    ,convert(decimal(5,2),s2.dip) - convert(decimal(5,2),s3.dip) / (s2.depth - s3.depth) as DeltaDip
    
FROM survey s2
    
    inner JOIN (
	SELECT hole
		,depth
		,az
		,dip
		,row_number() OVER (
			PARTITION BY hole ORDER BY depth 
			) AS rn
	FROM survey
	) s3
	ON s2.hole = s3.hole
		AND s3.rn = 2 -- only return the third result 
    )s2
    where s2.rn = 3
    and left(hole,2) = 'AB'
    
    
    
order by s1.hole,s1.depth

View schema
Execution time: 0,02 sec, rows selected: 2, rows affected: 8, absolute service time: 0,2 sec