i have give three different type of approach tak which one you want

DECLARE @GEOLINE TABLE

(

GEOLINE_ID INT IDENTITY(1,1) NOT NULL

,GEOLINE_LINE GEOMETRY NOT NULL

);

INSERT INTO @GEOLINE (GEOLINE_LINE)

VALUES

(geometry::STGeomFromText('LINESTRING(0 1, 6 0)', 0))

,(geometry::STGeomFromText('LINESTRING(0 2, 5 0)', 0))

,(geometry::STGeomFromText('LINESTRING(0 3, 4 0)', 0))

,(geometry::STGeomFromText('LINESTRING(0 4, 3 0)', 0))

,(geometry::STGeomFromText('LINESTRING(0 5, 2 0)', 0))

,(geometry::STGeomFromText('LINESTRING(0 6, 1 0)', 0))

,(geometry::STGeomFromText('LINESTRING(4 4, 3 6)', 0));

/*******************************************

* for just select the interSEcted lines

*******************************************/

SELECT g.GEOLINE_LINE FROM @GEOLINE g

WHERE EXISTS

(SELECT 1 FROM @GEOLINE g1 WHERE g.GEOLINE_LINE.STIntersects(g1.GEOLINE_LINE)=1)

/*******************************************

* for just select the aLL lines

*******************************************/

SELECT g.GEOLINE_LINE ,g.GEOLINE_LINE.STIntersection(g1.GEOLINE_LINE).STBuffer(0.05) AS Intersctions FROM @GEOLINE g

INNER JOIN @GEOLINE g1 ON g.GEOLINE_LINE.STIntersects(g1.GEOLINE_LINE)=1 AND g.GEOLINE_LINE.ToString()<>g1.GEOLINE_LINE.ToString()

/*******************************************

* Overlayer

*******************************************/

SELECT x.allgeo FROM @GEOLINE g

LEFT JOIN @GEOLINE g1 ON g.GEOLINE_LINE.STIntersects(g1.GEOLINE_LINE)=1 AND g.GEOLINE_LINE.ToString()<>g1.GEOLINE_LINE.ToString()

CROSS APPLY

(

VALUES

(g.GEOLINE_LINE) ,(g.GEOLINE_LINE.STIntersection(g1.GEOLINE_LINE).STBuffer(0.2))

)AS x (AllGeo)

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