It can be used to answer questions such as which Point  lies halfway along the road described by the geometry argument. 

The function is implemented for LineString  geometries in all spatial reference systems, both Cartesian and geographic. 

If the fractional_distance  argument is 1.0, the result may not be exactly the last point of the LineString  argument but a point close to it due to numerical inaccuracies in approximate-value computations. 

A related function, ST_LineInterpolatePoints() , takes similar arguments but returns a MultiPoint  consisting of Point  values along the LineString  at each fraction of the distance from its start point to its endpoint. For examples of both functions, see the ST_LineInterpolatePoints() description. 

ST_LineInterpolatePoint()  handles its arguments as described in the introduction to this section, with these exceptions: 

•If the geometry argument is not a LineString , an ER_UNEXPECTED_GEOMETRY_TYPE  error occurs. 

•If the fractional distance argument is outside the range [0.0, 1.0], an ER_DATA_OUT_OF_RANGE  error occurs. 

ST_LineInterpolatePoint()  is a MySQL extension to OpenGIS. This function was added in MySQL 8.0.24. 

• ST_LineInterpolatePoints( ls , fractional_distance ) 

This function takes a LineString  geometry and a fractional distance in the range (0.0, 1.0] and returns the MultiPoint  consisting of the LineString  start point, plus Point  values along the LineString at each fraction of the distance from its start point to its endpoint. It can be used to answer questions such as which Point  values lie every 10% of the way along the road described by the geometry argument. 

The function is implemented for LineString  geometries in all spatial reference systems, both Cartesian and geographic. 

If the fractional_distance  argument divides 1.0 with zero remainder the result may not contain the last point of the LineString  argument but a point close to it due to numerical inaccuracies in approximate-value computations. 

A related function, ST_LineInterpolatePoint() , takes similar arguments but returns the Point along the LineString  at the given fraction of the distance from its start point to its endpoint. 

ST_LineInterpolatePoints()  handles its arguments as described in the introduction to this section, with these exceptions: 

•If the geometry argument is not a LineString , an ER_UNEXPECTED_GEOMETRY_TYPE  error occurs. 

•If the fractional distance argument is outside the range [0.0, 1.0], an ER_DATA_OUT_OF_RANGE  error occurs. 

mysql> SET @ls1 = ST_GeomFromText(’LINESTRING(0 0,0 5,5 5)’); mysql> SELECT ST_AsText(ST_LineInterpolatePoint(@ls1, .5)); +----------------------------------------------+ | ST_AsText(ST_LineInterpolatePoint(@ls1, .5)) | +----------------------------------------------+ | POINT(0 5) | 

