Functions that return coordinate and measure information
You can use certain functions to return information about the coordinates and measures within a geometry.
For example, ST_X can return the X coordinate within a specified point, ST_MaxX returns the highest X coordinate within a geometry, and ST_MinX returns the lowest X coordinate within a geometry.
Use the following functions to return coordinate and measure information:
- ST_Is3D
- Takes a geometry as an input parameter and returns 1 if the given geometry has Z coordinates. Otherwise, 0 (zero) is returned.
- ST_IsMeasured
- Takes a geometry as an input parameter and returns 1 if the given geometry has M coordinates (measures). Otherwise 0 (zero) is returned.
- ST_IsValid
- Takes a geometry as an input parameter and returns 1 if it is valid. Otherwise 0 (zero) is returned.
- ST_M
- If a measure is stored with a given point, takes the point as an input parameter and return the measure.
- ST_MaxM
- Takes a geometry as an input parameter and returns its maximum measure.
- ST_MaxX
- Takes a geometry as an input parameter and returns its maximum X coordinate.
- ST_MaxY
- Takes a geometry as an input parameter and returns its maximum Y coordinate.
- ST_MaxZ
- Takes a geometry as an input parameter and returns its maximum Z coordinate.
- ST_MinM
- Takes a geometry as an input parameter and returns its minimum measure.
- ST_MinX
- Takes a geometry as an input parameter and returns its minimum X coordinate.
- ST_MinY
- Takes a geometry as an input parameter and returns its minimum Y coordinate.
- ST_MinZ
- Takes a geometry as an input parameter and returns its minimum Z coordinate.
- ST_X
- Takes a point as an input parameter and return the point's X coordinate.
- ST_Y
- Takes a point as an input parameter and return the point's Y coordinate.
- ST_Z
- If a Z coordinate is stored with a given point, takes the point as an input parameter and return the Z coordinate.