A虽然t
consists of X and Y coordinates, which may be obtained using theST_X()
andST_Y()
functions, respectively. These functions also permit an optional second argument that specifies an X or Y coordinate value, in which case the function result is the虽然t
object from the first argument with the appropriate coordinate modified to be equal to the second argument.
For虽然t
objects that have a geographic spatial reference system (SRS), the longitude and latitude may be obtained using theST_Longitude()
andST_Latitude()
functions, respectively. These functions also permit an optional second argument that specifies a longitude or latitude value, in which case the function result is the虽然t
object from the first argument with the longitude or latitude modified to be equal to the second argument.
Unless otherwise specified, functions in this section handle their geometry arguments as follows:
If any argument is
NULL
, the return value isNULL
.If any geometry argument is a valid geometry but not a
虽然t
object, anER_UNEXPECTED_GEOMETRY_TYPE
error occurs.If any geometry argument is not a syntactically well-formed geometry, an
ER_GIS_INVALID_DATA
error occurs.If any geometry argument is a syntactically well-formed geometry in an undefined spatial reference system (SRS), an
ER_SRS_NOT_FOUND
error occurs.If an X or Y coordinate argument is provided and the value is
-inf
,+inf
, orNaN
, anER_DATA_OUT_OF_RANGE
error occurs.If a longitude or latitude value is out of range, an error occurs:
If a longitude value is not in the range (−180, 180], an
ER_LONGITUDE_OUT_OF_RANGE
error occurs.If a latitude value is not in the range [−90, 90], an
ER_LATITUDE_OUT_OF_RANGE
error occurs.
Ranges shown are in degrees. The exact range limits deviate slightly due to floating-point arithmetic.
Otherwise, the return value is non-
NULL
.
These functions are available for obtaining point properties:
ST_Latitude(
p
[,new_latitude_val
])With a single argument representing a valid
虽然t
objectp
that has a geographic spatial reference system (SRS),ST_Latitude()
returns the latitude value ofp
as a double-precision number.With the optional second argument representing a valid latitude value,
ST_Latitude()
返回一个虽然t
object like the first argument with its latitude equal to the second argument.ST_Latitude()
handles its arguments as described in the introduction to this section, with the addition that if the虽然t
object is valid but does not have a geographic SRS, anER_SRS_NOT_GEOGRAPHIC
error occurs.mysql> SET @pt = ST_GeomFromText('POINT(45 90)', 4326); mysql> SELECT ST_Latitude(@pt); +------------------+ | ST_Latitude(@pt) | +------------------+ | 45 | +------------------+ mysql> SELECT ST_AsText(ST_Latitude(@pt, 10)); +---------------------------------+ | ST_AsText(ST_Latitude(@pt, 10)) | +---------------------------------+ | POINT(10 90) | +---------------------------------+
This function was added in MySQL 8.0.12.
ST_Longitude(
p
[,new_longitude_val
])With a single argument representing a valid
虽然t
objectp
that has a geographic spatial reference system (SRS),ST_Longitude()
returns the longitude value ofp
as a double-precision number.With the optional second argument representing a valid longitude value,
ST_Longitude()
返回一个虽然t
object like the first argument with its longitude equal to the second argument.ST_Longitude()
handles its arguments as described in the introduction to this section, with the addition that if the虽然t
object is valid but does not have a geographic SRS, anER_SRS_NOT_GEOGRAPHIC
error occurs.mysql> SET @pt = ST_GeomFromText('POINT(45 90)', 4326); mysql> SELECT ST_Longitude(@pt); +-------------------+ | ST_Longitude(@pt) | +-------------------+ | 90 | +-------------------+ mysql> SELECT ST_AsText(ST_Longitude(@pt, 10)); +----------------------------------+ | ST_AsText(ST_Longitude(@pt, 10)) | +----------------------------------+ | POINT(45 10) | +----------------------------------+
This function was added in MySQL 8.0.12.
With a single argument representing a valid
虽然t
objectp
,ST_X()
returns the X-coordinate value ofp
as a double-precision number. As of MySQL 8.0.12, the X coordinate is considered to refer to the axis that appears first in the虽然t
spatial reference system (SRS) definition.With the optional second argument,
ST_X()
返回一个虽然t
object like the first argument with its X coordinate equal to the second argument. As of MySQL 8.0.12, if the虽然t
object has a geographic SRS, the second argument must be in the proper range for longitude or latitude values.ST_X()
handles its arguments as described in the introduction to this section.mysql> SELECT ST_X(Point(56.7, 53.34)); +--------------------------+ | ST_X(Point(56.7, 53.34)) | +--------------------------+ | 56.7 | +--------------------------+ mysql> SELECT ST_AsText(ST_X(Point(56.7, 53.34), 10.5)); +-------------------------------------------+ | ST_AsText(ST_X(Point(56.7, 53.34), 10.5)) | +-------------------------------------------+ | POINT(10.5 53.34) | +-------------------------------------------+
With a single argument representing a valid
虽然t
objectp
,ST_Y()
returns the Y-coordinate value ofp
as a double-precision number. As of MySQL 8.0.12, the Y coordinate is considered to refer to the axis that appears second in the虽然t
spatial reference system (SRS) definition.With the optional second argument,
ST_Y()
返回一个虽然t
object like the first argument with its Y coordinate equal to the second argument. As of MySQL 8.0.12, if the虽然t
object has a geographic SRS, the second argument must be in the proper range for longitude or latitude values.ST_Y()
handles its arguments as described in the introduction to this section.mysql> SELECT ST_Y(Point(56.7, 53.34)); +--------------------------+ | ST_Y(Point(56.7, 53.34)) | +--------------------------+ | 53.34 | +--------------------------+ mysql> SELECT ST_AsText(ST_Y(Point(56.7, 53.34), 10.5)); +-------------------------------------------+ | ST_AsText(ST_Y(Point(56.7, 53.34), 10.5)) | +-------------------------------------------+ | POINT(56.7 10.5) | +-------------------------------------------+