• ST_X( p  [, new_x_val ]) 

With a single argument representing a valid Point  object p , ST_X()  returns the X-coordinate value of p  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 Point  spatial reference system (SRS) definition. 

With the optional second argument, ST_X()  returns a Point  object like the first argument with its X coordinate equal to the second argument. As of MySQL 8.0.12, if the Point  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) | +-------------------------------------------+ 

• ST_Y( p  [, new_y_val ]) 

With a single argument representing a valid Point  object p , ST_Y()  returns the Y-coordinate value of p  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 Point  spatial reference system (SRS) definition. 

With the optional second argument, ST_Y()  returns a Point  object like the first argument with its Y coordinate equal to the second argument. As of MySQL 8.0.12, if the Point  object has a geographic SRS, the second argument must be in the proper range for longitude or latitude values. 

## 12.17.7.3 LineString and MultiLineString Property Functions 

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) | +-------------------------------------------+ 

A LineString  consists of Point  values. You can extract particular points of a LineString , count the number of points that it contains, or obtain its length. 

Some functions in this section also work for MultiLineString  values. 

Unless otherwise specified, functions in this section handle their geometry arguments as follows: 

•If any argument is NULL  or any geometry argument is an empty geometry, the return value is NULL . 

