ST_IsSimple(g)

Returns 1 if the geometry value g is simple according to the ISO SQL/MM
Part 3: Spatial standard. ST_IsSimple() returns 0 if the argument is
not simple.

The descriptions of the instantiable geometric classes given under
https://dev.mysql.com/doc/refman/8.0/en/opengis-geometry-model.html
include the specific conditions that cause class instances to be
classified as not simple.

ST_IsSimple() handles its arguments as described in the introduction to
this section, with this exception:

o If the geometry has a geographic SRS with a longitude or latitude
  that is out of range, an error occurs:

  o If a longitude value is not in the range (−180, 180], an
    ER_GEOMETRY_PARAM_LONGITUDE_OUT_OF_RANGE
    (https://dev.mysql.com/doc/mysql-errors/8.0/en/server-error-referen
    ce.html#error_er_geometry_param_longitude_out_of_range) error
    occurs (ER_LONGITUDE_OUT_OF_RANGE
    (https://dev.mysql.com/doc/mysql-errors/8.0/en/server-error-referen
    ce.html#error_er_longitude_out_of_range) prior to MySQL 8.0.12).

  o If a latitude value is not in the range [−90, 90], an
    ER_GEOMETRY_PARAM_LATITUDE_OUT_OF_RANGE
    (https://dev.mysql.com/doc/mysql-errors/8.0/en/server-error-referen
    ce.html#error_er_geometry_param_latitude_out_of_range) error occurs
    (ER_LATITUDE_OUT_OF_RANGE
    (https://dev.mysql.com/doc/mysql-errors/8.0/en/server-error-referen
    ce.html#error_er_latitude_out_of_range) prior to MySQL 8.0.12).

  Ranges shown are in degrees. The exact range limits deviate slightly
  due to floating-point arithmetic.

URL: https://dev.mysql.com/doc/refman/8.0/en/gis-general-property-functions.html

