For geometry values, MySQL distinguishes between the concepts of syntactically well-formed and geometrically valid.对于几何值，MySQL区分语法良好和几何有效的概念。
A geometry is syntactically well-formed if it satisfies conditions such as those in this (nonexhaustive) list:如果一个几何满足以下（非穷尽）列表中的条件，则它在语法上是良好的：
Linestrings have at least two points字符串至少有两点
Polygons have at least one ring多边形至少有一个环
Polygon rings are closed (first and last points the same)多边形环是闭合的（第一个点和最后一个点相同）
Polygon rings have at least 4 points (minimum polygon is a triangle with first and last points the same)多边形环至少有4个点（最小多边形是第一个点和最后一个点相同的三角形）
Collections are not empty (except 集合不为空（GeometryCollection)GeometryCollection除外）
A geometry is geometrically valid if it is syntactically well-formed and satisfies conditions such as those in this (nonexhaustive) list:如果一个几何结构在语法上是良好的，并且满足以下（非穷尽）列表中的条件，那么它在几何上是有效的：
Polygons are not self-intersecting多边形不自相交
Polygon interior rings are inside the exterior ring多边形内环位于外环内部
Multipolygons do not have overlapping polygons多边形没有重叠的多边形
Spatial functions fail if a geometry is not syntactically well-formed. Spatial import functions that parse WKT or WKB values raise an error for attempts to create a geometry that is not syntactically well-formed. 如果一个几何体的语法结构不好，空间函数就会失效。解析WKT或WKB值的空间导入函数会导致尝试创建语法不正确的几何图形时出错。Syntactic well-formedness is also checked for attempts to store geometries into tables.还检查语法的良好形式，以尝试将几何图形存储到表中。
It is permitted to insert, select, and update geometrically invalid geometries, but they must be syntactically well-formed. Due to the computational expense, MySQL does not check explicitly for geometric validity. 允许插入、选择和更新几何上无效的几何图形，但它们必须具有良好的语法形式。由于计算开销，MySQL不会显式检查几何有效性。Spatial computations may detect some cases of invalid geometries and raise an error, but they may also return an undefined result without detecting the invalidity. 空间计算可能会检测到一些无效几何形状的情况并引发错误，但它们也可能在没有检测到无效的情况下返回未定义的结果。Applications that require geometically valid geometries should check them using the 需要几何有效几何图形的应用程序应使用ST_IsValid() function.ST_IsValidat()函数进行检查。