构造点，线，多边形

用 ST_Point(6, 10) 函数构造点, 用 ST_LineFromText('linestring (10 10 , 20 20 )') 函数构造线, 用 ST_Polygon('polygon ((10 10, 10 20, 20 20, 20 15, 10 10))') 函数构造多边形， 用表格展示

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SELECT
  ST_Point(6, 10) as "点",
  ST_LineFromText('linestring (10 10 , 20 20 )') as "线",
  ST_Polygon('polygon ((10 10, 10 20, 20 20, 20 15, 10 10))') as "多边形"

SQL查询结果样例：