The inner call, to ST_Point(), creates a point geometry with latitude-longitude coordinates (SRID = 1).
内部调用（对 ST_Point()）创建一个具有纬度-经度坐标（SRID = 1）的点几何值。
Bad coordinates are reflected in the absence of associated point geometry values, and the trigger procedures fail silently.
错误的坐标表现为缺少相关联的点几何值，触发器过程会悄悄地终止。
When either of the coordinate columns in the source table is updated, a new point geometry must be constructed. The update trigger looks like this
当更新源表中的坐标列时，必须构造一个新的点几何值。
Then a new method is proposed to measure indirectly cutting angles of drills with arbitrary point geometry by measuring the curve of the main edge projected.
以此为基础，提出一种通过测量主刃投影曲线间接测量主刃各点切削角度的新方法，较好地解决了任意刃形钻头切削角度的测量问题。
The spatial table has a simple structure: a unique, integer column (objectid), one or more columns making up the primary key (copied from the source table), plus a single point-geometry column.
空间表的结构很简单：一个惟一的整数列(objectid)，组成主键的一个或多个列(从源表复制的)，以及一个点几何列。
The spatial table has a simple structure: a unique, integer column (objectid), one or more columns making up the primary key (copied from the source table), plus a single point-geometry column.
空间表的结构很简单：一个惟一的整数列(objectid)，组成主键的一个或多个列(从源表复制的)，以及一个点几何列。
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