diff --git a/docs/en/12-taos-sql/01-data-type.md b/docs/en/12-taos-sql/01-data-type.md index a870d7b530b6c2dfc65f9cd4fe98907563fea208..70bea97dba24a7e3278afa2780a778630e375fb2 100644 --- a/docs/en/12-taos-sql/01-data-type.md +++ b/docs/en/12-taos-sql/01-data-type.md @@ -42,8 +42,6 @@ In TDengine, the data types below can be used when specifying a column or tag. | 14 | NCHAR | User Defined | Multi-byte string that can include multi byte characters like Chinese characters. Each character of NCHAR type consumes 4 bytes storage. The string value should be quoted with single quotes. Literal single quote inside the string must be preceded with backslash, like `\'`. The length must be specified when defining a column or tag of NCHAR type, for example nchar(10) means it can store at most 10 characters of nchar type and will consume fixed storage of 40 bytes. An error will be reported if the string value exceeds the length defined. | | 15 | JSON | | JSON type can only be used on tags. A tag of json type is excluded with any other tags of any other type. | | 16 | VARCHAR | User-defined | Alias of BINARY | -| 17 | GEOMETRY | User-defined | Geometry data type, like POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, GEOMETRYCOLLECTION. | - :::note - Only ASCII visible characters are suggested to be used in a column or tag of BINARY type. Multi-byte characters must be stored in NCHAR type. diff --git a/docs/en/12-taos-sql/11-geometry-function.md b/docs/en/12-taos-sql/11-geometry-function.md deleted file mode 100644 index 4f9f9ce56de45cc668b020a0625ff926a4685544..0000000000000000000000000000000000000000 --- a/docs/en/12-taos-sql/11-geometry-function.md +++ /dev/null @@ -1,160 +0,0 @@ ---- -sidebar_label: Geometry Functions -title: Geometry Functions -toc_max_heading_level: 4 ---- - -## Geometry Input Functions - -Geometry input functions create geometry data from WTK. - -### ST_GeomFromText - -```sql -ST_GeomFromText(VARCHAR WKT expr) -``` - -**Description**: Return a specified GEOMETRY value from Well-Known Text representation (WKT). - -**Return value type**: GEOMETRY - -**Applicable data types**: VARCHAR - -**Applicable table types**: standard tables and supertables - -**Explanations**： -- The input can be one of WTK string, like POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, GEOMETRYCOLLECTION. -- The output is a GEOMETRY data type, internal defined as binary string. - -## Geometry Output Functions - -Geometry output functions convert geometry data into WTK. - -### ST_AsText - -```sql -ST_AsText(GEOMETRY geom) -``` - -**Description**: Return a specified Well-Known Text representation (WKT) value from GEOMETRY data. - -**Return value type**: VARCHAR - -**Applicable data types**: GEOMETRY - -**Applicable table types**: standard tables and supertables - -**Explanations**： -- The output can be one of WTK string, like POINT, LINESTRING, POLYGON, MULTIPOINT, MULTILINESTRING, MULTIPOLYGON, GEOMETRYCOLLECTION. - -## Geometry Relationships Functions - -Geometry relationships functions determine spatial relationships between geometries. - -### ST_Intersects - -```sql -ST_Intersects(GEOMETRY geomA, GEOMETRY geomB) -``` - -**Description**: Compares two geometries and returns true if they intersect. - -**Return value type**: BOOL - -**Applicable data types**: GEOMETRY, GEOMETRY - -**Applicable table types**: standard tables and supertables - -**Explanations**： -- Geometries intersect if they have any point in common. - - -### ST_Equals - -```sql -ST_Equals(GEOMETRY geomA, GEOMETRY geomB) -``` - -**Description**: Returns TRUE if the given geometries are "spatially equal". - -**Return value type**: BOOL - -**Applicable data types**: GEOMETRY, GEOMETRY - -**Applicable table types**: standard tables and supertables - -**Explanations**： -- 'Spatially equal' means ST_Contains(A,B) = true and ST_Contains(B,A) = true, and the ordering of points can be different but represent the same geometry structure. - - -### ST_Touches - -```sql -ST_Touches(GEOMETRY geomA, GEOMETRY geomB) -``` - -**Description**: Returns TRUE if A and B intersect, but their interiors do not intersect. - -**Return value type**: BOOL - -**Applicable data types**: GEOMETRY, GEOMETRY - -**Applicable table types**: standard tables and supertables - -**Explanations**： -- A and B have at least one point in common, and the common points lie in at least one boundary. -- For Point/Point inputs the relationship is always FALSE, since points do not have a boundary. - - -### ST_Covers - -```sql -ST_Covers(GEOMETRY geomA, GEOMETRY geomB) -``` - -**Description**: Returns TRUE if every point in Geometry B lies inside (intersects the interior or boundary of) Geometry A. - -**Return value type**: BOOL - -**Applicable data types**: GEOMETRY, GEOMETRY - -**Applicable table types**: standard tables and supertables - -**Explanations**： -- A covers B means no point of B lies outside (in the exterior of) A. - - -### ST_Contains - -```sql -ST_Contains(GEOMETRY geomA, GEOMETRY geomB) -``` - -**Description**: Returns TRUE if geometry A contains geometry B. - -**Return value type**: BOOL - -**Applicable data types**: GEOMETRY, GEOMETRY - -**Applicable table types**: standard tables and supertables - -**Explanations**： -- A contains B if and only if all points of B lie inside (i.e. in the interior or boundary of) A (or equivalently, no points of B lie in the exterior of A), and the interiors of A and B have at least one point in common. - - -### ST_ContainsProperly - -```sql -ST_ContainsProperly(GEOMETRY geomA, GEOMETRY geomB) -``` - -**Description**: Returns TRUE if every point of B lies inside A. - -**Return value type**: BOOL - -**Applicable data types**: GEOMETRY, GEOMETRY - -**Applicable table types**: standard tables and supertables - -**Explanations**： -- There is no point of B lies in the the boundary or exterior of A.