STPolyFromText (geography Data Type)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Returns a geography instance from an Open Geospatial Consortium (OGC) Well-Known Text (WKT) representation augmented with any Z (elevation) and M (measure) values carried by the instance.
Syntax
STPolyFromText ( 'polygon_tagged_text' , SRID )
Arguments
polygon_tagged_text
Is the WKT representation of the geographyPolygon instance you wish to return. polygon_tagged_text is an nvarchar(max) expression.
SRID
Is an int expression representing the spatial reference ID (SRID) of the geographyPolygon instance you wish to return.
Return Types
SQL Server return type: geography
CLR return type: SqlGeography
OGC type: Polygon
Remarks
This method throws a FormatException if the input is not well-formatted.
Note
The order in which the points are listed matters for geography polygons. It determines if the polygon area is to the inside or outside of the given ring. See Polygon for more information.
Examples
The following example uses STPolyFromText() to create a geography instance.
DECLARE @g geography;
SET @g = geography::STPolyFromText('POLYGON((-122.358 47.653, -122.348 47.649, -122.348 47.658, -122.358 47.658, -122.358 47.653))', 4326);
SELECT @g.ToString();