Teradata Database implements cast functionality that allows data type conversions between the following types:
- ST_Geometry and VARCHAR(64000)
- ST_Geometry and CLOB
To cast a VARCHAR or CLOB to an ST_Geometry type, the VARCHAR or CLOB data must use the WKT format of any of the ST_Geometry subtypes. For example:
INSERT INTO sample_shapes VALUES (1001, CAST('LINESTRING(1 1, 2 2, 3 3)' AS ST_Geometry));
For more information on the WKT format of the ST_Geometry type, see Well-Known Text Format.