Teradata Database performs implicit UDT-to-TIME conversions for the following operations:
- UPDATE
- INSERT
- Passing arguments to stored procedures, external stored procedures, UDFs, and UDMs
- Specific system operators and functions identified in other sections of this document, unless the DisableUDTImplCastForSysFuncOp field of the DBS Control Record is set to TRUE
Performing an implicit data type conversion requires that an appropriate cast definition (see Usage Notes) exists that specifies the AS ASSIGNMENT clause.
If no UDT-to-TIME implicit cast definition exists, Teradata Database looks for a UDT-to-CHAR or UDT-to-VARCHAR cast definition that can substitute for the UDT-to-TIME implicit cast definition. Substitutions are valid because Teradata Database can use the implicit cast definition to cast the UDT to a character data type, and then implicitly cast the character data type to a DATE type. If multiple UDT-to-character implicit cast definitions exist, then Teradata Database returns an SQL error.