Teradata Database performs implicit TIME-to-UDT 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 TIME-to-UDT implicit cast definition exists, Teradata Database looks for a CHAR-to-UDT or VARCHAR-to-UDT implicit cast definition that can substitute for the TIME-to-UDT implicit cast definition. Substitutions are valid because Teradata Database can implicitly cast a TIME type to the character data type, and then use the implicit cast definition to cast from the character data type to the UDT. If multiple character-to-UDT implicit cast definitions exist, then Teradata Database returns an SQL error.