16.20 - Implicit Type Conversion - Teradata Vantage NewSQL Engine

Teradata Vantageā„¢ Data Types and Literals

prodname
Teradata Database
Teradata Vantage NewSQL Engine
vrm_release
16.20
category
Programming Reference
featnum
B035-1143-162K

Performing an implicit data type conversion requires that an appropriate cast definition exists that specifies the AS ASSIGNMENT clause.

Teradata Database performs implicit UDT-to-DATE 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

If no UDT-to-DATE implicit cast definition exists, Teradata Database looks for other cast definitions that can substitute for the UDT-to-DATE implicit cast definition:

Combination of Implicit Cast Definitions Description
UDT-to-Numeric UDT-to-Character

(non-CLOB)

 
X   Teradata Database uses the UDT-to-numeric implicit cast definition.

If multiple UDT-to-numeric implicit cast definitions exist, then Teradata Database returns an SQL error.

  X Teradata Database uses the UDT-to-character implicit cast definition.

If multiple UDT-to-character implicit cast definitions exist, then Teradata Database returns an SQL error.

X X Teradata Database reports an error.

Substitutions are valid because Teradata Database can use the implicit cast definition to cast the UDT to the substitute data type, and then implicitly cast the substitute data type to a DATE type.