17.10 - Implicit Type Conversion - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - Data Types and Literals

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1143-171K
Language
English (United States)

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

SQL Engine 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, Vantage 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   Vantage uses the UDT-to-numeric implicit cast definition.

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

  X Vantage uses the UDT-to-character implicit cast definition.

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

X X SQL Engine reports an error.

Substitutions are valid because SQL Engine 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.