The following restrictions apply to CLOB, BLOB, and UDT types in a CASE expression:
|BLOB||A BLOB can only appear in value_expression_1, value_expression_n, scalar_expression_m, or scalar_expression_n when it is cast to BYTE or VARBYTE.|
|CLOB||A CLOB can only appear in value_expression_1, value_expression_n, scalar_expression_m, or scalar_expression_n when it is cast to CHAR or VARCHAR.|
|UDT||Multiple UDTs can appear in a CASE expression, with the following restrictions:
Teradata Database does not perform implicit type conversion on UDTs in CASE expressions. A workaround for this restriction is to use CREATE CAST to define casts that cast between the UDTs, and then explicitly invoke the CAST function in the CASE expression. For more information on CREATE CAST, see Teradata Vantage™ - SQL Data Definition Language Syntax and Examples, B035-1144.