Example: Differing Character Sets - Teradata Vantage

The server character set of the result of the following query is UNICODE because the CASE expression contains more than one nonliteral character expressions with differing character sets.

   SELECT i, CASE
               WHEN i=2 THEN column_u
               WHEN i=3 THEN column_j
               WHEN i=4 THEN column_g
               WHEN i=5 THEN column_k
               ELSE column_l
             END
   FROM table_1
   ORDER BY 1;

In the following query, the CASE expression returns a VARCHAR result because the THEN  and  ELSE clause contains FLOAT and VARCHAR values. The length of the result is 30 because the default format for FLOAT is a string less than 30 characters, and USER is defined as VARCHAR(30) CHARACTER SET UNICODE. The result is CHARACTER SET UNICODE because USER is UNICODE.

   SELECT a, CASE
                WHEN a=1 
                THEN TIME
                ELSE USER
               END
   FROM table_1
   ORDER BY 1;