B.4.1 Obtaining Result from Arguments with Different Data Types

Oracle database

SELECT NVL( col1,
            col2)
  FROM t1;

* col1 is assumed to be VARCHAR(100) type, and col2 is assumed to be CHAR(100) type

Symfoware Server

SELECT NVL( col1,
            CAST(col2 AS VARCHAR(100)))
  FROM t1;

* col1 is assumed to be VARCHAR(100) type, and col2 is assumed to be CHAR(100) type

Feature differences

Oracle database: Value expressions with different data types can be specified. If the first argument is a string value, then VARCHAR2 is returned, and if it is a numeric, then a numeric type with greater range is returned.

Symfoware Server: Value expressions with different data types cannot be specified.

Conversion procedure

Since the data types that can be specified for expressions 1 and 2 are unknown, use the following steps to convert:

Check the data types specified for the expressions 1 and 2.
Using the data type that is to be received as a result, explicitly convert the other argument with CAST.