Numeric type promotion in expressions

In expressions that use only integer types, Derby promotes the type of the result to at least INTEGER. In expressions that mix integer with non-integer types, Derby promotes the result of the expression to the highest type in the expression.

The following table shows the promotion of data types in expressions.

Table 1. Type promotion in expressions
Largest Type That Appears in Expression	Resulting Type of Expression
DOUBLE PRECISION	DOUBLE PRECISION
REAL	DOUBLE PRECISION
DECIMAL	DECIMAL
BIGINT	BIGINT
INTEGER	INTEGER
SMALLINT	INTEGER

For example:

-- returns a double precision
VALUES 1 + 1.0e0
-- returns a decimal
VALUES 1 + 1.0
-- returns an integer
VALUES CAST (1 AS INT) + CAST (1 AS INT)