Qualified data type

A qualified data type is a built-in data type with additional specifications that provide information about the storage size, range of values, or precision of the data type.

For example, CHAR is a built-in data type, but CHAR(16) is a qualified data type because you are fixing its length. You must add a qualified data type to a BladeSmith project before you can use it as a component of an extended data type.

When you create a qualified data type in a BladeSmith project, BladeSmith adds to the list of data types from which you choose when creating extended data types. Qualified data types do not need SQL or source code.

For example, to create a collection data type that stores sets of 16-byte character strings, you must first create a CHAR(16) qualified data type. Then create the collection data type, choosing CHAR(16) as the base data type and SET as the constructor function. The new data type has the following SQL definition:

SET(CHAR(16) not null)

The following table lists the data types that take qualifications.

Table 1. Data types that take qualifications
Data type	Qualification
CHARACTER, CHAR	(size)
CHARACTER VARYING	(size, minimum)
DATETIME	largest_qualifier TO smallest_qualifier
DECIMAL, DEC	(precision, scale)
INTERVAL	largest_qualifier(n) TO smallest_qualifier(n)
MONEY	(precision, scale)
NCHAR	(size)
NVARCHAR	(size, minimum)
SERIAL, SERIAL8, BIGSERIAL	(start value)
VARCHAR	(size, minimum)

BladeSmith restricts your input for qualification values to valid choices.

See HCL OneDB™ Guide to SQL: Reference for more information about qualified data types.