Defines column, column set, and index key structures.
The API has three key concepts: column, column set, and index key.
A table in a database is defined by a set of columns. Each column
has attributes such as a name, a type, and a maximum length (if text or
binary).
A column definition is encapsulated by
TDbCol
.
A set of columns that describe a table are encapsulated in
CDbColSet
. The set can be iterated over using
TDbColSetIter
.
An index key orders one or more table columns (keys). It has
attributes such as being unique or primary, a comparison specification for text
columns, and a list of columns which make up the key.
The index key is encapsulated in CDbKey
. A
column for the key is encapsulated in TDbKeyCol
.