Column

All values in a column of a database table have the same data type. A value in a row of a column is the smallest data unit that can be selected from a table, to which functions can be applied and that can be modified. Each column in a base table has a name that is unique within the table.

Column Types
Column Type	Description
Alphanumeric	Character string column All character strings in an alphanumeric column have the same length
Numeric	Floating or fixed point column All numbers in a floating point column have the same mantissa length All numbers in a fixed point column have the same format, that is, the same number of pre- and post-point decimal places

Columns
Property	Description (Links to SQL Reference Manual)
Name	Column Name (column_name)
Data Type	Data Type (data_type)
Dim	Dimension Maximum number of characters
Code Attribute	Code attribute
Key	If you select this option, you add this column to the primary key. Key Definition (key_definition) All columns in the primary key must be `NOT NULL` columns. You cannot use any columns of the `LOB` data type in the primary key. The database ensures that no `NULL` value exists in the key column and that no two data records in the table have the same values in all key columns.
Not Null	If you select this option, the value for this column cannot be a `NULL` value. Column Attributes (column_attributes)

More Information

SQL Reference Manual

Database Studio,