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6.3.3 Column


   A column in a result set, a view, a table, or an SQLStructuredType.

   Superclasses

   Attribute

   Attributes

   characterSetName

The name of the character set used for the values in the column. This field applies only to columns whose datatype is a character string.

type:

multiplicity:

String
exactly one

   collationName

The name of the collation sequence used to sort the data values in the column. This applies only to columns whose datatype is a form of character string.

type:

multiplicity:

String
exactly one

   isNullable

Indicates if null values are valid in this column.

type:

multiplicity:

NullableType ( columnNoNulls | columnNullable | columnNullableUnknown )
exactly one

   length

The length of fixed length character or byte strings. Maximum length if length is variable.

type:

multiplicity:

Integer
zero or one

   precision

The total number of digits in the field.

type:

multiplicity:

constraints:

Integer
zero or one
Scale must be specified when precision is specified

   scale

The number of digits on the right of the decimal separator.

type:

multiplicity:

Integer
zero or one

   References

   referencedTableType

The column, used in an SQLStructuredType is a REF to a type. This references the REF’ed SQLStructuredType.

class:

defined by:

multiplicity:

inverse:

SQLStructuredType
ColumnRefStructuredType::referencedTableType
zero or one
SQLStructuredType::referencingColumn

   optionScopeColumnSet

Reference to the NamedColumnSet (Table or View) indicated in the SCOPE clause of the Column definition.

class:

defined by:

multiplicity:

inverse:

NamedColumnSet
ColumnOptionsColumnSet::optionScopeColumnSet
zero or one
NamedColumnSet::optionScopeColumn

   Constraints

   The scale attribute is valid only if the precision attribute is specified. [C-3]