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objectType column

the column

columnivoa:string column_nametapschema:TAPType datatypeivoa:string arraysizeivoa:string xtypeivoa:integer sizeivoa:string descriptionivoa:string utypeivoa:string unitivoa:string ucdivoa:integer indexedivoa:integer principalivoa:integer stdivoa:integer column_indexivoa:integer nullableivoa:boolean isNaturalKeytableFKColumncolumns1..*from_column1target_column1

    ## Members
name type mult description
column_name ivoa:string name of the column
datatype TAPType the type of the column (VOTable semantics)
arraysize ivoa:string optional the array size of the column
xtype ivoa:string optional the xtype of the column
size ivoa:integer optional deprecated in favour of arraysize
description ivoa:string optional a description of the column
utype ivoa:string optional the utype for the column
unit ivoa:string optional the unit for the column (taken from VOUnits)
ucd ivoa:string optional
indexed ivoa:integer does the column have an index
principal ivoa:integer indicates that the column is considered a core part of the content; clients can use this hint to make the principal column(s) visible, for example by selecting them by default in generating an ADQL query. In cases where the service selects the columns to return (such as a query language without an explicit output selection), the principal column indicates those columns that are returned by default
std ivoa:integer is the column defined by a standard
column_index ivoa:integer optional used to recommend table ordering for clients. Clients may order by index (ascending) so lower index items would appear earlier in a listing.
nullable ivoa:integer optional indicates whether the column may have null values
isNaturalKey ivoa:boolean optional indicates whether the column is a natural key (i.e. a key that has meaning outside the database)

References Detail

This is referred to byFKColumn

Containment

This is contained by table