SqlColumn

Representation of COUNT aggregation

Representation of a derived column

Used to represent columns on the outside of subqueries and common table expressions. Note that column aliases are tracked across derivation so that derived columns will continue to refer to the same underlying data irrespective of renaming.

Representation of a column of an embedded subobject

Columns of embedded subobjects have a different context path from columns of their enclosing object, however they resolve to columns of the same SqlSelect. To satisfy the SqlSelect invariant that all its columns must share the same context path we have to wrap the embedded column so that its context path conforms.

Representation of a synthetic null column

Primarily used to pad the disjuncts of an SqlUnion.

Representation of a window aggregation

Representation of a scalar subquery

Representation of a column of a table/view