Class: Sequel::SQL::ColumnExpr

Inherits:
Expression show all
Defined in:
lib/sequel_core/sql.rb

Overview

Represents a generic column expression, used for specifying order and aliasing of columns.

Constant Summary

Constants included from ColumnMethods

Sequel::SQL::ColumnMethods::AS, Sequel::SQL::ColumnMethods::ASC, Sequel::SQL::ColumnMethods::DESC

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods inherited from Expression

#lit

Methods included from ColumnMethods

#as, #asc, #cast_as, #desc

Constructor Details

#initialize(l, op, r = nil) ⇒ ColumnExpr

Sets the attributes for the object to those given. The right (r) is not required, it is used when aliasing. The left (l) usually specifies the column name, and the operator (op) is usually 'ASC', 'DESC', or 'AS'.



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# File 'lib/sequel_core/sql.rb', line 81

def initialize(l, op, r = nil)
  @l, @op, @r = l, op, r
end

Instance Attribute Details

#l ⇒ Object (readonly)

Created readers for the left, operator, and right expression.



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# File 'lib/sequel_core/sql.rb', line 75

def l
  @l
end

#op ⇒ Object (readonly)

Created readers for the left, operator, and right expression.



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# File 'lib/sequel_core/sql.rb', line 75

def op
  @op
end

#r ⇒ Object (readonly)

Created readers for the left, operator, and right expression.



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# File 'lib/sequel_core/sql.rb', line 75

def r
  @r
end

Instance Method Details

#to_s(ds) ⇒ Object

Delegate the creation of the resulting SQL to the given dataset, since it may be database dependent.



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# File 'lib/sequel_core/sql.rb', line 87

def to_s(ds)
  ds.column_expr_sql(self)
end