Class: Veritas::SQL::Generator::Relation::Unary

Inherits:
Veritas::SQL::Generator::Relation show all
Extended by:
Aliasable
Includes:
Direction, Function::Aggregate, Function::Connective, Function::Numeric, Function::Predicate, Function::Proposition, Function::String, Literal
Defined in:
lib/veritas/sql/generator/relation/unary.rb

Overview

Generates an SQL statement for a unary relation

Direct Known Subclasses

Base

Constant Summary collapse

DISTINCT = 
'DISTINCT '.freeze
NO_ROWS = 
' HAVING FALSE'.freeze
ANY_ROWS = 
' HAVING COUNT (*) > 0'
COLLAPSIBLE = 
{
  Algebra::Summarization                => Set[                                                                                                                                                                                                                                                               ].freeze,
  Algebra::Projection                   => Set[ Algebra::Projection,                                      Algebra::Restriction,                                                                                                                                                                               ].freeze,
  Algebra::Extension                    => Set[ Algebra::Projection,                                      Algebra::Restriction,                         Veritas::Relation::Operation::Order, Veritas::Relation::Operation::Reverse, Veritas::Relation::Operation::Offset, Veritas::Relation::Operation::Limit ].freeze,
  Algebra::Rename                       => Set[ Algebra::Projection,                                      Algebra::Restriction,                         Veritas::Relation::Operation::Order, Veritas::Relation::Operation::Reverse, Veritas::Relation::Operation::Offset, Veritas::Relation::Operation::Limit ].freeze,
  Algebra::Restriction                  => Set[ Algebra::Projection,                                                                                    Veritas::Relation::Operation::Order, Veritas::Relation::Operation::Reverse,                                                                           ].freeze,
  Veritas::Relation::Operation::Order   => Set[ Algebra::Projection, Algebra::Extension, Algebra::Rename, Algebra::Restriction, Algebra::Summarization, Veritas::Relation::Operation::Order, Veritas::Relation::Operation::Reverse,                                                                           ].freeze,
  Veritas::Relation::Operation::Reverse => Set[ Algebra::Projection, Algebra::Extension, Algebra::Rename, Algebra::Restriction, Algebra::Summarization, Veritas::Relation::Operation::Order, Veritas::Relation::Operation::Reverse,                                                                           ].freeze,
  Veritas::Relation::Operation::Offset  => Set[ Algebra::Projection, Algebra::Extension, Algebra::Rename, Algebra::Restriction, Algebra::Summarization, Veritas::Relation::Operation::Order, Veritas::Relation::Operation::Reverse,                                                                           ].freeze,
  Veritas::Relation::Operation::Limit   => Set[ Algebra::Projection, Algebra::Extension, Algebra::Rename, Algebra::Restriction, Algebra::Summarization, Veritas::Relation::Operation::Order, Veritas::Relation::Operation::Reverse, Veritas::Relation::Operation::Offset,                                     ].freeze,
}.freeze

Constants included from Direction

Direction::DESC

Constants included from Identifier

Identifier::ESCAPED_QUOTE, Identifier::QUOTE

Constants included from Literal

Literal::ESCAPED_QUOTE, Literal::FALSE, Literal::NULL, Literal::QUOTE, Literal::SEPARATOR, Literal::TIME_SCALE, Literal::TRUE

Constants included from Function::Aggregate

Function::Aggregate::COUNT, Function::Aggregate::MAXIMUM, Function::Aggregate::MEAN, Function::Aggregate::MINIMUM, Function::Aggregate::STANDARD_DEVIATION, Function::Aggregate::SUM, Function::Aggregate::VARIANCE

Constants included from Function::Connective

Function::Connective::AND, Function::Connective::NOT, Function::Connective::OR

Constants included from Function::Predicate

Function::Predicate::BETWEEN, Function::Predicate::EMPTY_ARRAY, Function::Predicate::EQUAL_TO, Function::Predicate::EQUAL_TO_NULL, Function::Predicate::GREATER_THAN, Function::Predicate::GREATER_THAN_OR_EQUAL_TO, Function::Predicate::IN, Function::Predicate::LESS_THAN, Function::Predicate::LESS_THAN_OR_EQUAL_TO, Function::Predicate::NOT_BETWEEN, Function::Predicate::NOT_EQUAL_TO, Function::Predicate::NOT_EQUAL_TO_NULL, Function::Predicate::NOT_IN

Constants included from Function::String

Function::String::LENGTH

Constants included from Function::Numeric

Function::Numeric::ABSOLUTE, Function::Numeric::ADD, Function::Numeric::DIVIDE, Function::Numeric::MOD, Function::Numeric::MULTIPLY, Function::Numeric::POWER, Function::Numeric::SQUARE_ROOT, Function::Numeric::SUBTRACT

Constants inherited from Veritas::SQL::Generator::Relation

EMPTY_HASH, EMPTY_STRING, SEPARATOR, STAR

Constants inherited from Visitor

Visitor::DOUBLE_COLON, Visitor::NAME_REP, Visitor::NAME_SEP_REGEXP, Visitor::UNDERSCORE

Instance Attribute Summary

Attributes inherited from Veritas::SQL::Generator::Relation

#name

Instance Method Summary collapse

Methods included from Direction

#visit_veritas_relation_operation_order_ascending, #visit_veritas_relation_operation_order_descending

Methods included from Attribute

#visit_veritas_attribute

Methods included from Identifier

#visit_identifier

Methods included from Literal

dup_frozen, #visit_class, #visit_date, #visit_date_time, #visit_enumerable, #visit_false_class, #visit_nil_class, #visit_numeric, #visit_string, #visit_time, #visit_true_class

Methods included from Function::Aggregate

#visit_veritas_aggregate_count, #visit_veritas_aggregate_maximum, #visit_veritas_aggregate_mean, #visit_veritas_aggregate_minimum, #visit_veritas_aggregate_standard_deviation, #visit_veritas_aggregate_sum, #visit_veritas_aggregate_variance

Methods included from Function::Connective

#visit_veritas_function_connective_conjunction, #visit_veritas_function_connective_disjunction, #visit_veritas_function_connective_negation

Methods included from Function::Predicate

#visit_veritas_function_predicate_equality, #visit_veritas_function_predicate_exclusion, #visit_veritas_function_predicate_greater_than, #visit_veritas_function_predicate_greater_than_or_equal_to, #visit_veritas_function_predicate_inclusion, #visit_veritas_function_predicate_inequality, #visit_veritas_function_predicate_less_than, #visit_veritas_function_predicate_less_than_or_equal_to

Methods included from Function::Proposition

#visit_veritas_function_proposition_contradiction, #visit_veritas_function_proposition_tautology

Methods included from Function::String

#visit_veritas_function_string_length

Methods included from Function::Numeric

#visit_veritas_function_numeric_absolute, #visit_veritas_function_numeric_addition, #visit_veritas_function_numeric_division, #visit_veritas_function_numeric_exponentiation, #visit_veritas_function_numeric_modulo, #visit_veritas_function_numeric_multiplication, #visit_veritas_function_numeric_square_root, #visit_veritas_function_numeric_subtraction, #visit_veritas_function_numeric_unary_minus, #visit_veritas_function_numeric_unary_plus

Methods inherited from Veritas::SQL::Generator::Relation

#to_s, #to_sql, #to_subquery, #visit, visit, #visited?

Methods inherited from Visitor

handler_for, #visit, #visited?

Constructor Details

#initialize ⇒ undefined

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Initialize a Unary relation SQL generator



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 42

def initialize
  super
  @scope = ::Set.new
end

Instance Method Details

#visit_veritas_algebra_extension(extension) ⇒ self

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Visit an Extension



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 85

def visit_veritas_algebra_extension(extension)
  @from      = subquery_for(extension)
  @header    = extension.header
  @columns ||= columns_for(extension.operand)
  add_extensions(extension.extensions)
  scope_query(extension)
  self
end

#visit_veritas_algebra_projection(projection) ⇒ self

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Visit a Projection



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 69

def visit_veritas_algebra_projection(projection)
  @from     = subquery_for(projection)
  @distinct = DISTINCT
  @header   = projection.header
  @columns  = columns_for(projection)
  scope_query(projection)
  self
end

#visit_veritas_algebra_rename(rename) ⇒ self

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Visit a Rename



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 101

def visit_veritas_algebra_rename(rename)
  @from    = subquery_for(rename)
  @header  = rename.header
  @columns = columns_for(rename.operand, rename.aliases.to_hash)
  scope_query(rename)
  self
end

#visit_veritas_algebra_restriction(restriction) ⇒ self

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Visit a Restriction



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 116

def visit_veritas_algebra_restriction(restriction)
  @from      = subquery_for(restriction)
  @where     = " WHERE #{dispatch(restriction.predicate)}"
  @header    = restriction.header
  @columns ||= columns_for(restriction)
  scope_query(restriction)
  self
end

#visit_veritas_algebra_summarization(summarization) ⇒ self

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Visit a Summarization



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 132

def visit_veritas_algebra_summarization(summarization)
  summarize_per = summarization.summarize_per
  @from         = subquery_for(summarization)
  @header       = summarization.header
  @columns      = columns_for(summarize_per)
  summarize_per(summarize_per)
  group_by_columns
  add_extensions(summarization.summarizers)
  scope_query(summarization)
  self
end

#visit_veritas_relation_base(base_relation) ⇒ self

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Visit a Base Relation



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 54

def visit_veritas_relation_base(base_relation)
  @name    = base_relation.name
  @from    = visit_identifier(@name)
  @header  = base_relation.header
  @columns = columns_for(base_relation)
  self
end

#visit_veritas_relation_operation_limit(limit) ⇒ self

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Visit a Limit



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 167

def visit_veritas_relation_operation_limit(limit)
  @from      = subquery_for(limit)
  @limit     = " LIMIT #{limit.limit}"
  @header    = limit.header
  @columns ||= columns_for(limit)
  scope_query(limit)
  self
end

#visit_veritas_relation_operation_offset(offset) ⇒ self

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Visit an Offset



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 183

def visit_veritas_relation_operation_offset(offset)
  @from      = subquery_for(offset)
  @offset    = " OFFSET #{offset.offset}"
  @header    = offset.header
  @columns ||= columns_for(offset)
  scope_query(offset)
  self
end

#visit_veritas_relation_operation_order(order) ⇒ self

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Visit an Order



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# File 'lib/veritas/sql/generator/relation/unary.rb', line 151

def visit_veritas_relation_operation_order(order)
  @from      = subquery_for(order)
  @order     = " ORDER BY #{order_for(order.directions)}"
  @header    = order.header
  @columns ||= columns_for(order)
  scope_query(order)
  self
end