Class: ROM::SQL::Schema

Inherits:
ROM::Schema
  • Object
show all
Defined in:
lib/rom/sql/schema.rb,
lib/rom/sql/schema/dsl.rb,
lib/rom/sql/schema/inferrer.rb,
lib/rom/sql/schema/index_dsl.rb,
lib/rom/sql/schema/type_builder.rb,
lib/rom/sql/schema/attributes_inferrer.rb

Overview

Specialized schema for SQL databases

Defined Under Namespace

Classes: AttributesInferrer, DSL, IndexDSL, Inferrer, TypeBuilder

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#foreign_keys ⇒ Array<ForeignKey> (readonly)

Returns Array with foreign keys.

Returns:



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# File 'lib/rom/sql/schema.rb', line 25

option :foreign_keys, default: -> { EMPTY_SET }

#indexes ⇒ Array<Index> (readonly)

Returns Array with schema indexes.

Returns:

  • (Array<Index>) —

    Array with schema indexes



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# File 'lib/rom/sql/schema.rb', line 21

option :indexes, default: -> { EMPTY_SET }

Instance Method Details

#call(relation) ⇒ Relation

Create a new relation based on the schema definition

Parameters:

  • relation (Relation) —

    The source relation

Returns:



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# File 'lib/rom/sql/schema.rb', line 142

def call(relation)
  relation.new(relation.dataset.select(*qualified_projection), schema: self)
end

#empty ⇒ Schema

Return an empty schema

Returns:



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# File 'lib/rom/sql/schema.rb', line 151

def empty
  new(EMPTY_ARRAY)
end

#finalize_attributes!(**options) ⇒ Object

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.

Finalize all attributes by qualifying them and initializing primary key names



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# File 'lib/rom/sql/schema.rb', line 158

def finalize_attributes!(**options)
  super do
    @attributes = map(&:qualified)
  end
end

#group(&block) ⇒ Mixed

Open Group DSL for setting GROUP BY clause in queries

Returns:

  • (Mixed) —

    Result of the block call

See Also:



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# File 'lib/rom/sql/schema.rb', line 56

def group(&block)
  GroupDSL.new(self).call(&block)
end

#join(other) ⇒ Schema

Join with another schema

Parameters:

  • other (Schema) —

    The other schema to join with

Returns:



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# File 'lib/rom/sql/schema.rb', line 122

def join(other)
  merge(other.joined)
end

#joined ⇒ Schema

Return a new schema with all attributes marked as joined

Returns:



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# File 'lib/rom/sql/schema.rb', line 131

def joined
  new(map(&:joined))
end

#order(&block) ⇒ Mixed

Open Order DSL for setting ORDER clause in queries

Returns:

  • (Mixed) —

    Result of the block call

See Also:



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# File 'lib/rom/sql/schema.rb', line 45

def order(&block)
  OrderDSL.new(self).call(&block)
end

#project(*names, &block) ⇒ Schema

Project a schema

Returns:

  • (Schema) —

    A new schema with projected attributes

See Also:



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# File 'lib/rom/sql/schema.rb', line 89

def project(*names, &block)
  if block
    super(*(names + ProjectionDSL.new(self).(&block)))
  else
    super
  end
end

#project_fk(mapping) ⇒ Schema

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.

Project schema so that it only contains renamed foreign key

Returns:



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# File 'lib/rom/sql/schema.rb', line 111

def project_fk(mapping)
  new(rename(mapping).map(&:foreign_key))
end

#project_pk ⇒ Schema

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.

Project schema so that it only contains primary key

Returns:



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# File 'lib/rom/sql/schema.rb', line 102

def project_pk
  project(*primary_key_names)
end

#qualified(table_alias = nil) ⇒ Schema

Return a new schema with attributes marked as qualified

Returns:



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# File 'lib/rom/sql/schema.rb', line 65

def qualified(table_alias = nil)
  new(map { |attr| attr.qualified(table_alias) })
end

#qualified_projection(table_alias = nil) ⇒ Schema

Return a new schema with attributes that are aliased and marked as qualified

Intended to be used when passing attributes to dataset#select

Returns:



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# File 'lib/rom/sql/schema.rb', line 77

def qualified_projection(table_alias = nil)
  new(map { |attr| attr.qualified_projection(table_alias) })
end

#restriction(&block) ⇒ Mixed

Open restriction DSL for defining query conditions using schema attributes

Returns:

  • (Mixed) —

    Result of the block call

See Also:



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# File 'lib/rom/sql/schema.rb', line 34

def restriction(&block)
  RestrictionDSL.new(self).call(&block)
end