Class: RnDB::Table
Instance Attribute Summary collapse
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#id ⇒ Object
readonly
Returns the value of attribute id.
Class Method Summary collapse
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.[](index) ⇒ Object
Return a new record corresponding to the specified index.
-
.all ⇒ Object
Return all records.
-
.association(attribute, *args) ⇒ Object
Add an association between two Table models.
-
.column(attribute, *args) ⇒ Object
Add a new column to the Table model.
-
.count ⇒ Object
Count all records, delegating this to the all Query.
-
.each(&block) ⇒ Object
Iterate over all records, delegating this to the all Query.
- .get(attribute) ⇒ Object
-
.join(id, name) ⇒ Object
Return the instance joined to the current ID.
-
.key(id, attribute) ⇒ Object
Retrieve the key that can be queried on for generated attributes.
-
.last ⇒ Object
Return the last record, to be consistent with #first, which we get by magic.
-
.pluck(*args) ⇒ Object
Pluck specified attributes from all records, delegating this to the all query.
-
.rand(*args) ⇒ Object
Generate a random number, intended to be used in lambdas.
-
.sample(limit = 1) ⇒ Object
Return a Querty that contains a random sampling of records.
-
.table_name ⇒ Object
Return the name of the table, which is derived from the class name.
-
.value(id, attribute) ⇒ Object
Retrieve the value of the given attribute for the given ID.
-
.where(constraints = {}) ⇒ Object
Return a Query that matches the supplied constraints.
Instance Method Summary collapse
-
#attributes ⇒ Object
Generate all attributes, which may be expensive.
-
#initialize(id) ⇒ Table
constructor
Create a new record wit the given ID.
-
#to_h ⇒ Object
Return the attributes as a hash.
-
#to_s ⇒ Object
Return a stringified version of the attributes hash.
Constructor Details
#initialize(id) ⇒ Table
Create a new record wit the given ID.
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# File 'lib/rndb/table.rb', line 10 def initialize(id) _validate! @id = id end |
Instance Attribute Details
#id ⇒ Object (readonly)
Returns the value of attribute id.
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# File 'lib/rndb/table.rb', line 7 def id @id end |
Class Method Details
.[](index) ⇒ Object
Return a new record corresponding to the specified index.
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# File 'lib/rndb/table.rb', line 79 def [](index) _validate! new(index) if index < count end |
.all ⇒ Object
Return all records.
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# File 'lib/rndb/table.rb', line 91 def all where end |
.association(attribute, *args) ⇒ Object
Add an association between two Table models.
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# File 'lib/rndb/table.rb', line 149 def association(attribute, *args) args.each do |arg| _schema[:associations][attribute] = arg end define_method("#{attribute}_id".to_sym) do _generate_association_id(attribute) end define_method(attribute) do _generate_association(attribute) end end |
.column(attribute, *args) ⇒ Object
Add a new column to the Table model.
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# File 'lib/rndb/table.rb', line 121 def column(attribute, *args) column = _schema[:columns][attribute] args.each do |arg| index = case arg when Hash, Array :distribution when Proc :generator else raise "unsupported column parameter" end column[index] = arg end if column[:generator] && column[:distribution] define_method("#{attribute}_key") do _generate_column_key(attribute) end end define_method(attribute) do _generate_column(attribute) end define_method("#{attribute}=".to_sym) do |value| self.class.send(:_set_state, id, attribute, value) end end |
.count ⇒ Object
Count all records, delegating this to the all Query.
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# File 'lib/rndb/table.rb', line 96 def count all.count end |
.each(&block) ⇒ Object
Iterate over all records, delegating this to the all Query
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# File 'lib/rndb/table.rb', line 106 def each(&block) all.each(&block) end |
.get(attribute) ⇒ Object
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# File 'lib/rndb/table.rb', line 210 def get(attribute) raise unless @current if _schema[:columns].key?(attribute) value(@current, attribute) elsif _schema[:associations].key?(attribute) join(@current, attribute) else raise "no such attribute" end end |
.join(id, name) ⇒ Object
Return the instance joined to the current ID.
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# File 'lib/rndb/table.rb', line 201 def join(id, name) @current = id _schema[:associations][name].each do |context| next unless (index = where(context[:where]).index(id)) return where(context[:joins])[index] end nil end |
.key(id, attribute) ⇒ Object
Retrieve the key that can be queried on for generated attributes.
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# File 'lib/rndb/table.rb', line 169 def key(id, attribute) @current = id _validate! column = _schema[:columns][attribute] return if column[:distribution].nil? column[:mapping].find do |_, ids| ids.include?(id) end&.first end |
.last ⇒ Object
Return the last record, to be consistent with #first, which we get by magic.
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# File 'lib/rndb/table.rb', line 101 def last all.last end |
.pluck(*args) ⇒ Object
Pluck specified attributes from all records, delegating this to the all query.
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# File 'lib/rndb/table.rb', line 111 def pluck(*args) all.pluck(args) end |
.rand(*args) ⇒ Object
Generate a random number, intended to be used in lambdas. The number will have been seeded appropriately to ensure determinism.
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# File 'lib/rndb/table.rb', line 163 def rand(*args) _validate! _db.prng.rand(*args) end |
.sample(limit = 1) ⇒ Object
Return a Querty that contains a random sampling of records.
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# File 'lib/rndb/table.rb', line 116 def sample(limit=1) all.sample(limit) end |
.table_name ⇒ Object
Return the name of the table, which is derived from the class name.
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# File 'lib/rndb/table.rb', line 74 def table_name name.downcase.to_sym end |
.value(id, attribute) ⇒ Object
Retrieve the value of the given attribute for the given ID.
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# File 'lib/rndb/table.rb', line 180 def value(id, attribute) @current = id _validate! return id if attribute == :id override = _get_state(id, attribute) return override unless override.nil? column = _schema[:columns][attribute] value = key(id, attribute) unless column[:generator].nil? _seed_prng(id, attribute) value = if column[:distribution].nil? column[:generator].call else column[:generator].call(value) end end value end |
.where(constraints = {}) ⇒ Object
Return a Query that matches the supplied constraints
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# File 'lib/rndb/table.rb', line 85 def where(constraints={}) _validate! Query.new(self, _query(constraints, _schema[:size])) end |
Instance Method Details
#attributes ⇒ Object
Generate all attributes, which may be expensive.
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# File 'lib/rndb/table.rb', line 16 def attributes _generate_all end |
#to_h ⇒ Object
Return the attributes as a hash.
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# File 'lib/rndb/table.rb', line 21 def to_h attributes end |
#to_s ⇒ Object
Return a stringified version of the attributes hash.
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# File 'lib/rndb/table.rb', line 26 def to_s to_h.to_s end |