Module: ActiveRecord::ModelSchema::ClassMethods
- Defined in:
- lib/active_record/model_schema.rb
Instance Method Summary collapse
-
#_default_attributes ⇒ Object
:nodoc:.
-
#attributes_builder ⇒ Object
:nodoc:.
-
#column_defaults ⇒ Object
Returns a hash where the keys are column names and the values are default values when instantiating the AR object for this table.
-
#column_names ⇒ Object
Returns an array of column names as strings.
-
#column_types ⇒ Object
:nodoc:.
-
#content_columns ⇒ Object
Returns an array of column objects where the primary id, all columns ending in “_id” or “_count”, and columns used for single table inheritance have been removed.
-
#full_table_name_prefix ⇒ Object
:nodoc:.
-
#full_table_name_suffix ⇒ Object
:nodoc:.
-
#inheritance_column ⇒ Object
Defines the name of the table column which will store the class name on single-table inheritance situations.
-
#inheritance_column=(value) ⇒ Object
Sets the value of inheritance_column.
-
#quoted_table_name ⇒ Object
Returns a quoted version of the table name, used to construct SQL statements.
-
#reset_column_information ⇒ Object
Resets all the cached information about columns, which will cause them to be reloaded on the next request.
-
#reset_sequence_name ⇒ Object
:nodoc:.
-
#reset_table_name ⇒ Object
Computes the table name, (re)sets it internally, and returns it.
- #sequence_name ⇒ Object
-
#sequence_name=(value) ⇒ Object
Sets the name of the sequence to use when generating ids to the given value, or (if the value is nil or false) to the value returned by the given block.
-
#table_exists? ⇒ Boolean
Indicates whether the table associated with this class exists.
-
#table_name ⇒ Object
Guesses the table name (in forced lower-case) based on the name of the class in the inheritance hierarchy descending directly from ActiveRecord::Base.
-
#table_name=(value) ⇒ Object
Sets the table name explicitly.
-
#type_for_attribute(attr_name) ⇒ Object
:nodoc:.
Instance Method Details
#_default_attributes ⇒ Object
:nodoc:
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# File 'lib/active_record/model_schema.rb', line 253 def _default_attributes # :nodoc: @default_attributes ||= attributes_builder.build_from_database( raw_default_values) end |
#attributes_builder ⇒ Object
:nodoc:
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# File 'lib/active_record/model_schema.rb', line 233 def attributes_builder # :nodoc: @attributes_builder ||= AttributeSet::Builder.new(column_types, primary_key) end |
#column_defaults ⇒ Object
Returns a hash where the keys are column names and the values are default values when instantiating the AR object for this table.
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# File 'lib/active_record/model_schema.rb', line 249 def column_defaults _default_attributes.to_hash end |
#column_names ⇒ Object
Returns an array of column names as strings.
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# File 'lib/active_record/model_schema.rb', line 259 def column_names @column_names ||= columns.map { |column| column.name } end |
#column_types ⇒ Object
:nodoc:
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# File 'lib/active_record/model_schema.rb', line 237 def column_types # :nodoc: @column_types ||= columns_hash.transform_values(&:cast_type).tap do |h| h.default = Type::Value.new end end |
#content_columns ⇒ Object
Returns an array of column objects where the primary id, all columns ending in “_id” or “_count”, and columns used for single table inheritance have been removed.
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# File 'lib/active_record/model_schema.rb', line 265 def content_columns @content_columns ||= columns.reject { |c| c.name == primary_key || c.name =~ /(_id|_count)$/ || c.name == inheritance_column } end |
#full_table_name_prefix ⇒ Object
:nodoc:
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# File 'lib/active_record/model_schema.rb', line 169 def full_table_name_prefix #:nodoc: (parents.detect{ |p| p.respond_to?(:table_name_prefix) } || self).table_name_prefix end |
#full_table_name_suffix ⇒ Object
:nodoc:
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# File 'lib/active_record/model_schema.rb', line 173 def full_table_name_suffix #:nodoc: (parents.detect {|p| p.respond_to?(:table_name_suffix) } || self).table_name_suffix end |
#inheritance_column ⇒ Object
Defines the name of the table column which will store the class name on single-table inheritance situations.
The default inheritance column name is type
, which means it’s a reserved word inside Active Record. To be able to use single-table inheritance with another column name, or to use the column type
in your own model for something else, you can set inheritance_column
:
self.inheritance_column = 'zoink'
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# File 'lib/active_record/model_schema.rb', line 186 def inheritance_column (@inheritance_column ||= nil) || superclass.inheritance_column end |
#inheritance_column=(value) ⇒ Object
Sets the value of inheritance_column
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# File 'lib/active_record/model_schema.rb', line 191 def inheritance_column=(value) @inheritance_column = value.to_s @explicit_inheritance_column = true end |
#quoted_table_name ⇒ Object
Returns a quoted version of the table name, used to construct SQL statements.
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# File 'lib/active_record/model_schema.rb', line 154 def quoted_table_name @quoted_table_name ||= connection.quote_table_name(table_name) end |
#reset_column_information ⇒ Object
Resets all the cached information about columns, which will cause them to be reloaded on the next request.
The most common usage pattern for this method is probably in a migration, when just after creating a table you want to populate it with some default values, eg:
class CreateJobLevels < ActiveRecord::Migration
def up
create_table :job_levels do |t|
t.integer :id
t.string :name
t.
end
JobLevel.reset_column_information
%w{assistant executive manager director}.each do |type|
JobLevel.create(name: type)
end
end
def down
drop_table :job_levels
end
end
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# File 'lib/active_record/model_schema.rb', line 295 def reset_column_information connection.clear_cache! undefine_attribute_methods connection.schema_cache.clear_table_cache!(table_name) @arel_engine = nil @column_names = nil @column_types = nil @content_columns = nil @default_attributes = nil @inheritance_column = nil unless defined?(@explicit_inheritance_column) && @explicit_inheritance_column @relation = nil end |
#reset_sequence_name ⇒ Object
:nodoc:
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# File 'lib/active_record/model_schema.rb', line 204 def reset_sequence_name #:nodoc: @explicit_sequence_name = false @sequence_name = connection.default_sequence_name(table_name, primary_key) end |
#reset_table_name ⇒ Object
Computes the table name, (re)sets it internally, and returns it.
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# File 'lib/active_record/model_schema.rb', line 159 def reset_table_name #:nodoc: self.table_name = if abstract_class? superclass == Base ? nil : superclass.table_name elsif superclass.abstract_class? superclass.table_name || compute_table_name else compute_table_name end end |
#sequence_name ⇒ Object
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# File 'lib/active_record/model_schema.rb', line 196 def sequence_name if base_class == self @sequence_name ||= reset_sequence_name else (@sequence_name ||= nil) || base_class.sequence_name end end |
#sequence_name=(value) ⇒ Object
Sets the name of the sequence to use when generating ids to the given value, or (if the value is nil or false) to the value returned by the given block. This is required for Oracle and is useful for any database which relies on sequences for primary key generation.
If a sequence name is not explicitly set when using Oracle, it will default to the commonly used pattern of: ##table_name_seq
If a sequence name is not explicitly set when using PostgreSQL, it will discover the sequence corresponding to your primary key for you.
class Project < ActiveRecord::Base
self.sequence_name = "projectseq" # default would have been "project_seq"
end
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# File 'lib/active_record/model_schema.rb', line 223 def sequence_name=(value) @sequence_name = value.to_s @explicit_sequence_name = true end |
#table_exists? ⇒ Boolean
Indicates whether the table associated with this class exists
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# File 'lib/active_record/model_schema.rb', line 229 def table_exists? connection.schema_cache.table_exists?(table_name) end |
#table_name ⇒ Object
Guesses the table name (in forced lower-case) based on the name of the class in the inheritance hierarchy descending directly from ActiveRecord::Base. So if the hierarchy looks like: Reply < Message < ActiveRecord::Base, then Message is used to guess the table name even when called on Reply. The rules used to do the guess are handled by the Inflector class in Active Support, which knows almost all common English inflections. You can add new inflections in config/initializers/inflections.rb.
Nested classes are given table names prefixed by the singular form of the parent’s table name. Enclosing modules are not considered.
Examples
class Invoice < ActiveRecord::Base
end
file class table_name
invoice.rb Invoice invoices
class Invoice < ActiveRecord::Base
class Lineitem < ActiveRecord::Base
end
end
file class table_name
invoice.rb Invoice::Lineitem invoice_lineitems
module Invoice
class Lineitem < ActiveRecord::Base
end
end
file class table_name
invoice/lineitem.rb Invoice::Lineitem lineitems
Additionally, the class-level table_name_prefix
is prepended and the table_name_suffix
is appended. So if you have “myapp_” as a prefix, the table name guess for an Invoice class becomes “myapp_invoices”. Invoice::Lineitem becomes “myapp_invoice_lineitems”.
You can also set your own table name explicitly:
class Mouse < ActiveRecord::Base
self.table_name = "mice"
end
Alternatively, you can override the table_name method to define your own computation. (Possibly using super
to manipulate the default table name.) Example:
class Post < ActiveRecord::Base
def self.table_name
"special_" + super
end
end
Post.table_name # => "special_posts"
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# File 'lib/active_record/model_schema.rb', line 125 def table_name reset_table_name unless defined?(@table_name) @table_name end |
#table_name=(value) ⇒ Object
Sets the table name explicitly. Example:
class Project < ActiveRecord::Base
self.table_name = "project"
end
You can also just define your own self.table_name
method; see the documentation for ActiveRecord::Base#table_name.
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# File 'lib/active_record/model_schema.rb', line 138 def table_name=(value) value = value && value.to_s if defined?(@table_name) return if value == @table_name reset_column_information if connected? end @table_name = value @quoted_table_name = nil @arel_table = nil @sequence_name = nil unless defined?(@explicit_sequence_name) && @explicit_sequence_name @relation = Relation.create(self, arel_table) end |
#type_for_attribute(attr_name) ⇒ Object
:nodoc:
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# File 'lib/active_record/model_schema.rb', line 243 def type_for_attribute(attr_name) # :nodoc: column_types[attr_name] end |