Class: ActiveRecord::ConnectionAdapters::Table

Inherits:
Object
  • Object
show all
Includes:
ColumnMethods
Defined in:
activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb

Overview

Represents an SQL table in an abstract way for updating a table. Also see TableDefinition and connection.create_table

Available transformations are:

change_table :table do |t|
  t.primary_key
  t.column
  t.index
  t.rename_index
  t.timestamps
  t.change
  t.change_default
  t.rename
  t.references
  t.belongs_to
  t.string
  t.text
  t.integer
  t.bigint
  t.float
  t.decimal
  t.numeric
  t.datetime
  t.timestamp
  t.time
  t.date
  t.binary
  t.boolean
  t.remove
  t.remove_references
  t.remove_belongs_to
  t.remove_index
  t.remove_timestamps
end

Direct Known Subclasses

MySQL::Table, PostgreSQL::Table

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from ColumnMethods

#primary_key

Constructor Details

#initialize(table_name, base) ⇒ Table

Returns a new instance of Table.


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 465

def initialize(table_name, base)
  @name = table_name
  @base = base
end

Instance Attribute Details

#nameObject (readonly)

Returns the value of attribute name


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 463

def name
  @name
end

Instance Method Details

#change(column_name, type, options = {}) ⇒ Object

Changes the column's definition according to the new options.

t.change(:name, :string, limit: 80)
t.change(:description, :text)

See TableDefinition#column for details of the options you can use.


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 535

def change(column_name, type, options = {})
  @base.change_column(name, column_name, type, options)
end

#change_default(column_name, default_or_changes) ⇒ Object

Sets a new default value for a column.

t.change_default(:qualification, 'new')
t.change_default(:authorized, 1)
t.change_default(:status, from: nil, to: "draft")

See connection.change_column_default


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 546

def change_default(column_name, default_or_changes)
  @base.change_column_default(name, column_name, default_or_changes)
end

#column(column_name, type, options = {}) ⇒ Object

Adds a new column to the named table.

t.column(:name, :string)

See TableDefinition#column for details of the options you can use.


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 475

def column(column_name, type, options = {})
  @base.add_column(name, column_name, type, options)
end

#column_exists?(column_name, type = nil, options = {}) ⇒ Boolean

Checks to see if a column exists.

t.string(:name) unless t.column_exists?(:name, :string)

See connection.column_exists?

Returns:

  • (Boolean)

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 484

def column_exists?(column_name, type = nil, options = {})
  @base.column_exists?(name, column_name, type, options)
end

#foreign_key(*args) ⇒ Object

Adds a foreign key.

t.foreign_key(:authors)

See connection.add_foreign_key


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 622

def foreign_key(*args) # :nodoc:
  @base.add_foreign_key(name, *args)
end

#foreign_key_exists?(*args) ⇒ Boolean

Checks to see if a foreign key exists.

t.foreign_key(:authors) unless t.foreign_key_exists?(:authors)

See connection.foreign_key_exists?

Returns:

  • (Boolean)

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 631

def foreign_key_exists?(*args) # :nodoc:
  @base.foreign_key_exists?(name, *args)
end

#index(column_name, options = {}) ⇒ Object

Adds a new index to the table. column_name can be a single Symbol, or an Array of Symbols.

t.index(:name)
t.index([:branch_id, :party_id], unique: true)
t.index([:branch_id, :party_id], unique: true, name: 'by_branch_party')

See connection.add_index for details of the options you can use.


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 496

def index(column_name, options = {})
  @base.add_index(name, column_name, options)
end

#index_exists?(column_name, options = {}) ⇒ Boolean

Checks to see if an index exists.

unless t.index_exists?(:branch_id)

t.index(:branch_id)

end

See connection.index_exists?

Returns:

  • (Boolean)

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 507

def index_exists?(column_name, options = {})
  @base.index_exists?(name, column_name, options)
end

#references(*args) ⇒ Object Also known as: belongs_to

Adds a reference.

t.references(:user)
t.belongs_to(:supplier, foreign_key: true)

See connection.add_reference for details of the options you can use.


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 595

def references(*args)
  options = args.extract_options!
  args.each do |ref_name|
    @base.add_reference(name, ref_name, options)
  end
end

#remove(*column_names) ⇒ Object

Removes the column(s) from the table definition.

t.remove(:qualification)
t.remove(:qualification, :experience)

See connection.remove_columns


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 556

def remove(*column_names)
  @base.remove_columns(name, *column_names)
end

#remove_index(options = {}) ⇒ Object

Removes the given index from the table.

t.remove_index(:branch_id)
t.remove_index(column: [:branch_id, :party_id])
t.remove_index(name: :by_branch_party)

See connection.remove_index


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 567

def remove_index(options = {})
  @base.remove_index(name, options)
end

#remove_references(*args) ⇒ Object Also known as: remove_belongs_to

Removes a reference. Optionally removes a type column.

t.remove_references(:user)
t.remove_belongs_to(:supplier, polymorphic: true)

See connection.remove_reference


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 609

def remove_references(*args)
  options = args.extract_options!
  args.each do |ref_name|
    @base.remove_reference(name, ref_name, options)
  end
end

#remove_timestamps(options = {}) ⇒ Object

Removes the timestamp columns (created_at and updated_at) from the table.

t.remove_timestamps

See connection.remove_timestamps


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 576

def remove_timestamps(options = {})
  @base.remove_timestamps(name, options)
end

#rename(column_name, new_column_name) ⇒ Object

Renames a column.

t.rename(:description, :name)

See connection.rename_column


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 585

def rename(column_name, new_column_name)
  @base.rename_column(name, column_name, new_column_name)
end

#rename_index(index_name, new_index_name) ⇒ Object

Renames the given index on the table.

t.rename_index(:user_id, :account_id)

See connection.rename_index


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 516

def rename_index(index_name, new_index_name)
  @base.rename_index(name, index_name, new_index_name)
end

#timestamps(options = {}) ⇒ Object

Adds timestamps (created_at and updated_at) columns to the table.

t.timestamps(null: false)

See connection.add_timestamps


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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 525

def timestamps(options = {})
  @base.add_timestamps(name, options)
end