Class: ActiveRecord::ConnectionAdapters::Table

Inherits:
Object
  • Object
show all
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 SchemaStatements#create_table

Available transformations are:

change_table :table do |t|
  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.float
  t.decimal
  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

PostgreSQLAdapter::Table

Instance Method Summary collapse

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 350

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

Instance Method Details

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

Changes the column's definition according to the new options. See TableDefinition#column for details of the options you can use.

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

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 406

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

#change_default(column_name, default) ⇒ Object

Sets a new default value for a column. See SchemaStatements#change_column_default

t.change_default(:qualification, 'new')
t.change_default(:authorized, 1)

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 414

def change_default(column_name, default)
  @base.change_column_default(@table_name, column_name, default)
end

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

Adds a new column to the named table. See TableDefinition#column for details of the options you can use.

Creating a simple column
t.column(:name, :string)

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 360

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

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

Checks to see if a column exists. See SchemaStatements#column_exists?

Returns:

  • (Boolean)

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 365

def column_exists?(column_name, type = nil, options = {})
  @base.column_exists?(@table_name, column_name, type, options)
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. See SchemaStatements#add_index

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

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 378

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

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

Checks to see if an index exists. See SchemaStatements#index_exists?

Returns:

  • (Boolean)

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 383

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

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

Adds a reference. Optionally adds a type column, if :polymorphic option is provided. references and belongs_to are acceptable.

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

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 460

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

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 422

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

#remove_index(options = {}) ⇒ Object

Removes the given index from the table.

Remove the index_table_name_on_column in the table_name table
t.remove_index :column
Remove the index named index_table_name_on_branch_id in the table_name table
t.remove_index column: :branch_id
Remove the index named index_table_name_on_branch_id_and_party_id in the table_name table
t.remove_index column: [:branch_id, :party_id]
Remove the index named by_branch_party in the table_name table
t.remove_index name: :by_branch_party

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 436

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

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

Removes a reference. Optionally removes a type column. remove_references and remove_belongs_to are acceptable.

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

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 474

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

#remove_timestampsObject

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

t.remove_timestamps

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 443

def remove_timestamps
  @base.remove_timestamps(@table_name)
end

#rename(column_name, new_column_name) ⇒ Object

Renames a column.

t.rename(:description, :name)

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 450

def rename(column_name, new_column_name)
  @base.rename_column(@table_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)

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 390

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

#timestampsObject

Adds timestamps (created_at and updated_at) columns to the table. See SchemaStatements#add_timestamps

t.timestamps

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# File 'activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb', line 397

def timestamps
  @base.add_timestamps(@table_name)
end