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.change_null
t.rename
t.references
t.belongs_to
t.check_constraint
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.blob
t.boolean
t.foreign_key
t.json
t.virtual
t.remove
t.remove_foreign_key
t.remove_references
t.remove_belongs_to
t.remove_index
t.remove_check_constraint
t.remove_timestamps
end
- B
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Attributes
[R] | name |
Class Public methods
new(table_name, base) Link
Instance Public methods
change(column_name, type, **options) Link
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.
change_default(column_name, default_or_changes) Link
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")
change_null(column_name, null, default = nil) Link
Sets or removes a NOT NULL constraint on a column.
t.change_null(:qualification, true)
t.change_null(:qualification, false, 0)
check_constraint(*args, **options) Link
Adds a check constraint.
t.check_constraint("price > 0", name: "price_check")
column(column_name, type, index: nil, **options) Link
Adds a new column to the named table.
t.column(:name, :string)
See TableDefinition#column
for details of the options you can use.
# File activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 632 def column(column_name, type, index: nil, **options) @base.add_column(name, column_name, type, **options) if index index_options = index.is_a?(Hash) ? index : {} index(column_name, **index_options) end end
column_exists?(column_name, type = nil, **options) Link
Checks to see if a column exists.
t.string(:name) unless t.column_exists?(:name, :string)
foreign_key(*args, **options) Link
Adds a foreign key to the table using a supplied table name.
t.foreign_key(:authors)
t.foreign_key(:authors, column: :author_id, primary_key: "id")
foreign_key_exists?(*args, **options) Link
Checks to see if a foreign key exists.
t.foreign_key(:authors) unless t.foreign_key_exists?(:authors)
index(column_name, **options) Link
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.
index_exists?(column_name, **options) Link
Checks to see if an index exists.
unless t.index_exists?(:branch_id)
t.index(:branch_id)
end
references(*args, **options) Link
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.
remove(*column_names, **options) Link
Removes the column(s) from the table definition.
t.remove(:qualification)
t.remove(:qualification, :experience)
remove_check_constraint(*args, **options) Link
Removes the given check constraint from the table.
t.remove_check_constraint(name: "price_check")
remove_foreign_key(*args, **options) Link
Removes the given foreign key from the table.
t.remove_foreign_key(:authors)
t.remove_foreign_key(column: :author_id)
remove_index(column_name = nil, **options) Link
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)
t.remove_index(:branch_id, name: :by_branch_party)
remove_references(*args, **options) Link
Removes a reference. Optionally removes a type
column.
t.remove_references(:user)
t.remove_belongs_to(:supplier, polymorphic: true)
remove_timestamps(**options) Link
Removes the timestamp columns (created_at
and updated_at
) from the table.
t.remove_timestamps
rename(column_name, new_column_name) Link
rename_index(index_name, new_index_name) Link
Renames the given index on the table.
t.rename_index(:user_id, :account_id)
timestamps(**options) Link
Adds timestamps (created_at
and updated_at
) columns to the table.
t.timestamps(null: false)