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
- B
- C
- I
- N
- R
- T
[R] | name |
Changes the column's definition according to the new options.
t.change(:name, :string, limit: 80)
t.change(:description, :text)
See ActiveRecord::ConnectionAdapters::TableDefinition#column for details of the options you can use.
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")
Adds a new column to the named table.
t.column(:name, :string)
See ActiveRecord::ConnectionAdapters::TableDefinition#column for details of the options you can use.
Checks to see if a column exists.
t.string(:name) unless t.column_exists?(:name, :string)
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.
Checks to see if an index exists.
unless t.index_exists?(:branch_id)
t.index(:branch_id)
end
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.
Removes the column(s) from the table definition.
t.remove(:qualification)
t.remove(:qualification, :experience)
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)
Removes a reference. Optionally removes a type
column.
t.remove_references(:user)
t.remove_belongs_to(:supplier, polymorphic: true)
Removes the timestamp columns (created_at
and
updated_at
) from the table.
t.remove_timestamps
Renames the given index on the table.
t.rename_index(:user_id, :account_id)
Adds timestamps (created_at
and updated_at
)
columns to the table.
t.timestamps(null: false)