module Crudboy::Concerns::GlobalDataDefinition
Public Instance Methods
Creates a new join table with the name created using the lexical order of the first two arguments. These arguments can be a String
or a Symbol.
# Creates a table called 'assemblies_parts' with no id. create_join_table(:assemblies, :parts)
You can pass an options
hash which can include the following keys:
:table_name
-
Sets the table name, overriding the default.
:column_options
-
Any extra options you want appended to the columns definition.
:options
-
Any extra options you want appended to the table definition.
:temporary
-
Make a temporary table.
:force
-
Set to true to drop the table before creating it. Defaults to false.
Note that create_join_table
does not create any indices by default; you can use its block form to do so yourself:
create_join_table :products, :categories do |t| t.index :product_id t.index :category_id end
Add a backend specific option to the generated SQL (MySQL)¶ ↑
create_join_table(:assemblies, :parts, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8')
generates:
CREATE TABLE assemblies_parts ( assembly_id bigint NOT NULL, part_id bigint NOT NULL, ) ENGINE=InnoDB DEFAULT CHARSET=utf8
# File lib/crudboy/concerns/global_data_definition.rb, line 203 def create_join_table(table_1, table_2, column_options: {}, **options) ActiveRecord::Base.connection.create_join_table(table_1, table_2, column_options, **options) end
Example:
create_table :post, id: false, primary_key: :id do |t| t.column :id, :bigint, precison: 19, comment: 'ID' t.column :name, :string, comment: '名称' t.column :gmt_created, :datetime, comment: '创建时间' t.column :gmt_modified, :datetime, comment: '最后修改时间' end
Creates a new table with the name table_name
. table_name
may either be a String
or a Symbol.
There are two ways to work with create_table
. You can use the block form or the regular form, like this:
Block form¶ ↑
# create_table() passes a TableDefinition object to the block. # This form will not only create the table, but also columns for the # table. create_table(:suppliers) do |t| t.column :name, :string, limit: 60 # Other fields here end
Block form, with shorthand¶ ↑
# You can also use the column types as method calls, rather than calling the column method. create_table(:suppliers) do |t| t.string :name, limit: 60 # Other fields here end
Regular form¶ ↑
# Creates a table called 'suppliers' with no columns. create_table(:suppliers) # Add a column to 'suppliers'. add_column(:suppliers, :name, :string, {limit: 60})
The options
hash can include the following keys:
:id
-
Whether to automatically add a primary key column. Defaults to true. Join tables for ActiveRecord::Base.has_and_belongs_to_many should set it to false.
A Symbol can be used to specify the type of the generated primary key column.
:primary_key
-
The name of the primary key, if one is to be added automatically. Defaults to
id
. If:id
is false, then this option is ignored.If an array is passed, a composite primary key will be created.
Note that Active Record models will automatically detect their primary key. This can be avoided by using self.primary_key= on the model to define the key explicitly.
:options
-
Any extra options you want appended to the table definition.
:temporary
-
Make a temporary table.
:force
-
Set to true to drop the table before creating it. Set to
:cascade
to drop dependent objects as well. Defaults to false. :if_not_exists
-
Set to true to avoid raising an error when the table already exists. Defaults to false.
:as
-
SQL to use to generate the table. When this option is used, the block is ignored, as are the
:id
and:primary_key
options.
Add a backend specific option to the generated SQL (MySQL)¶ ↑
create_table(:suppliers, options: 'ENGINE=InnoDB DEFAULT CHARSET=utf8mb4')
generates:
CREATE TABLE suppliers ( id bigint auto_increment PRIMARY KEY ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
Rename the primary key column¶ ↑
create_table(:objects, primary_key: 'guid') do |t| t.column :name, :string, limit: 80 end
generates:
CREATE TABLE objects ( guid bigint auto_increment PRIMARY KEY, name varchar(80) )
Change the primary key column type¶ ↑
create_table(:tags, id: :string) do |t| t.column :label, :string end
generates:
CREATE TABLE tags ( id varchar PRIMARY KEY, label varchar )
Create a composite primary key¶ ↑
create_table(:orders, primary_key: [:product_id, :client_id]) do |t| t.belongs_to :product t.belongs_to :client end
generates:
CREATE TABLE order ( product_id bigint NOT NULL, client_id bigint NOT NULL ); ALTER TABLE ONLY "orders" ADD CONSTRAINT orders_pkey PRIMARY KEY (product_id, client_id);
Do not add a primary key column¶ ↑
create_table(:categories_suppliers, id: false) do |t| t.column :category_id, :bigint t.column :supplier_id, :bigint end
generates:
CREATE TABLE categories_suppliers ( category_id bigint, supplier_id bigint )
Create a temporary table based on a query¶ ↑
create_table(:long_query, temporary: true, as: "SELECT * FROM orders INNER JOIN line_items ON order_id=orders.id")
generates:
CREATE TEMPORARY TABLE long_query AS SELECT * FROM orders INNER JOIN line_items ON order_id=orders.id
See also TableDefinition#column for details on how to create columns.
# File lib/crudboy/concerns/global_data_definition.rb, line 161 def create_table(table_name, **options, &blk) ActiveRecord::Base.connection.create_table(table_name, **options, &blk) end
Drops the join table specified by the given arguments. See create_join_table
for details.
Although this command ignores the block if one is given, it can be helpful to provide one in a migration's change
method so it can be reverted. In that case, the block will be used by create_join_table
.
# File lib/crudboy/concerns/global_data_definition.rb, line 229 def drop_join_table(table_1, table_2, **options) ActiveRecord::Base.connection.drop_join_table(table_1, table_2, **options) end
Drops a table from the database.
:force
-
Set to
:cascade
to drop dependent objects as well. Defaults to false. :if_exists
-
Set to
true
to only drop the table if it exists. Defaults to false.
Although this command ignores most options
and the block if one is given, it can be helpful to provide these in a migration's change
method so it can be reverted. In that case, options
and the block will be used by create_table
.
# File lib/crudboy/concerns/global_data_definition.rb, line 219 def drop_table(table_name, **options) ActiveRecord::Base.connection.drop_table(table_name, **options) end
Renames a table.
rename_table('octopuses', 'octopi')
# File lib/crudboy/concerns/global_data_definition.rb, line 237 def rename_table(table_name, new_name) ActiveRecord::Base.connection.rename_table(table_name, new_name) end