Method: ActiveRecord::ConnectionAdapters::SchemaStatements#create_table

Defined in:
lib/active_record/connection_adapters/abstract/schema_statements.rb

#create_table(table_name, options = {}) {|td| ... } ⇒ Object

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, => 60)

The options hash can include the following keys: [:id] Whether to automatically add a primary key column. Defaults to true. Join tables for has_and_belongs_to_many should set it to false. [:primary_key] The name of the primary key, if one is to be added automatically. Defaults to id. If :id is false this option is ignored.

Also note that this just sets the primary key in the table. You additionally
need to configure the primary key in the model via +self.primary_key=+.
Models do NOT auto-detect the primary key from their table 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.

Examples
Add a backend specific option to the generated SQL (MySQL)

create_table(:suppliers, :options => 'ENGINE=InnoDB DEFAULT CHARSET=utf8') generates: CREATE TABLE suppliers ( id int(11) DEFAULT NULL auto_increment PRIMARY KEY ) ENGINE=InnoDB DEFAULT CHARSET=utf8

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 int(11) DEFAULT NULL auto_increment PRIMARY KEY, name varchar(80) )

Do not add a primary key column

create_table(:categories_suppliers, :id => false) do |t| t.column :category_id, :integer t.column :supplier_id, :integer end generates: CREATE TABLE categories_suppliers ( category_id int, supplier_id int )

See also TableDefinition#column for details on how to create columns.

Yields:

  • (td) 


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# File 'lib/active_record/connection_adapters/abstract/schema_statements.rb', line 156

def create_table(table_name, options = {})
  td = table_definition
  td.primary_key(options[:primary_key] || Base.get_primary_key(table_name.to_s.singularize)) unless options[:id] == false

  yield td if block_given?

  if options[:force] && table_exists?(table_name)
    drop_table(table_name, options)
  end

  create_sql = "CREATE#{' TEMPORARY' if options[:temporary]} TABLE "
  create_sql << "#{quote_table_name(table_name)} ("
  create_sql << td.to_sql
  create_sql << ") #{options[:options]}"
  execute create_sql
end