Method: Sequel::Database#schema

Defined in:
lib/sequel/database/schema_sql.rb

#schema(table = nil, opts = {}) ⇒ Object

Parse the schema from the database. If the table_name is not given, returns the schema for all tables as a hash. If the table_name is given, returns the schema for a single table as an array with all members being arrays of length 2. Available options are:

  • :reload - Get fresh information from the database, instead of using cached information. If table_name is blank, :reload should be used unless you are sure that schema has not been called before with a table_name, otherwise you may only getting the schemas for tables that have been requested explicitly.

  • :schema - An explicit schema to use. It may also be implicitly provided via the table name.

Raises:



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# File 'lib/sequel/database/schema_sql.rb', line 220

def schema(table = nil, opts={})
  Deprecation.deprecate('Calling Database#schema without a table argument', 'Use database.tables.inject({}){|h, m| h[m] = database.schema(m); h}') unless table
  raise(Error, 'schema parsing is not implemented on this database') unless respond_to?(:schema_parse_table, true)

  if table
    sch, table_name = schema_and_table(table)
    quoted_name = quote_schema_table(table)
  end
  opts = opts.merge(:schema=>sch) if sch && !opts.include?(:schema)
  if opts[:reload] && @schemas
    if table_name
      @schemas.delete(quoted_name)
    else
      @schemas = nil
    end
  end

  if @schemas
    if table_name
      return @schemas[quoted_name] if @schemas[quoted_name]
    else
      return @schemas
    end
  end
  
  raise(Error, '#tables does not exist, you must provide a specific table to #schema') if table.nil? && !respond_to?(:tables, true)

  @schemas ||= Hash.new do |h,k|
    quote_name = quote_schema_table(k)
    h[quote_name] if h.include?(quote_name)
  end

  if table_name
    cols = schema_parse_table(table_name, opts)
    raise(Error, 'schema parsing returned no columns, table probably doesn\'t exist') if cols.nil? || cols.empty?
    @schemas[quoted_name] = cols
  else
    tables.each{|t| @schemas[quote_schema_table(t)] = schema_parse_table(t.to_s, opts)}
    @schemas
  end
end