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pg, `PostgreSQL::Name` to hold schema qualified names.

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senny committed May 30, 2014
1 parent 6963e33 commit 7b8d95d58fbadf71e1f27a848427de27e0a2742a
@@ -150,12 +150,7 @@ def quote_string(s) #:nodoc:
# - "schema.name".table_name
# - "schema.name"."table.name"
def quote_table_name(name)
- schema, table = Utils.extract_schema_and_table(name.to_s)
- if schema
- "#{quote_column_name(schema)}.#{quote_column_name(table)}"
- else
- quote_column_name(table)
- end
+ Utils.extract_schema_qualified_name(name.to_s).quoted
end
def quote_table_name_for_assignment(table, attr)
@@ -97,16 +97,16 @@ def tables(name = nil)
# If the schema is not specified as part of +name+ then it will only find tables within
# the current schema search path (regardless of permissions to access tables in other schemas)
def table_exists?(name)
- schema, table = Utils.extract_schema_and_table(name.to_s)
- return false unless table
+ name = Utils.extract_schema_qualified_name(name.to_s)
+ return false unless name.identifier
exec_query(<<-SQL, 'SCHEMA').rows.first[0].to_i > 0
SELECT COUNT(*)
FROM pg_class c
LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('r','v','m') -- (r)elation/table, (v)iew, (m)aterialized view
- AND c.relname = '#{table.gsub(/(^"|"$)/,'')}'
- AND n.nspname = #{schema ? "'#{schema}'" : 'ANY (current_schemas(false))'}
+ AND c.relname = '#{name.identifier}'
+ AND n.nspname = #{name.schema ? "'#{name.schema}'" : 'ANY (current_schemas(false))'}
SQL
end
@@ -1,23 +1,64 @@
module ActiveRecord
module ConnectionAdapters
module PostgreSQL
+ # Value Object to hold a schema qualified name.
+ # This is usually the name of a PostgreSQL relation but it can also represent
+ # schema qualified type names. +schema+ and +identifier+ are unquoted to prevent
+ # double quoting.
+ class Name # :nodoc:
+ SEPARATOR = "."
+ attr_reader :schema, :identifier
+
+ def initialize(schema, identifier)
+ @schema, @identifier = unquote(schema), unquote(identifier)
+ end
+
+ def to_s
+ parts.join SEPARATOR
+ end
+
+ def quoted
+ parts.map { |p| PGconn.quote_ident(p) }.join SEPARATOR
+ end
+
+ def ==(o)
+ o.class == self.class && o.parts == parts
+ end
+ alias_method :eql?, :==
+
+ def hash
+ parts.hash
+ end
+
+ protected
+ def unquote(part)
+ return unless part
+ part.gsub(/(^"|"$)/,'')
+ end
+
+ def parts
+ @parts ||= [@schema, @identifier].compact
+ end
+ end
+
module Utils # :nodoc:
extend self
- # Returns an array of <tt>[schema_name, table_name]</tt> extracted from +name+.
- # +schema_name+ is nil if not specified in +name+.
- # +schema_name+ and +table_name+ exclude surrounding quotes (regardless of whether provided in +name+)
- # +name+ supports the range of schema/table references understood by PostgreSQL, for example:
+ # Returns an instance of <tt>ActiveRecord::ConnectionAdapters::PostgreSQL::Name</tt>
+ # extracted from +string+.
+ # +schema+ is nil if not specified in +string+.
+ # +schema+ and +identifier+ exclude surrounding quotes (regardless of whether provided in +string+)
+ # +string+ supports the range of schema/table references understood by PostgreSQL, for example:
#
# * <tt>table_name</tt>
# * <tt>"table.name"</tt>
# * <tt>schema_name.table_name</tt>
# * <tt>schema_name."table.name"</tt>
# * <tt>"schema_name".table_name</tt>
# * <tt>"schema.name"."table name"</tt>
- def extract_schema_and_table(name)
- table, schema = name.scan(/[^".\s]+|"[^"]*"/)[0..1].collect{|m| m.gsub(/(^"|"$)/,'') }.reverse
- [schema, table]
+ def extract_schema_qualified_name(string)
+ table, schema = string.scan(/[^".\s]+|"[^"]*"/)[0..1].reverse
+ PostgreSQL::Name.new(schema, table)
end
end
end
@@ -1,9 +1,10 @@
require 'cases/helper'
class PostgreSQLUtilsTest < ActiveSupport::TestCase
+ Name = ActiveRecord::ConnectionAdapters::PostgreSQL::Name
include ActiveRecord::ConnectionAdapters::PostgreSQL::Utils
- def test_extract_schema_and_table
+ def test_extract_schema_qualified_name
{
%(table_name) => [nil,'table_name'],
%("table.name") => [nil,'table.name'],
@@ -14,7 +15,47 @@ def test_extract_schema_and_table
%("even spaces".table) => ['even spaces','table'],
%(schema."table.name") => ['schema', 'table.name']
}.each do |given, expect|
- assert_equal expect, extract_schema_and_table(given)
+ assert_equal Name.new(*expect), extract_schema_qualified_name(given)
end
end
end
+
+class PostgreSQLNameTest < ActiveSupport::TestCase
+ Name = ActiveRecord::ConnectionAdapters::PostgreSQL::Name
+
+ test "represents itself as schema.name" do
+ obj = Name.new("public", "articles")
+ assert_equal "public.articles", obj.to_s
+ end
+
+ test "without schema, represents itself as name only" do
+ obj = Name.new(nil, "articles")
+ assert_equal "articles", obj.to_s
+ end
+
+ test "quoted returns a string representation usable in a query" do
+ assert_equal %("articles"), Name.new(nil, "articles").quoted
+ assert_equal %("public"."articles"), Name.new("public", "articles").quoted
+ end
+
+ test "prevents double quoting" do
+ name = Name.new('"quoted_schema"', '"quoted_table"')
+ assert_equal "quoted_schema.quoted_table", name.to_s
+ assert_equal %("quoted_schema"."quoted_table"), name.quoted
+ end
+
+ test "equality based on state" do
+ assert_equal Name.new("access", "users"), Name.new("access", "users")
+ assert_equal Name.new(nil, "users"), Name.new(nil, "users")
+ assert_not_equal Name.new(nil, "users"), Name.new("access", "users")
+ assert_not_equal Name.new("access", "users"), Name.new("public", "users")
+ assert_not_equal Name.new("public", "users"), Name.new("public", "articles")
+ end
+
+ test "can be used as hash key" do
+ hash = {Name.new("schema", "article_seq") => "success"}
+ assert_equal "success", hash[Name.new("schema", "article_seq")]
+ assert_equal nil, hash[Name.new("schema", "articles")]
+ assert_equal nil, hash[Name.new("public", "article_seq")]
+ end
+end

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