Merge pull request #6913 from lexmag/column_exists_options

Add :default and :null options to column_exists? method

Examples:

    column_exists?(:testings, :taggable_id, :integer, null: false)
    column_exists?(:testings, :taggable_type, :string, default: 'Photo')

activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb

@@ -68,10 +68,12 @@ def columns(table_name) end
       #  column_exists?(:suppliers, :name, :string, :limit => 100)
       def column_exists?(table_name, column_name, type = nil, options = {})
         columns(table_name).any?{ |c| c.name == column_name.to_s &&
-                                      (!type                 || c.type == type) &&
-                                      (!options[:limit]      || c.limit == options[:limit]) &&
-                                      (!options[:precision]  || c.precision == options[:precision]) &&
-                                      (!options[:scale]      || c.scale == options[:scale]) }
+                                      (!type                     || c.type == type) &&
+                                      (!options.key?(:limit)     || c.limit == options[:limit]) &&
+                                      (!options.key?(:precision) || c.precision == options[:precision]) &&
+                                      (!options.key?(:scale)     || c.scale == options[:scale]) &&
+                                      (!options.key?(:default)   || c.default == options[:default]) &&
+                                      (!options.key?(:null)      || c.null == options[:null]) }
       end
 
       # Creates a new table with the name +table_name+. +table_name+ may either

activerecord/test/cases/migration/change_schema_test.rb

@@ -291,14 +291,20 @@ def test_column_exists_with_type
 
       def test_column_exists_with_definition
         connection.create_table :testings do |t|
-          t.column :foo, :string, :limit => 100
-          t.column :bar, :decimal, :precision => 8, :scale => 2
+          t.column :foo, :string, limit: 100
+          t.column :bar, :decimal, precision: 8, scale: 2
+          t.column :taggable_id, :integer, null: false 
+          t.column :taggable_type, :string, default: 'Photo'
         end
 
-        assert connection.column_exists?(:testings, :foo, :string, :limit => 100)
-        refute connection.column_exists?(:testings, :foo, :string, :limit => 50)
-        assert connection.column_exists?(:testings, :bar, :decimal, :precision => 8, :scale => 2)
-        refute connection.column_exists?(:testings, :bar, :decimal, :precision => 10, :scale => 2)
+        assert connection.column_exists?(:testings, :foo, :string, limit: 100)
+        refute connection.column_exists?(:testings, :foo, :string, limit: nil)
+        assert connection.column_exists?(:testings, :bar, :decimal, precision: 8, scale: 2)
+        refute connection.column_exists?(:testings, :bar, :decimal, precision: nil, scale: nil)
+        assert connection.column_exists?(:testings, :taggable_id, :integer, null: false)
+        refute connection.column_exists?(:testings, :taggable_id, :integer, null: true)
+        assert connection.column_exists?(:testings, :taggable_type, :string, default: 'Photo')
+        refute connection.column_exists?(:testings, :taggable_type, :string, default: nil)
       end
 
       def test_column_exists_on_table_with_no_options_parameter_supplied