Merge pull request #14766 from eric-chahin/migration_bug

Changed change_column in PG schema_statements.rb to make sure that the u...

activerecord/lib/active_record/connection_adapters/postgresql/quoting.rb

@@ -182,6 +182,15 @@ def quoted_date(value) #:nodoc:
           end
           result
         end
+
+        # Does not quote function default values for UUID columns
+        def quote_default_value(value, column) #:nodoc:
+          if column.type == :uuid && value =~ /\(\)/
+            value
+          else 
+            quote(value)
+          end
+        end
       end
     end
   end

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

@@ -187,6 +187,10 @@ def columns(table_name)
           end
         end
 
+        def column_for(table_name, column_name) #:nodoc:
+          columns(table_name).detect { |c| c.name == column_name.to_s } 
+        end
+
         # Returns the current database name.
         def current_database
           query('select current_database()', 'SCHEMA')[0][0]
@@ -404,13 +408,15 @@ def change_column(table_name, column_name, type, options = {})
         # Changes the default value of a table column.
         def change_column_default(table_name, column_name, default)
           clear_cache!
-          execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT #{quote(default)}"
+          column = column_for(table_name, column_name)
+          execute "ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT #{quote_default_value(default, column)}" if column
         end
 
         def change_column_null(table_name, column_name, null, default = nil)
           clear_cache!
           unless null || default.nil?
-            execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
+            column = column_for(table_name, column_name)
+            execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote_default_value(default, column)} WHERE #{quote_column_name(column_name)} IS NULL") if column
           end
           execute("ALTER TABLE #{quote_table_name(table_name)} ALTER #{quote_column_name(column_name)} #{null ? 'DROP' : 'SET'} NOT NULL")
         end

activerecord/test/cases/adapters/postgresql/uuid_test.rb

@@ -40,6 +40,19 @@ class UUIDType < ActiveRecord::Base
     drop_table "uuid_data_type"
   end
 
+  def test_change_column_default
+    @connection.add_column :uuid_data_type, :thingy, :uuid, null: false, default: "uuid_generate_v1()"
+    UUIDType.reset_column_information
+    column = UUIDType.columns.find { |c| c.name == 'thingy' }
+    assert_equal "uuid_generate_v1()", column.default_function
+    
+    @connection.change_column :uuid_data_type, :thingy, :uuid, null: false, default: "uuid_generate_v4()"
+    
+    UUIDType.reset_column_information
+    column = UUIDType.columns.find { |c| c.name == 'thingy' }
+    assert_equal "uuid_generate_v4()", column.default_function
+  end
+
   def test_data_type_of_uuid_types
     column = UUIDType.columns_hash["guid"]
     assert_equal :uuid, column.type