Merge pull request #370 from joshk/unrolled_map.

favor map over each in mysql* adapters

activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb

@@ -411,11 +411,9 @@ def collation
       end
 
       def tables(name = nil)
-        tables = []
-        execute("SHOW TABLES", 'SCHEMA').each do |field|
-          tables << field.first
+        execute("SHOW TABLES", 'SCHEMA').collect do |field|
+          field.first
         end
-        tables
       end
 
       def drop_table(table_name, options = {})

activerecord/lib/active_record/connection_adapters/mysql_adapter.rb

@@ -560,9 +560,8 @@ def collation
       end
 
       def tables(name = nil, database = nil) #:nodoc:
-        tables = []
         result = execute(["SHOW TABLES", database].compact.join(' IN '), 'SCHEMA')
-        result.each { |field| tables << field[0] }
+        tables = result.collect { |field| field[0] }
         result.free
         tables
       end
@@ -607,9 +606,8 @@ def indexes(table_name, name = nil)#:nodoc:
       # Returns an array of +MysqlColumn+ objects for the table specified by +table_name+.
       def columns(table_name, name = nil)#:nodoc:
         sql = "SHOW FIELDS FROM #{quote_table_name(table_name)}"
-        columns = []
         result = execute(sql, 'SCHEMA')
-        result.each { |field| columns << MysqlColumn.new(field[0], field[4], field[1], field[2] == "YES") }
+        columns = result.collect { |field| MysqlColumn.new(field[0], field[4], field[1], field[2] == "YES") }
         result.free
         columns
       end