added full_text_select method - the ability to add a full_text query …

…to the select statement.

lib/sequel/adapters/shared/mysql.rb

@@ -188,8 +188,34 @@ def distinct(*columns)
         super
       end
 
-      # MySQL specific full text search syntax.
+      # Adds full text search in WHERE clause
       def full_text_search(cols, terms, opts = {})
+        filter(full_text_sql(cols, terms, opts))
+      end
+
+      # Adds full text search in SELECT clause
+      def full_text_select(cols, terms, opts = {})
+        # You must provide the :as argument to opts
+        as = opts[:as] || raise(Error, "Must provide :as option")
+
+        # Sequel defines * to be default select options if none have
+        # been previously defined.  We will be defining a select
+        # for full_text, so we need to add back the * if it
+        # hasn't already been removed by a custom select
+        orig_select = (@opts[:select].nil? || @opts[:select].empty?) ?
+          Sequel::Dataset::WILDCARD.lit : nil
+
+        # Select more will add the select given to the already created
+        # selects.  If none have been given it will be *, MATCH..AS.
+        # Otherwise, select what has previously been declared and add
+        # the full_text MATCH to it
+        select_more(
+          *[orig_select,full_text_sql(cols,terms,opts).lit.as(as)].compact
+        )
+      end
+
+      # MySQL specific full text search syntax.
+      def full_text_sql(cols, terms, opts = {})
         mode = opts[:boolean] ? " IN BOOLEAN MODE" : ""
         s = if Array === terms
           if mode.empty?
@@ -200,7 +226,7 @@ def full_text_search(cols, terms, opts = {})
         else
           "MATCH #{literal(Array(cols))} AGAINST (#{literal(terms)}#{mode})"
         end
-        filter(s)
+        s
       end
 
       # MySQL allows HAVING clause on ungrouped datasets.

spec/adapters/mysql_spec.rb

@@ -612,7 +612,7 @@ def MYSQL_DB.ret_commit
     ]
   end
 
-  specify "should support full_text_search" do
+  specify "should support full_text_search in WHERE clause" do
     MYSQL_DB[:posts].full_text_search(:title, 'ruby').sql.should ==
       "SELECT * FROM posts WHERE (MATCH (title) AGAINST ('ruby'))"
 
@@ -622,6 +622,21 @@ def MYSQL_DB.ret_commit
     MYSQL_DB[:posts].full_text_search(:title, '+ruby -rails', :boolean => true).sql.should ==
       "SELECT * FROM posts WHERE (MATCH (title) AGAINST ('+ruby -rails' IN BOOLEAN MODE))"
   end
+
+  specify "should support full_text_search in SELECT CLAUSE" do
+    # Should add full_text_search to * when select is not defined
+    MYSQL_DB[:posts].full_text_select(:title, 'ruby', :as => :score).sql.should ==
+      "SELECT *, MATCH (title) AGAINST ('ruby') AS score FROM posts"
+
+    # Should add full_text_search to custom select
+    MYSQL_DB[:posts].select(:title).full_text_select(:title, 'ruby', :as => :score).sql.should ==
+      "SELECT title, MATCH (title) AGAINST ('ruby') AS score FROM posts"
+
+    # Should raise Error when :as option is not provided
+    lambda { 
+      MYSQL_DB[:posts].full_text_select(:title, 'ruby').sql
+    }.should raise_error(Sequel::Error)
+  end
 
   specify "should support spatial indexes" do
     g = Sequel::Schema::Generator.new(MYSQL_DB) do