Allow HAVING to take multiple conditions, like WHERE

lib/arel/select_manager.rb

@@ -97,10 +97,8 @@ module Arel
       self
     end
 
-    def having expr
-      expr = Nodes::SqlLiteral.new(expr) if String === expr
-
-      @ctx.having = Nodes::Having.new(expr)
+    def having *exprs
+      @ctx.having = Nodes::Having.new(collapse(exprs, @ctx.having))
       self
     end
 
@@ -211,16 +209,22 @@ switch to `compile_insert`
     end
 
     private
-    def collapse exprs
-      return exprs.first if exprs.length == 1
-
-      create_and exprs.compact.map { |expr|
+    def collapse exprs, existing = nil
+      exprs = exprs.unshift(existing.expr) if existing
+      exprs = exprs.compact.map { |expr|
         if String === expr
+          # FIXME: Don't do this automatically
           Arel.sql(expr)
         else
           expr
         end
       }
+
+      if exprs.length == 1
+        exprs.first
+      else
+        create_and exprs
+      end
     end
   end
 end

test/test_select_manager.rb

@@ -99,13 +99,28 @@ module Arel
         end
       end
 
-      describe '#having' do
+      describe 'having' do
         it 'converts strings to SQLLiterals' do
           table   = Table.new :users
           mgr = table.from table
           mgr.having 'foo'
           mgr.to_sql.must_be_like %{ SELECT FROM "users" HAVING foo }
         end
+
+        it 'can have multiple items specified separately' do
+          table = Table.new :users
+          mgr = table.from table
+          mgr.having 'foo'
+          mgr.having 'bar'
+          mgr.to_sql.must_be_like %{ SELECT FROM "users" HAVING foo AND bar }
+        end
+
+        it 'can have multiple items specified together' do
+          table = Table.new :users
+          mgr = table.from table
+          mgr.having 'foo', 'bar'
+          mgr.to_sql.must_be_like %{ SELECT FROM "users" HAVING foo AND bar }
+        end
       end
     end