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-rw-r--r--lib/arel/nodes.rb1
-rw-r--r--lib/arel/nodes/count.rb12
-rw-r--r--lib/arel/nodes/sql_literal.rb3
-rw-r--r--lib/arel/visitors/to_sql.rb4
-rw-r--r--spec/arel/nodes/sql_literal_spec.rb19
5 files changed, 39 insertions, 0 deletions
diff --git a/lib/arel/nodes.rb b/lib/arel/nodes.rb
index 67568b5fd4..98fc045690 100644
--- a/lib/arel/nodes.rb
+++ b/lib/arel/nodes.rb
@@ -3,6 +3,7 @@ require 'arel/nodes/equality'
require 'arel/nodes/or'
require 'arel/nodes/in'
+require 'arel/nodes/count'
require 'arel/nodes/sql_literal'
require 'arel/nodes/select_core'
require 'arel/nodes/select_statement'
diff --git a/lib/arel/nodes/count.rb b/lib/arel/nodes/count.rb
new file mode 100644
index 0000000000..b7c4b60948
--- /dev/null
+++ b/lib/arel/nodes/count.rb
@@ -0,0 +1,12 @@
+module Arel
+ module Nodes
+ class Count
+ attr_accessor :expressions, :distinct
+
+ def initialize expr, distinct = false
+ @expressions = expr
+ @distinct = distinct
+ end
+ end
+ end
+end
diff --git a/lib/arel/nodes/sql_literal.rb b/lib/arel/nodes/sql_literal.rb
index 53ff376071..526d088449 100644
--- a/lib/arel/nodes/sql_literal.rb
+++ b/lib/arel/nodes/sql_literal.rb
@@ -1,6 +1,9 @@
module Arel
module Nodes
class SqlLiteral < String
+ def count distinct = false
+ Count.new [self], distinct
+ end
end
end
end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 55ed53177e..05c33ddb8b 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -58,6 +58,10 @@ module Arel
].compact.join ' '
end
+ def visit_Arel_Nodes_Count o
+ "COUNT(#{o.distinct ? 'DISTINCT ' : ''}#{o.expressions.map { |x| visit x }.join(', ')})"
+ end
+
def visit_Arel_Nodes_TableAlias o
"#{visit o.relation} #{quote_table_name o.name}"
end
diff --git a/spec/arel/nodes/sql_literal_spec.rb b/spec/arel/nodes/sql_literal_spec.rb
new file mode 100644
index 0000000000..390eb708e1
--- /dev/null
+++ b/spec/arel/nodes/sql_literal_spec.rb
@@ -0,0 +1,19 @@
+module Arel
+ module Nodes
+ describe 'sql literal' do
+ describe 'count' do
+ it 'makes a count node' do
+ node = SqlLiteral.new('*').count
+ viz = Visitors::ToSql.new Table.engine
+ viz.accept(node).should be_like %{ COUNT(*) }
+ end
+
+ it 'makes a distinct node' do
+ node = SqlLiteral.new('*').count true
+ viz = Visitors::ToSql.new Table.engine
+ viz.accept(node).should be_like %{ COUNT(DISTINCT *) }
+ end
+ end
+ end
+ end
+end