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-rw-r--r--lib/arel/nodes.rb2
-rw-r--r--lib/arel/nodes/limit.rb7
-rw-r--r--lib/arel/nodes/select_core.rb3
-rw-r--r--lib/arel/nodes/top.rb6
-rw-r--r--lib/arel/select_manager.rb5
-rw-r--r--lib/arel/visitors.rb3
-rw-r--r--lib/arel/visitors/mssql.rb16
-rw-r--r--lib/arel/visitors/mysql.rb2
-rw-r--r--lib/arel/visitors/sqlite.rb2
-rw-r--r--lib/arel/visitors/to_sql.rb15
-rw-r--r--test/visitors/test_mssql.rb18
-rw-r--r--test/visitors/test_to_sql.rb2
12 files changed, 73 insertions, 8 deletions
diff --git a/lib/arel/nodes.rb b/lib/arel/nodes.rb
index c454152d0d..db2f22750a 100644
--- a/lib/arel/nodes.rb
+++ b/lib/arel/nodes.rb
@@ -24,6 +24,8 @@ require 'arel/nodes/function'
require 'arel/nodes/count'
require 'arel/nodes/values'
require 'arel/nodes/offset'
+require 'arel/nodes/limit'
+require 'arel/nodes/top'
require 'arel/nodes/sum'
require 'arel/nodes/exists'
require 'arel/nodes/max'
diff --git a/lib/arel/nodes/limit.rb b/lib/arel/nodes/limit.rb
new file mode 100644
index 0000000000..68ea95daf5
--- /dev/null
+++ b/lib/arel/nodes/limit.rb
@@ -0,0 +1,7 @@
+module Arel
+ module Nodes
+ class Limit < Arel::Nodes::Unary
+ end
+ end
+end
+
diff --git a/lib/arel/nodes/select_core.rb b/lib/arel/nodes/select_core.rb
index acc6bb9815..501a2aaf7c 100644
--- a/lib/arel/nodes/select_core.rb
+++ b/lib/arel/nodes/select_core.rb
@@ -1,10 +1,11 @@
module Arel
module Nodes
class SelectCore < Arel::Nodes::Node
- attr_accessor :froms, :projections, :wheres, :groups
+ attr_accessor :top, :froms, :projections, :wheres, :groups
attr_accessor :having
def initialize
+ @top = nil
@froms = nil
@projections = []
@wheres = []
diff --git a/lib/arel/nodes/top.rb b/lib/arel/nodes/top.rb
new file mode 100644
index 0000000000..56e2e97e8d
--- /dev/null
+++ b/lib/arel/nodes/top.rb
@@ -0,0 +1,6 @@
+module Arel
+ module Nodes
+ class Top < Arel::Nodes::Unary
+ end
+ end
+end
diff --git a/lib/arel/select_manager.rb b/lib/arel/select_manager.rb
index 10d23378ae..cb656d5340 100644
--- a/lib/arel/select_manager.rb
+++ b/lib/arel/select_manager.rb
@@ -10,7 +10,7 @@ module Arel
end
def taken
- @ast.limit
+ @ast.limit && @ast.limit.expr
end
def constraints
@@ -131,7 +131,8 @@ module Arel
end
def take limit
- @ast.limit = limit
+ @ast.limit = Nodes::Limit.new(limit)
+ @ctx.top = Nodes::Top.new(limit)
self
end
diff --git a/lib/arel/visitors.rb b/lib/arel/visitors.rb
index 2b0a06d534..8410b2b912 100644
--- a/lib/arel/visitors.rb
+++ b/lib/arel/visitors.rb
@@ -4,6 +4,7 @@ require 'arel/visitors/to_sql'
require 'arel/visitors/sqlite'
require 'arel/visitors/postgresql'
require 'arel/visitors/mysql'
+require 'arel/visitors/mssql'
require 'arel/visitors/oracle'
require 'arel/visitors/join_sql'
require 'arel/visitors/where_sql'
@@ -16,6 +17,8 @@ module Arel
'postgresql' => Arel::Visitors::PostgreSQL,
'mysql' => Arel::Visitors::MySQL,
'mysql2' => Arel::Visitors::MySQL,
+ 'mssql' => Arel::Visitors::MSSQL,
+ 'sqlserver' => Arel::Visitors::MSSQL,
'oracle_enhanced' => Arel::Visitors::Oracle,
'sqlite' => Arel::Visitors::SQLite,
'sqlite3' => Arel::Visitors::SQLite,
diff --git a/lib/arel/visitors/mssql.rb b/lib/arel/visitors/mssql.rb
new file mode 100644
index 0000000000..9b0e77c19b
--- /dev/null
+++ b/lib/arel/visitors/mssql.rb
@@ -0,0 +1,16 @@
+module Arel
+ module Visitors
+ class MSSQL < Arel::Visitors::ToSql
+ private
+
+ def visit_Arel_Nodes_Limit o
+ ""
+ end
+
+ def visit_Arel_Nodes_Top o
+ "TOP #{visit o.expr}"
+ end
+
+ end
+ end
+end
diff --git a/lib/arel/visitors/mysql.rb b/lib/arel/visitors/mysql.rb
index ace8fb0979..b37d76f710 100644
--- a/lib/arel/visitors/mysql.rb
+++ b/lib/arel/visitors/mysql.rb
@@ -10,7 +10,7 @@ module Arel
# :'(
# http://dev.mysql.com/doc/refman/5.0/en/select.html#id3482214
def visit_Arel_Nodes_SelectStatement o
- o.limit = 18446744073709551615 if o.offset && !o.limit
+ o.limit = Arel::Nodes::Limit.new(18446744073709551615) if o.offset && !o.limit
super
end
diff --git a/lib/arel/visitors/sqlite.rb b/lib/arel/visitors/sqlite.rb
index c45160851d..237ae913bb 100644
--- a/lib/arel/visitors/sqlite.rb
+++ b/lib/arel/visitors/sqlite.rb
@@ -3,7 +3,7 @@ module Arel
class SQLite < Arel::Visitors::ToSql
private
def visit_Arel_Nodes_SelectStatement o
- o.limit = -1 if o.offset && !o.limit
+ o.limit = Arel::Nodes::Limit.new(-1) if o.offset && !o.limit
super
end
end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index a2105d7043..7435e41561 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -76,7 +76,7 @@ module Arel
[
o.cores.map { |x| visit_Arel_Nodes_SelectCore x }.join,
("ORDER BY #{o.orders.map { |x| visit x }.join(', ')}" unless o.orders.empty?),
- ("LIMIT #{visit o.limit}" if o.limit),
+ (visit(o.limit) if o.limit),
(visit(o.offset) if o.offset),
(visit(o.lock) if o.lock),
].compact.join ' '
@@ -84,7 +84,9 @@ module Arel
def visit_Arel_Nodes_SelectCore o
[
- "SELECT #{o.projections.map { |x| visit x }.join ', '}",
+ "SELECT",
+ (visit(o.top) if o.top),
+ "#{o.projections.map { |x| visit x }.join ', '}",
("FROM #{visit o.froms}" if o.froms),
("WHERE #{o.wheres.map { |x| visit x }.join ' AND ' }" unless o.wheres.empty?),
("GROUP BY #{o.groups.map { |x| visit x }.join ', ' }" unless o.groups.empty?),
@@ -100,6 +102,15 @@ module Arel
"OFFSET #{visit o.expr}"
end
+ def visit_Arel_Nodes_Limit o
+ "LIMIT #{visit o.expr}"
+ end
+
+ # FIXME: this does nothing on most databases, but does on MSSQL
+ def visit_Arel_Nodes_Top o
+ ""
+ end
+
# FIXME: this does nothing on SQLLite3, but should do things on other
# databases.
def visit_Arel_Nodes_Lock o
diff --git a/test/visitors/test_mssql.rb b/test/visitors/test_mssql.rb
new file mode 100644
index 0000000000..b658e46828
--- /dev/null
+++ b/test/visitors/test_mssql.rb
@@ -0,0 +1,18 @@
+require 'helper'
+
+module Arel
+ module Visitors
+ describe 'the mssql visitor' do
+ before do
+ @visitor = MSSQL.new Table.engine
+ end
+
+ it 'uses TOP to limit results' do
+ stmt = Nodes::SelectStatement.new
+ stmt.cores.last.top = Nodes::Top.new(1)
+ sql = @visitor.accept(stmt)
+ sql.must_be_like "SELECT TOP 1"
+ end
+ end
+ end
+end
diff --git a/test/visitors/test_to_sql.rb b/test/visitors/test_to_sql.rb
index e08dc89793..33783f7d23 100644
--- a/test/visitors/test_to_sql.rb
+++ b/test/visitors/test_to_sql.rb
@@ -32,7 +32,7 @@ module Arel
it "should escape LIMIT" do
sc = Arel::Nodes::SelectStatement.new
- sc.limit = "omg"
+ sc.limit = Arel::Nodes::Limit.new("omg")
assert_match(/LIMIT 'omg'/, @visitor.accept(sc))
end
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 02:43:37 +0000