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authorShane Emmons <semmons99@gmail.com>2011-04-29 10:10:06 -0400
committerShane Emmons <semmons99@gmail.com>2011-04-29 10:10:06 -0400
commitc2e7f36f87184f23e9d83269ff20f99a29ec75ad (patch)
treefe0cd4b5f8e8acacf2a830a0032467c4878852d8
parent909538048e17cea47f5c57f36ca103865ea17353 (diff)
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replace 'LIMIT n' with 'FETCH FIRST n ROWS ONLY' when using ibm_db
-rw-r--r--lib/arel/visitors.rb2
-rw-r--r--lib/arel/visitors/ibm_db.rb12
-rw-r--r--test/visitors/test_ibm_db.rb27
3 files changed, 41 insertions, 0 deletions
diff --git a/lib/arel/visitors.rb b/lib/arel/visitors.rb
index 8410b2b912..f2644d7205 100644
--- a/lib/arel/visitors.rb
+++ b/lib/arel/visitors.rb
@@ -10,6 +10,7 @@ require 'arel/visitors/join_sql'
require 'arel/visitors/where_sql'
require 'arel/visitors/order_clauses'
require 'arel/visitors/dot'
+require 'arel/visitors/ibm_db'
module Arel
module Visitors
@@ -22,6 +23,7 @@ module Arel
'oracle_enhanced' => Arel::Visitors::Oracle,
'sqlite' => Arel::Visitors::SQLite,
'sqlite3' => Arel::Visitors::SQLite,
+ 'ibm_db' => Arel::Visitors::IBM_DB,
}
ENGINE_VISITORS = Hash.new do |hash, engine|
diff --git a/lib/arel/visitors/ibm_db.rb b/lib/arel/visitors/ibm_db.rb
new file mode 100644
index 0000000000..0c26a3ae9e
--- /dev/null
+++ b/lib/arel/visitors/ibm_db.rb
@@ -0,0 +1,12 @@
+module Arel
+ module Visitors
+ class IBM_DB < Arel::Visitors::ToSql
+ private
+
+ def visit_Arel_Nodes_Limit o
+ "FETCH FIRST #{visit o.expr} ROWS ONLY"
+ end
+
+ end
+ end
+end
diff --git a/test/visitors/test_ibm_db.rb b/test/visitors/test_ibm_db.rb
new file mode 100644
index 0000000000..cc35bb768d
--- /dev/null
+++ b/test/visitors/test_ibm_db.rb
@@ -0,0 +1,27 @@
+require 'helper'
+
+module Arel
+ module Visitors
+ describe 'the ibm_db visitor' do
+ before do
+ @visitor = IBM_DB.new Table.engine
+ end
+
+ it 'uses FETCH FIRST n ROWS to limit results' do
+ stmt = Nodes::SelectStatement.new
+ stmt.limit = Nodes::Limit.new(1)
+ sql = @visitor.accept(stmt)
+ sql.must_be_like "SELECT FETCH FIRST 1 ROWS ONLY"
+ end
+
+ it 'uses FETCH FIRST n ROWS in updates with a limit' do
+ stmt = Nodes::UpdateStatement.new
+ stmt.limit = Nodes::Limit.new(1)
+ stmt.key = 'id'
+ sql = @visitor.accept(stmt)
+ sql.must_be_like "UPDATE NULL WHERE 'id' IN (SELECT 'id' FETCH FIRST 1 ROWS ONLY)"
+ end
+
+ end
+ end
+end