Disallow usage of paged_delete in paged_operations plugin on MSSQL wi…

…th emulated offsets

lib/sequel/plugins/paged_operations.rb

@@ -119,8 +119,8 @@ def paged_datasets(opts=OPTS)
  # :rows_per_page :: The maximum number of rows affected by each DELETE query
  # (unless concurrent modifications are made to the table).
  def paged_delete(opts=OPTS)
- if db.database_type == :oracle && !supports_fetch_next_rows?
- raise Error, "paged_delete is not supported on Oracle when using emulated offsets"
+ if (db.database_type == :oracle && !supports_fetch_next_rows?) || (db.database_type == :mssql && !is_2012_or_later?)
+ raise Error, "paged_delete is not supported on MSSQL/Oracle when using emulated offsets"
  end
  pk = _paged_operations_pk(:paged_delete)
  rows_deleted = 0

spec/extensions/paged_operations_spec.rb

@@ -181,6 +181,14 @@
  proc{@ds.limit(1).paged_datasets{}}.must_raise Sequel::Error
  end
 
+ it "should raise error paged_delete for MSSQL with emulated offsets" do
+ db = Sequel.connect('mock://mssql')
+ def db.server_version(_=nil); 10000000; end
+ @c.dataset = db[:t]
+ ds = @c.dataset
+ proc{ds.paged_delete}.must_raise Sequel::Error
+ end
+
  it "should raise error for DB2 with emulated offsets" do
  @c.dataset = Sequel.connect('mock://db2')[:t]
  ds = @c.dataset

spec/integration/plugin_test.rb

@@ -3048,7 +3048,7 @@ def set(k, v, ttl) self[k] = v end
  end
  @model.paged_delete.must_equal 100
  @model.count.must_equal 0
- end unless (DB.database_type == :oracle && !DB.dataset.supports_fetch_next_rows?)
+ end unless (DB.database_type == :oracle && !DB.dataset.supports_fetch_next_rows?) || (DB.database_type == :mssql && !DB.dataset.send(:is_2012_or_later?))
 
  it "Model#paged_update should work on unfiltered dataset" do
  expected = 100.times.map{|i| [i+1, i+200]}
@@ -3089,7 +3089,7 @@ def set(k, v, ttl) self[k] = v end
  ds.paged_delete.must_equal 49
  ds.count.must_equal 0
  @model.count.must_equal 51
- end unless (DB.database_type == :oracle && !DB.dataset.supports_fetch_next_rows?)
+ end unless (DB.database_type == :oracle && !DB.dataset.supports_fetch_next_rows?) || (DB.database_type == :mssql && !DB.dataset.send(:is_2012_or_later?))
 
  it "Model#paged_update should work on filtered dataset" do
  ds = @model.where{id < 50}