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}