diff --git a/lib/active_record/connection_adapters/sqlserver/core_ext/attribute_methods.rb b/lib/active_record/connection_adapters/sqlserver/core_ext/attribute_methods.rb
index af0e6a4e7..639874a81 100644
--- a/lib/active_record/connection_adapters/sqlserver/core_ext/attribute_methods.rb
+++ b/lib/active_record/connection_adapters/sqlserver/core_ext/attribute_methods.rb
@@ -10,11 +10,13 @@ module AttributeMethods
           private
 
           def attributes_for_update(attribute_names)
-            return super unless self.class.connection.adapter_name == "SQLServer"
+            self.class.with_connection do |connection|
+              return super(attribute_names) unless connection.sqlserver?
 
-            super.reject do |name|
-              column = self.class.columns_hash[name]
-              column && column.respond_to?(:is_identity?) && column.is_identity?
+              super(attribute_names).reject do |name|
+                column = self.class.columns_hash[name]
+                column && column.respond_to?(:is_identity?) && column.is_identity?
+              end
             end
           end
         end
diff --git a/lib/active_record/connection_adapters/sqlserver/core_ext/calculations.rb b/lib/active_record/connection_adapters/sqlserver/core_ext/calculations.rb
index 34355ef53..54af006b7 100644
--- a/lib/active_record/connection_adapters/sqlserver/core_ext/calculations.rb
+++ b/lib/active_record/connection_adapters/sqlserver/core_ext/calculations.rb
@@ -9,10 +9,12 @@ module SQLServer
       module CoreExt
         module Calculations
           def calculate(operation, column_name)
-            if klass.connection.sqlserver?
-              _calculate(operation, column_name)
-            else
-              super
+            klass.with_connection do |connection|
+              if connection.sqlserver?
+                _calculate(operation, column_name)
+              else
+                super
+              end
             end
           end
 
@@ -54,9 +56,10 @@ def _calculate(operation, column_name)
           end
 
           def build_count_subquery(relation, column_name, distinct)
-            return super unless klass.connection.adapter_name == "SQLServer"
-
-            super(relation.unscope(:order), column_name, distinct)
+            klass.with_connection do |connection|
+              relation = relation.unscope(:order) if connection.sqlserver?
+              super(relation, column_name, distinct)
+            end
           end
         end
       end
diff --git a/lib/active_record/connection_adapters/sqlserver/core_ext/explain.rb b/lib/active_record/connection_adapters/sqlserver/core_ext/explain.rb
index 4eea43e3d..d9ca051cf 100644
--- a/lib/active_record/connection_adapters/sqlserver/core_ext/explain.rb
+++ b/lib/active_record/connection_adapters/sqlserver/core_ext/explain.rb
@@ -9,12 +9,14 @@ module Explain
           SQLSERVER_STATEMENT_REGEXP = /N'(.+)', N'(.+)', (.+)/
 
           def exec_explain(queries, options = [])
-            return super unless connection.adapter_name == "SQLServer"
+            with_connection do |connection|
+              return super(queries, options) unless connection.sqlserver?
 
-            unprepared_queries = queries.map do |(sql, binds)|
-              [unprepare_sqlserver_statement(sql, binds), binds]
+              unprepared_queries = queries.map do |(sql, binds)|
+                [unprepare_sqlserver_statement(sql, binds), binds]
+              end
+              super(unprepared_queries, options)
             end
-            super(unprepared_queries, options)
           end
 
           private
diff --git a/lib/active_record/connection_adapters/sqlserver/core_ext/finder_methods.rb b/lib/active_record/connection_adapters/sqlserver/core_ext/finder_methods.rb
index fe9271508..6016369c2 100644
--- a/lib/active_record/connection_adapters/sqlserver/core_ext/finder_methods.rb
+++ b/lib/active_record/connection_adapters/sqlserver/core_ext/finder_methods.rb
@@ -11,10 +11,12 @@ module FinderMethods
           private
 
           def construct_relation_for_exists(conditions)
-            if klass.connection.sqlserver?
-              _construct_relation_for_exists(conditions)
-            else
-              super
+            klass.with_connection do |connection|
+              if connection.sqlserver?
+                _construct_relation_for_exists(conditions)
+              else
+                super
+              end
             end
           end
 
diff --git a/lib/active_record/connection_adapters/sqlserver/core_ext/preloader.rb b/lib/active_record/connection_adapters/sqlserver/core_ext/preloader.rb
index 046edb3ea..d7bc7b9e4 100644
--- a/lib/active_record/connection_adapters/sqlserver/core_ext/preloader.rb
+++ b/lib/active_record/connection_adapters/sqlserver/core_ext/preloader.rb
@@ -8,23 +8,25 @@ module SQLServer
       module CoreExt
         module LoaderQuery
           def load_records_for_keys(keys, &block)
-            return super unless scope.connection.sqlserver?
+            scope.with_connection do |connection|
+              return super unless connection.sqlserver?
 
-            return [] if keys.empty?
+              return [] if keys.empty?
 
-            if association_key_name.is_a?(Array)
-              query_constraints = Hash.new { |hsh, key| hsh[key] = Set.new }
+              if association_key_name.is_a?(Array)
+                query_constraints = Hash.new { |hsh, key| hsh[key] = Set.new }
 
-              keys.each_with_object(query_constraints) do |values_set, constraints|
-                association_key_name.zip(values_set).each do |key_name, value|
-                  constraints[key_name] << value
+                keys.each_with_object(query_constraints) do |values_set, constraints|
+                  association_key_name.zip(values_set).each do |key_name, value|
+                    constraints[key_name] << value
+                  end
                 end
-              end
 
-              scope.where(query_constraints).load(&block)
-            else
-              keys.each_slice(in_clause_length).flat_map do |slice|
-                scope.where(association_key_name => slice).load(&block).records
+                scope.where(query_constraints).load(&block)
+              else
+                keys.each_slice(in_clause_length).flat_map do |slice|
+                  scope.where(association_key_name => slice).load(&block).records
+                end
               end
             end
           end
diff --git a/lib/active_record/connection_adapters/sqlserver_adapter.rb b/lib/active_record/connection_adapters/sqlserver_adapter.rb
index 1e272d913..bffaad63a 100644
--- a/lib/active_record/connection_adapters/sqlserver_adapter.rb
+++ b/lib/active_record/connection_adapters/sqlserver_adapter.rb
@@ -29,12 +29,13 @@
 require "active_record/connection_adapters/sqlserver/table_definition"
 require "active_record/connection_adapters/sqlserver/quoting"
 require "active_record/connection_adapters/sqlserver/utils"
-require "active_record/sqlserver_base"
 require "active_record/connection_adapters/sqlserver_column"
 require "active_record/tasks/sqlserver_database_tasks"
 
 module ActiveRecord
   module ConnectionAdapters
+    register "sqlserver", "ActiveRecord::ConnectionAdapters::SQLServerAdapter", "active_record/connection_adapters/sqlserver_adapter"
+
     class SQLServerAdapter < AbstractAdapter
       include SQLServer::Version,
               SQLServer::Quoting,
diff --git a/lib/active_record/sqlserver_base.rb b/lib/active_record/sqlserver_base.rb
deleted file mode 100644
index 9dbcbc623..000000000
--- a/lib/active_record/sqlserver_base.rb
+++ /dev/null
@@ -1,13 +0,0 @@
-# frozen_string_literal: true
-
-module ActiveRecord
-  module ConnectionHandling
-    def sqlserver_adapter_class
-      ConnectionAdapters::SQLServerAdapter
-    end
-
-    def sqlserver_connection(config) #:nodoc:
-      sqlserver_adapter_class.new(config)
-    end
-  end
-end
diff --git a/test/cases/adapter_test_sqlserver.rb b/test/cases/adapter_test_sqlserver.rb
index 34394732b..5c392513b 100644
--- a/test/cases/adapter_test_sqlserver.rb
+++ b/test/cases/adapter_test_sqlserver.rb
@@ -61,8 +61,8 @@ class AdapterTestSQLServer < ActiveRecord::TestCase
   end
 
   it "test table existence across database schemas" do
-    arunit_connection = Topic.connection
-    arunit2_connection = College.connection
+    arunit_connection = Topic.lease_connection
+    arunit2_connection = College.lease_connection
 
     arunit_database = arunit_connection.pool.db_config.database
     arunit2_database = arunit2_connection.pool.db_config.database
@@ -508,7 +508,7 @@ class AdapterTestSQLServer < ActiveRecord::TestCase
 
   describe "block writes to a database" do
     def setup
-      @conn = ActiveRecord::Base.connection
+      @conn = ActiveRecord::Base.lease_connection
     end
 
     def test_errors_when_an_insert_query_is_called_while_preventing_writes
diff --git a/test/cases/coerced_tests.rb b/test/cases/coerced_tests.rb
index 315a2ac45..d2070c97a 100644
--- a/test/cases/coerced_tests.rb
+++ b/test/cases/coerced_tests.rb
@@ -56,7 +56,7 @@ def test_partial_index_coerced
 
     t = Topic.create!(title: "abc")
     t.author_name = "John"
-    assert_queries(1) do
+    assert_queries_count(1) do
       t.valid?
     end
   end
@@ -197,7 +197,7 @@ class BasicsTest < ActiveRecord::TestCase
   # Use square brackets as SQL Server escaped character
   coerce_tests! :test_column_names_are_escaped
   def test_column_names_are_escaped_coerced
-    conn = ActiveRecord::Base.connection
+    conn = ActiveRecord::Base.lease_connection
     assert_equal "[t]]]", conn.quote_column_name("t]")
   end
 
@@ -234,9 +234,9 @@ def test_update_date_time_attributes_with_default_timezone_local
   coerce_tests! %r{an empty transaction does not raise if preventing writes}
   test "an empty transaction does not raise if preventing writes coerced" do
     ActiveRecord::Base.while_preventing_writes do
-      assert_queries(1, ignore_none: true) do
+      assert_queries_count(1, ignore_none: true) do
         Bird.transaction do
-          ActiveRecord::Base.connection.materialize_transactions
+          ActiveRecord::Base.lease_connection.materialize_transactions
         end
       end
     end
@@ -490,8 +490,8 @@ def test_limit_with_offset_is_kept_coerced
   coerce_tests! :test_distinct_count_all_with_custom_select_and_order
   def test_distinct_count_all_with_custom_select_and_order_coerced
     accounts = Account.distinct.select("credit_limit % 10 AS the_limit").order(Arel.sql("credit_limit % 10"))
-    assert_queries(1) { assert_equal 3, accounts.count(:all) }
-    assert_queries(1) { assert_equal 3, accounts.load.size }
+    assert_queries_count(1) { assert_equal 3, accounts.count(:all) }
+    assert_queries_count(1) { assert_equal 3, accounts.load.size }
   end
 
   # Leave it up to users to format selects/functions so HAVING works correctly.
@@ -1018,7 +1018,7 @@ def test_implicit_order_column_is_configurable_coerced
     assert_equal topics(:fifth), Topic.first
     assert_equal topics(:third), Topic.last
 
-    c = Topic.connection
+    c = Topic.lease_connection
     assert_sql(/ORDER BY #{Regexp.escape(c.quote_table_name("topics.title"))} DESC, #{Regexp.escape(c.quote_table_name("topics.id"))} DESC OFFSET 0 ROWS FETCH NEXT @0 ROWS ONLY.*@0 = 1/i) {
       Topic.last
     }
@@ -1032,7 +1032,7 @@ def test_implicit_order_set_to_primary_key_coerced
     old_implicit_order_column = Topic.implicit_order_column
     Topic.implicit_order_column = "id"
 
-    c = Topic.connection
+    c = Topic.lease_connection
     assert_sql(/ORDER BY #{Regexp.escape(c.quote_table_name("topics.id"))} DESC OFFSET 0 ROWS FETCH NEXT @0 ROWS ONLY.*@0 = 1/i) {
       Topic.last
     }
@@ -1046,7 +1046,7 @@ def test_implicit_order_for_model_without_primary_key_coerced
     old_implicit_order_column = NonPrimaryKey.implicit_order_column
     NonPrimaryKey.implicit_order_column = "created_at"
 
-    c = NonPrimaryKey.connection
+    c = NonPrimaryKey.lease_connection
 
     assert_sql(/ORDER BY #{Regexp.escape(c.quote_table_name("non_primary_keys.created_at"))} DESC OFFSET 0 ROWS FETCH NEXT @0 ROWS ONLY.*@0 = 1/i) {
       NonPrimaryKey.last
@@ -1067,7 +1067,7 @@ def test_member_on_unloaded_relation_with_composite_primary_key_coerced
   # Check for `FETCH NEXT x ROWS` rather then `LIMIT`.
   coerce_tests! :test_implicit_order_column_prepends_query_constraints
   def test_implicit_order_column_prepends_query_constraints_coerced
-    c = ClothingItem.connection
+    c = ClothingItem.lease_connection
     ClothingItem.implicit_order_column = "description"
     quoted_type = Regexp.escape(c.quote_table_name("clothing_items.clothing_type"))
     quoted_color = Regexp.escape(c.quote_table_name("clothing_items.color"))
@@ -1083,7 +1083,7 @@ def test_implicit_order_column_prepends_query_constraints_coerced
   # Check for `FETCH NEXT x ROWS` rather then `LIMIT`.
   coerce_tests! %r{#last for a model with composite query constraints}
   test "#last for a model with composite query constraints coerced" do
-    c = ClothingItem.connection
+    c = ClothingItem.lease_connection
     quoted_type = Regexp.escape(c.quote_table_name("clothing_items.clothing_type"))
     quoted_color = Regexp.escape(c.quote_table_name("clothing_items.color"))
 
@@ -1095,7 +1095,7 @@ def test_implicit_order_column_prepends_query_constraints_coerced
   # Check for `FETCH NEXT x ROWS` rather then `LIMIT`.
   coerce_tests! %r{#first for a model with composite query constraints}
   test "#first for a model with composite query constraints coerced" do
-    c = ClothingItem.connection
+    c = ClothingItem.lease_connection
     quoted_type = Regexp.escape(c.quote_table_name("clothing_items.clothing_type"))
     quoted_color = Regexp.escape(c.quote_table_name("clothing_items.color"))
 
@@ -1107,7 +1107,7 @@ def test_implicit_order_column_prepends_query_constraints_coerced
   # Check for `FETCH NEXT x ROWS` rather then `LIMIT`.
   coerce_tests! :test_implicit_order_column_reorders_query_constraints
   def test_implicit_order_column_reorders_query_constraints_coerced
-    c = ClothingItem.connection
+    c = ClothingItem.lease_connection
     ClothingItem.implicit_order_column = "color"
     quoted_type = Regexp.escape(c.quote_table_name("clothing_items.clothing_type"))
     quoted_color = Regexp.escape(c.quote_table_name("clothing_items.color"))
@@ -1131,7 +1131,7 @@ def test_include_on_unloaded_relation_with_composite_primary_key_coerced
   # Check for `FETCH NEXT x ROWS` rather then `LIMIT`.
   coerce_tests! :test_nth_to_last_with_order_uses_limit
   def test_nth_to_last_with_order_uses_limit_coerced
-    c = Topic.connection
+    c = Topic.lease_connection
     assert_sql(/ORDER BY #{Regexp.escape(c.quote_table_name("topics.id"))} DESC OFFSET @(\d) ROWS FETCH NEXT @(\d) ROWS ONLY.*@\1 = 1.*@\2 = 1/i) do
       Topic.second_to_last
     end
@@ -1324,7 +1324,7 @@ def test_create_without_primary_key_no_extra_query_coerced
       self.table_name = "dashboards"
     end
     klass.create! # warmup schema cache
-    assert_queries(2, ignore_none: true) { klass.create! }
+    assert_queries_count(2, ignore_none: true) { klass.create! }
   end
 end
 
@@ -1354,7 +1354,7 @@ def test_query_cached_even_when_types_are_reset_coerced
       Task.initialize_find_by_cache
       Task.define_attribute_methods
 
-      assert_queries(1, ignore_none: true) do
+      assert_queries_count(1, ignore_none: true) do
         Task.find(1)
       end
 
@@ -1454,11 +1454,11 @@ def test_relations_dont_load_all_records_in_pretty_print_coerced
   def test_empty_complex_chained_relations_coerced
     posts = Post.select("comments_count").where("id is not null").group("author_id", "id").where("legacy_comments_count > 0")
 
-    assert_queries(1) { assert_equal false, posts.empty? }
+    assert_queries_count(1) { assert_equal false, posts.empty? }
     assert_not_predicate posts, :loaded?
 
     no_posts = posts.where(title: "")
-    assert_queries(1) { assert_equal true, no_posts.empty? }
+    assert_queries_count(1) { assert_equal true, no_posts.empty? }
     assert_not_predicate no_posts, :loaded?
   end
 
@@ -1542,9 +1542,9 @@ def test_dump_schema_information_outputs_lexically_reverse_ordered_versions_rega
       @schema_migration.create_version(v)
     end
 
-    schema_info = ActiveRecord::Base.connection.dump_schema_information
+    schema_info = ActiveRecord::Base.lease_connection.dump_schema_information
     expected = <<~STR
-    INSERT INTO #{ActiveRecord::Base.connection.quote_table_name("schema_migrations")} (version) VALUES
+    INSERT INTO #{ActiveRecord::Base.lease_connection.quote_table_name("schema_migrations")} (version) VALUES
     (N'20100301010101'),
     (N'20100201010101'),
     (N'20100101010101');
@@ -1602,7 +1602,7 @@ class SchemaDumperDefaultsCoerceTest < ActiveRecord::TestCase
   include SchemaDumpingHelper
 
   setup do
-    @connection = ActiveRecord::Base.connection
+    @connection = ActiveRecord::Base.lease_connection
     @connection.create_table :dump_defaults, force: true do |t|
       t.string   :string_with_default,   default: "Hello!"
       t.date     :date_with_default,     default: "2014-06-05"
@@ -2213,15 +2213,15 @@ def test_insert_all_coerced
       Task.cache { Task.insert({ starting: Time.now }) }
     end
 
-    assert_called(ActiveRecord::Base.connection, :clear_query_cache, times: 2) do
+    assert_called(ActiveRecord::Base.lease_connection, :clear_query_cache, times: 2) do
       Task.cache { Task.insert_all!([{ starting: Time.now }]) }
     end
 
-    assert_called(ActiveRecord::Base.connection, :clear_query_cache, times: 2) do
+    assert_called(ActiveRecord::Base.lease_connection, :clear_query_cache, times: 2) do
       Task.cache { Task.insert!({ starting: Time.now }) }
     end
 
-    assert_called(ActiveRecord::Base.connection, :clear_query_cache, times: 2) do
+    assert_called(ActiveRecord::Base.lease_connection, :clear_query_cache, times: 2) do
       Task.cache { Task.insert_all!([{ starting: Time.now }]) }
     end
 
@@ -2287,7 +2287,7 @@ class MarshalSerializationTest < ActiveRecord::TestCase
   undef_method :marshal_fixture_path
   def marshal_fixture_path(file_name)
     File.expand_path(
-      "support/marshal_compatibility_fixtures/#{ActiveRecord::Base.connection.adapter_name}/#{file_name}.dump",
+      "support/marshal_compatibility_fixtures/#{ActiveRecord::Base.lease_connection.adapter_name}/#{file_name}.dump",
       ARTest::SQLServer.test_root_sqlserver
     )
   end
@@ -2338,7 +2338,7 @@ def test_preloads_has_many_on_model_with_a_composite_primary_key_through_id_attr
     assert_equal 2, sql.size
     preload_sql = sql.last
 
-    c = Cpk::OrderAgreement.connection
+    c = Cpk::OrderAgreement.lease_connection
     order_id_column = Regexp.escape(c.quote_table_name("cpk_order_agreements.order_id"))
     order_id_constraint = /#{order_id_column} = @0.*@0 = \d+$/
     expectation = /SELECT.*WHERE.* #{order_id_constraint}/
@@ -2362,7 +2362,7 @@ def test_preloads_belongs_to_a_composite_primary_key_model_through_id_attribute_
     assert_equal 2, sql.size
     preload_sql = sql.last
 
-    c = Cpk::Order.connection
+    c = Cpk::Order.lease_connection
     order_id = Regexp.escape(c.quote_table_name("cpk_orders.id"))
     order_constraint = /#{order_id} = @0.*@0 = \d+$/
     expectation = /SELECT.*WHERE.* #{order_constraint}/
@@ -2377,9 +2377,9 @@ class BasePreventWritesTest < ActiveRecord::TestCase
   coerce_tests! %r{an empty transaction does not raise if preventing writes}
   test "an empty transaction does not raise if preventing writes coerced" do
     ActiveRecord::Base.while_preventing_writes do
-      assert_queries(1, ignore_none: true) do
+      assert_queries_count(1, ignore_none: true) do
         Bird.transaction do
-          ActiveRecord::Base.connection.materialize_transactions
+          ActiveRecord::Base.lease_connection.materialize_transactions
         end
       end
     end
@@ -2489,7 +2489,7 @@ def test_sqlcommenter_format_value_string_coercible_coerced
   def test_invalid_encoding_query_coerced
     ActiveRecord::QueryLogs.tags = [ :application ]
     assert_raises ActiveRecord::StatementInvalid do
-      ActiveRecord::Base.connection.execute "select 1 as '\xFF'"
+      ActiveRecord::Base.lease_connection.execute "select 1 as '\xFF'"
     end
   end
 end
diff --git a/test/cases/disconnected_test_sqlserver.rb b/test/cases/disconnected_test_sqlserver.rb
index 2936cf93f..382ca51b2 100644
--- a/test/cases/disconnected_test_sqlserver.rb
+++ b/test/cases/disconnected_test_sqlserver.rb
@@ -7,7 +7,7 @@ class TestDisconnectedAdapter < ActiveRecord::TestCase
 
   undef_method :setup
   def setup
-    @connection = ActiveRecord::Base.connection
+    @connection = ActiveRecord::Base.lease_connection
   end
 
   teardown do
diff --git a/test/cases/eager_load_too_many_ids_test_sqlserver.rb b/test/cases/eager_load_too_many_ids_test_sqlserver.rb
index 96eaa6cf9..72ba24625 100644
--- a/test/cases/eager_load_too_many_ids_test_sqlserver.rb
+++ b/test/cases/eager_load_too_many_ids_test_sqlserver.rb
@@ -11,7 +11,7 @@ def test_batch_preloading_too_many_ids
     # We Monkey patch Preloader to work with batches of 10_000 records.
     # Expect: N Books queries + Citation query
     expected_query_count = (Citation.count / in_clause_length.to_f).ceil + 1
-    assert_queries(expected_query_count) do
+    assert_queries_count(expected_query_count) do
       Citation.preload(:reference_of).to_a.size
     end
   end
diff --git a/test/cases/json_test_sqlserver.rb b/test/cases/json_test_sqlserver.rb
index a863868a8..501210a12 100644
--- a/test/cases/json_test_sqlserver.rb
+++ b/test/cases/json_test_sqlserver.rb
@@ -2,7 +2,7 @@
 
 require "cases/helper_sqlserver"
 
-if ActiveRecord::Base.connection.supports_json?
+if ActiveRecord::Base.lease_connection.supports_json?
   class JsonTestSQLServer < ActiveRecord::TestCase
     before do
       @o1 = SSTestDatatypeMigrationJson.create! json_col: { "a" => "a", "b" => "b", "c" => "c" }
diff --git a/test/cases/lateral_test_sqlserver.rb b/test/cases/lateral_test_sqlserver.rb
index 17aea3c9b..fb1660110 100644
--- a/test/cases/lateral_test_sqlserver.rb
+++ b/test/cases/lateral_test_sqlserver.rb
@@ -16,7 +16,7 @@ class LateralTestSQLServer < ActiveRecord::TestCase
     eq = Arel::Nodes::Equality.new(one, one)
 
     sql = author.project(Arel.star).where(author[:name].matches("David")).outer_join(subselect.lateral.as("bar")).on(eq).to_sql
-    results = ActiveRecord::Base.connection.exec_query sql
+    results = ActiveRecord::Base.lease_connection.exec_query sql
     assert_equal sql, "SELECT * FROM [authors] OUTER APPLY (SELECT * FROM [posts] WHERE [posts].[author_id] = [authors].[id] AND [posts].[id] = 42 ORDER BY [posts].[id] ASC OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY) AS bar WHERE [authors].[name] LIKE N'David'"
     assert_equal results.length, 1
   end
@@ -27,7 +27,7 @@ class LateralTestSQLServer < ActiveRecord::TestCase
     subselect = post.project(Arel.star).take(1).where(post[:author_id].eq(author[:id])).where(post[:id].eq(42))
 
     sql = author.project(Arel.star).where(author[:name].matches("David")).join(subselect.lateral.as("bar")).to_sql
-    results = ActiveRecord::Base.connection.exec_query sql
+    results = ActiveRecord::Base.lease_connection.exec_query sql
 
     assert_equal sql, "SELECT * FROM [authors] CROSS APPLY (SELECT * FROM [posts] WHERE [posts].[author_id] = [authors].[id] AND [posts].[id] = 42 ORDER BY [posts].[id] ASC OFFSET 0 ROWS FETCH NEXT 1 ROWS ONLY) AS bar WHERE [authors].[name] LIKE N'David'"
     assert_equal results.length, 0
diff --git a/test/cases/primary_keys_test_sqlserver.rb b/test/cases/primary_keys_test_sqlserver.rb
index 433c17de0..8edf3dcfe 100644
--- a/test/cases/primary_keys_test_sqlserver.rb
+++ b/test/cases/primary_keys_test_sqlserver.rb
@@ -12,7 +12,7 @@ class Barcode < ActiveRecord::Base
   end
 
   setup do
-    @connection = ActiveRecord::Base.connection
+    @connection = ActiveRecord::Base.lease_connection
     @connection.create_table(:barcodes, primary_key: "code", id: :uuid, force: true)
   end
 
@@ -50,7 +50,7 @@ class Widget < ActiveRecord::Base
   end
 
   setup do
-    @connection = ActiveRecord::Base.connection
+    @connection = ActiveRecord::Base.lease_connection
   end
 
   teardown do
diff --git a/test/cases/schema_dumper_test_sqlserver.rb b/test/cases/schema_dumper_test_sqlserver.rb
index 13ba5b5ce..f6ae6b2c3 100644
--- a/test/cases/schema_dumper_test_sqlserver.rb
+++ b/test/cases/schema_dumper_test_sqlserver.rb
@@ -5,7 +5,7 @@
 class SchemaDumperTestSQLServer < ActiveRecord::TestCase
   before { all_tables }
 
-  let(:all_tables)   { ActiveRecord::Base.connection.tables }
+  let(:all_tables)   { ActiveRecord::Base.lease_connection.tables }
   let(:schema)       { @generated_schema }
 
   it "sst_datatypes" do
@@ -166,7 +166,7 @@ def generate_schema_for_table(*table_names)
 
     stream = StringIO.new
     ActiveRecord::SchemaDumper.ignore_tables = all_tables - table_names
-    ActiveRecord::SchemaDumper.dump(ActiveRecord::Base.connection, stream)
+    ActiveRecord::SchemaDumper.dump(ActiveRecord::Base.lease_connection, stream)
     @generated_schema = stream.string
     yield @generated_schema if block_given?
     @schema_lines = Hash.new
diff --git a/test/cases/specific_schema_test_sqlserver.rb b/test/cases/specific_schema_test_sqlserver.rb
index 6148f0874..c4590ce81 100644
--- a/test/cases/specific_schema_test_sqlserver.rb
+++ b/test/cases/specific_schema_test_sqlserver.rb
@@ -159,14 +159,14 @@ def quoted_id
 
   it "returns a new id via connection newid_function" do
     acceptable_uuid = ActiveRecord::ConnectionAdapters::SQLServer::Type::Uuid::ACCEPTABLE_UUID
-    db_uuid = ActiveRecord::Base.connection.newid_function
+    db_uuid = ActiveRecord::Base.lease_connection.newid_function
     _(db_uuid).must_match(acceptable_uuid)
   end
 
   # with similar table definition in two schemas
 
   it "returns the correct primary columns" do
-    connection = ActiveRecord::Base.connection
+    connection = ActiveRecord::Base.lease_connection
     assert_equal "field_1", connection.columns("test.sst_schema_test_mulitple_schema").detect(&:is_primary?).name
     assert_equal "field_2", connection.columns("test2.sst_schema_test_mulitple_schema").detect(&:is_primary?).name
   end
diff --git a/test/cases/view_test_sqlserver.rb b/test/cases/view_test_sqlserver.rb
index b371bd0b1..73ddf006a 100644
--- a/test/cases/view_test_sqlserver.rb
+++ b/test/cases/view_test_sqlserver.rb
@@ -3,7 +3,7 @@
 require "cases/helper_sqlserver"
 
 class ViewTestSQLServer < ActiveRecord::TestCase
-  let(:connection) { ActiveRecord::Base.connection }
+  let(:connection) { ActiveRecord::Base.lease_connection }
 
   describe 'view with default values' do
     before do
diff --git a/test/support/connection_reflection.rb b/test/support/connection_reflection.rb
index a739f76ee..b7fe15ce2 100644
--- a/test/support/connection_reflection.rb
+++ b/test/support/connection_reflection.rb
@@ -8,7 +8,7 @@ module ConnectionReflection
       included { extend ConnectionReflection }
 
       def connection
-        ActiveRecord::Base.connection
+        ActiveRecord::Base.lease_connection
       end
 
       def connection_options
diff --git a/test/support/test_in_memory_oltp.rb b/test/support/test_in_memory_oltp.rb
index 88c918c92..2b5bb0c19 100644
--- a/test/support/test_in_memory_oltp.rb
+++ b/test/support/test_in_memory_oltp.rb
@@ -8,10 +8,10 @@
 
   ARTest.connect
 
-  if ActiveRecord::Base.connection.supports_in_memory_oltp?
+  if ActiveRecord::Base.lease_connection.supports_in_memory_oltp?
     puts "Configuring In-Memory OLTP..."
     inmem_file = ARTest::SQLServer.test_root_sqlserver, "schema", "enable-in-memory-oltp.sql"
     inmem_sql = File.read File.join(inmem_file)
-    ActiveRecord::Base.connection.execute(inmem_sql)
+    ActiveRecord::Base.lease_connection.execute(inmem_sql)
   end
 end