adapter_test_sqlserver.rb

# frozen_string_literal: true

require "cases/helper_sqlserver"
require "models/topic"
require "models/task"
require "models/post"
require "models/subscriber"
require "models/minimalistic"
require "models/college"
require "models/discount"

class AdapterTestSQLServer < ActiveRecord::TestCase
  fixtures :tasks

  let(:basic_insert_sql) { "INSERT INTO [funny_jokes] ([name]) VALUES('Knock knock')" }
  let(:basic_merge_sql) { "MERGE INTO [ships] WITH (UPDLOCK, HOLDLOCK) AS target USING ( SELECT * FROM ( SELECT [id], [name], ROW_NUMBER() OVER ( PARTITION BY [id] ORDER BY [id] DESC ) AS rn_0 FROM ( VALUES (101, N'RSS Sir David Attenborough') ) AS t1 ([id], [name]) ) AS ranked_source WHERE rn_0 = 1 ) AS source ON (target.[id] = source.[id]) WHEN MATCHED THEN UPDATE SET target.[name] = source.[name]" }
  let(:basic_update_sql) { "UPDATE [customers] SET [address_street] = NULL WHERE [id] = 2" }
  let(:basic_select_sql) { "SELECT * FROM [customers] WHERE ([customers].[id] = 1)" }

  it "has basic and non-sensitive information in the adapters inspect method" do
    string = connection.inspect
    _(string).must_match %r{ActiveRecord::ConnectionAdapters::SQLServerAdapter}
    _(string).wont_match %r{host}
    _(string).wont_match %r{password}
    _(string).wont_match %r{username}
    _(string).wont_match %r{port}
  end

  it "has a 128 max #table_alias_length" do
    assert connection.table_alias_length <= 128
  end

  it "raises invalid statement error for bad SQL" do
    assert_raise(ActiveRecord::StatementInvalid) { Topic.lease_connection.update("UPDATE XXX") }
  end

  it "is has our adapter_name" do
    assert_equal "SQLServer", connection.adapter_name
  end

  it "support DDL in transactions" do
    assert connection.supports_ddl_transactions?
  end

  it "table exists works if table name prefixed by schema and owner" do
    assert_equal "topics", Topic.table_name
    assert Topic.table_exists?

    # Test when owner included in table name.
    Topic.table_name = "dbo.topics"
    assert Topic.table_exists?, "Topics table name of 'dbo.topics' should return true for exists."

    # Test when database and owner included in table name.
    db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary")
    Topic.table_name = "#{db_config.database}.dbo.topics"
    assert Topic.table_exists?, "Topics table name of '[DATABASE].dbo.topics' should return true for exists."
  ensure
    Topic.table_name = "topics"
  end

  it "test table existence across database schemas" do
    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

    # Assert that connections use different default databases schemas.
    assert_not_equal arunit_database, arunit2_database

    # Assert that the Topics table exists when using the Topics connection.
    assert arunit_connection.table_exists?("topics"), "Topics table exists using table name"
    assert arunit_connection.table_exists?("dbo.topics"), "Topics table exists using owner and table name"
    assert arunit_connection.table_exists?("#{arunit_database}.dbo.topics"), "Topics table exists using database, owner and table name"

    # Assert that the Colleges table exists when using the Colleges connection.
    assert arunit2_connection.table_exists?("colleges"), "College table exists using table name"
    assert arunit2_connection.table_exists?("dbo.colleges"), "College table exists using owner and table name"
    assert arunit2_connection.table_exists?("#{arunit2_database}.dbo.colleges"), "College table exists using database, owner and table name"

    # Assert that the tables exist when using each others connection.
    assert arunit_connection.table_exists?("#{arunit2_database}.dbo.colleges"), "Colleges table exists using Topics connection"
    assert arunit2_connection.table_exists?("#{arunit_database}.dbo.topics"), "Topics table exists using Colleges connection"
  end

  it "return true to insert sql query for inserts only" do
    assert connection.send(:insert_sql?, "INSERT...")
    assert connection.send(:insert_sql?, "EXEC sp_executesql N'INSERT INTO [fk_test_has_fks] ([fk_id]) VALUES (@0); SELECT CAST(SCOPE_IDENTITY() AS bigint) AS Ident', N'@0 int', @0 = 0")
    assert !connection.send(:insert_sql?, "UPDATE...")
    assert !connection.send(:insert_sql?, "SELECT...")
  end

  it "return unquoted table name object from basic INSERT UPDATE and SELECT statements" do
    assert_equal "funny_jokes", connection.send(:get_table_name, basic_insert_sql)
    assert_equal "ships", connection.send(:get_table_name, basic_merge_sql)
    assert_equal "customers", connection.send(:get_table_name, basic_update_sql)
    assert_equal "customers", connection.send(:get_table_name, basic_select_sql)
  end

  it "test bad connection" do
    assert_raise ActiveRecord::NoDatabaseError do
      db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary")
      configuration = db_config.configuration_hash.merge(database: "nonexistent_activerecord_unittest")
      connection = ActiveRecord::ConnectionAdapters::SQLServerAdapter.new(configuration)
      connection.exec_query("SELECT 1")
    end
  end

  it "test database exists returns false if database does not exist" do
    db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary")
    configuration = db_config.configuration_hash.merge(database: "nonexistent_activerecord_unittest")
    assert_not ActiveRecord::ConnectionAdapters::SQLServerAdapter.database_exists?(configuration),
      "expected database #{configuration[:database]} to not exist"
  end

  it "test database exists returns true when the database exists" do
    db_config = ActiveRecord::Base.configurations.configs_for(env_name: "arunit", name: "primary")
    assert ActiveRecord::ConnectionAdapters::SQLServerAdapter.database_exists?(db_config.configuration_hash),
      "expected database #{db_config.database} to exist"
  end

  it "test primary key violation" do
    Post.create!(id: 0, title: "Setup", body: "Create post with primary key of zero")

    assert_raise ActiveRecord::RecordNotUnique do
      Post.create!(id: 0, title: "Test", body: "Try to create another post with primary key of zero")
    end
  end

  describe "with different language" do
    before do
      @default_language = connection.user_options_language
    end

    after do
      begin
        connection.execute("SET LANGUAGE #{@default_language}")
      rescue
        nil
      end
      connection.send :initialize_dateformatter
    end

    it "memos users dateformat" do
      begin
        connection.execute("SET LANGUAGE us_english")
      rescue
        nil
      end
      dateformat = connection.instance_variable_get(:@database_dateformat)
      assert_equal "mdy", dateformat
    end

    it "has a dateformatter" do
      assert Date::DATE_FORMATS[:_sqlserver_dateformat]
      assert Time::DATE_FORMATS[:_sqlserver_dateformat]
    end

    it "does a datetime insertion when language is german" do
      connection.execute("SET LANGUAGE deutsch")
      connection.send :initialize_dateformatter
      assert_nothing_raised do
        starting = Time.utc(2000, 1, 31, 5, 42, 0)
        ending = Time.new(2006, 12, 31)
        Task.create! starting: starting, ending: ending
      end
    end
  end

  describe "testing #lowercase_schema_reflection" do
    before do
      SSTestUpper.delete_all
      SSTestUpper.create COLUMN1: "Got a minute?", COLUMN2: 419
      SSTestUpper.create COLUMN1: "Favorite number?", COLUMN2: 69
    end

    after do
      connection.lowercase_schema_reflection = false
    end

    it "not lowercase schema reflection by default" do
      assert SSTestUpper.columns_hash["COLUMN1"]
      assert_equal "Got a minute?", SSTestUpper.first.COLUMN1
      assert_equal "Favorite number?", SSTestUpper.last.COLUMN1
      assert SSTestUpper.columns_hash["COLUMN2"]
    end

    it "lowercase schema reflection when set" do
      connection.lowercase_schema_reflection = true
      assert SSTestUppered.columns_hash["column1"]
      assert_equal "Got a minute?", SSTestUppered.first.column1
      assert_equal "Favorite number?", SSTestUppered.last.column1
      assert SSTestUppered.columns_hash["column2"]
    end

    it "destroys model with no associations" do
      connection.lowercase_schema_reflection = true

      assert_nothing_raised do
        discount = Discount.create!
        discount.destroy!
      end
    end

    it "destroys model with association" do
      connection.lowercase_schema_reflection = true

      assert_nothing_raised do
        post = Post.create!(title: "Setup", body: "Record to be deleted")
        post.destroy!
      end
    end
  end

  describe "identity inserts" do
    before do
      @identity_insert_sql = "INSERT INTO [funny_jokes] ([id],[name]) VALUES(420,'Knock knock')"
      @identity_insert_sql_unquoted = "INSERT INTO funny_jokes (id, name) VALUES(420, 'Knock knock')"
      @identity_insert_sql_unordered = "INSERT INTO [funny_jokes] ([name],[id]) VALUES('Knock knock',420)"
      @identity_insert_sql_sp = "EXEC sp_executesql N'INSERT INTO [funny_jokes] ([id],[name]) VALUES (@0, @1)', N'@0 int, @1 nvarchar(255)', @0 = 420, @1 = N'Knock knock'"
      @identity_insert_sql_unquoted_sp = "EXEC sp_executesql N'INSERT INTO funny_jokes (id, name) VALUES (@0, @1)', N'@0 int, @1 nvarchar(255)', @0 = 420, @1 = N'Knock knock'"
      @identity_insert_sql_unordered_sp = "EXEC sp_executesql N'INSERT INTO [funny_jokes] ([name],[id]) VALUES (@0, @1)', N'@0 nvarchar(255), @1  int', @0 = N'Knock knock', @1 = 420"

      @identity_merge_sql = "MERGE INTO [ships] WITH (UPDLOCK, HOLDLOCK) AS target USING ( SELECT * FROM ( SELECT [id], [name], ROW_NUMBER() OVER ( PARTITION BY [id] ORDER BY [id] DESC ) AS rn_0 FROM ( VALUES (101, N'RSS Sir David Attenborough') ) AS t1 ([id], [name]) ) AS ranked_source WHERE rn_0 = 1 ) AS source ON (target.[id] = source.[id]) WHEN MATCHED THEN UPDATE SET target.[name] = source.[name] WHEN NOT MATCHED BY TARGET THEN INSERT ([id], [name]) VALUES (source.[id], source.[name]) OUTPUT INSERTED.[id]"
      @identity_merge_sql_unquoted = "MERGE INTO ships WITH (UPDLOCK, HOLDLOCK) AS target USING ( SELECT * FROM ( SELECT id, name, ROW_NUMBER() OVER ( PARTITION BY id ORDER BY id DESC ) AS rn_0 FROM ( VALUES (101, N'RSS Sir David Attenborough') ) AS t1 (id, name) ) AS ranked_source WHERE rn_0 = 1 ) AS source ON (target.id = source.id) WHEN MATCHED THEN UPDATE SET target.name = source.name WHEN NOT MATCHED BY TARGET THEN INSERT (id, name) VALUES (source.id, source.name) OUTPUT INSERTED.id"
      @identity_merge_sql_unordered = "MERGE INTO [ships] WITH (UPDLOCK, HOLDLOCK) AS target USING ( SELECT * FROM ( SELECT [name], [id], ROW_NUMBER() OVER ( PARTITION BY [id] ORDER BY [id] DESC ) AS rn_0 FROM ( VALUES (101, N'RSS Sir David Attenborough') ) AS t1 ([name], [id]) ) AS ranked_source WHERE rn_0 = 1 ) AS source ON (target.[id] = source.[id]) WHEN MATCHED THEN UPDATE SET target.[name] = source.[name] WHEN NOT MATCHED BY TARGET THEN INSERT ([name], [id]) VALUES (source.[name], source.[id]) OUTPUT INSERTED.[id]"

      @identity_insert_sql_non_dbo = "INSERT INTO [test].[aliens] ([id],[name]) VALUES(420,'Mork')"
      @identity_insert_sql_non_dbo_unquoted = "INSERT INTO test.aliens ([id],[name]) VALUES(420,'Mork')"
      @identity_insert_sql_non_dbo_unordered = "INSERT INTO [test].[aliens] ([name],[id]) VALUES('Mork',420)"
      @identity_insert_sql_non_dbo_sp = "EXEC sp_executesql N'INSERT INTO [test].[aliens] ([id],[name]) VALUES (@0, @1)', N'@0 int, @1 nvarchar(255)', @0 = 420, @1 = N'Mork'"
      @identity_insert_sql_non_dbo_unquoted_sp = "EXEC sp_executesql N'INSERT INTO test.aliens (id, name) VALUES (@0, @1)', N'@0 int, @1 nvarchar(255)', @0 = 420, @1 = N'Mork'"
      @identity_insert_sql_non_dbo_unordered_sp = "EXEC sp_executesql N'INSERT INTO [test].[aliens] ([name],[id]) VALUES (@0, @1)', N'@0 nvarchar(255), @1  int', @0 = N'Mork', @1 = 420"
    end

    it "return quoted table_name to #query_requires_identity_insert? when INSERT sql contains id column" do
      assert_equal "[funny_jokes]", connection.send(:query_requires_identity_insert?, @identity_insert_sql)
      assert_equal "[funny_jokes]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_unquoted)
      assert_equal "[funny_jokes]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_unordered)
      assert_equal "[funny_jokes]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_sp)
      assert_equal "[funny_jokes]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_unquoted_sp)
      assert_equal "[funny_jokes]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_unordered_sp)

      assert_equal "[ships]", connection.send(:query_requires_identity_insert?, @identity_merge_sql)
      assert_equal "[ships]", connection.send(:query_requires_identity_insert?, @identity_merge_sql_unquoted)
      assert_equal "[ships]", connection.send(:query_requires_identity_insert?, @identity_merge_sql_unordered)

      assert_equal "[test].[aliens]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_non_dbo)
      assert_equal "[test].[aliens]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_non_dbo_unquoted)
      assert_equal "[test].[aliens]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_non_dbo_unordered)
      assert_equal "[test].[aliens]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_non_dbo_sp)
      assert_equal "[test].[aliens]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_non_dbo_unquoted_sp)
      assert_equal "[test].[aliens]", connection.send(:query_requires_identity_insert?, @identity_insert_sql_non_dbo_unordered_sp)
    end

    it "return false to #query_requires_identity_insert? for normal SQL" do
      [basic_insert_sql, basic_merge_sql, basic_update_sql, basic_select_sql].each do |sql|
        assert !connection.send(:query_requires_identity_insert?, sql), "SQL was #{sql}"
      end
    end

    it "find identity column using #identity_columns" do
      task_id_column = Task.columns_hash["id"]
      assert_equal task_id_column.name, connection.send(:identity_columns, Task.table_name).first.name
      assert_equal task_id_column.sql_type, connection.send(:identity_columns, Task.table_name).first.sql_type
    end

    it "return an empty array when calling #identity_columns for a table_name with no identity" do
      _(connection.send(:identity_columns, Subscriber.table_name)).must_equal []
    end
  end

  describe "quoting" do
    it "return 1 for #quoted_true" do
      assert_equal "1", connection.quoted_true
    end

    it "return 0 for #quoted_false" do
      assert_equal "0", connection.quoted_false
    end

    it "not escape backslash characters like abstract adapter" do
      string_with_backslashs = "\\n"
      assert_equal string_with_backslashs, connection.quote_string(string_with_backslashs)
    end

    it "quote column names with brackets" do
      assert_equal "[foo]", connection.quote_column_name(:foo)
      assert_equal "[foo]", connection.quote_column_name("foo")
      assert_equal "[foo].[bar]", connection.quote_column_name("foo.bar")
    end

    it "not quote already quoted column names with brackets" do
      assert_equal "[foo]", connection.quote_column_name("[foo]")
      assert_equal "[foo].[bar]", connection.quote_column_name("[foo].[bar]")
    end

    it "quote table names like columns" do
      assert_equal "[foo].[bar]", connection.quote_column_name("foo.bar")
      assert_equal "[foo].[bar].[baz]", connection.quote_column_name("foo.bar.baz")
    end

    it "surround string with national prefix" do
      assert_equal "N'foo'", connection.quote("foo")
    end

    it "escape all single quotes by repeating them" do
      assert_equal "N'''quotation''s'''", connection.quote("'quotation's'")
    end
  end

  describe "disabling referential integrity" do
    before do
      connection.disable_referential_integrity {
        SSTestHasPk.delete_all
        SSTestHasFk.delete_all
      }
      @parent = SSTestHasPk.create!
      @member = SSTestHasFk.create!(fk_id: @parent.id)
    end

    it "NOT ALLOW by default the deletion of a referenced parent" do
      SSTestHasPk.lease_connection.disable_referential_integrity {}
      assert_raise(ActiveRecord::StatementInvalid) { @parent.destroy }
    end

    it "ALLOW deletion of referenced parent using #disable_referential_integrity block" do
      assert_difference("SSTestHasPk.count", -1) do
        SSTestHasPk.lease_connection.disable_referential_integrity { @parent.destroy }
      end
    end

    it "again NOT ALLOW deletion of referenced parent after #disable_referential_integrity block" do
      assert_raise(ActiveRecord::StatementInvalid) do
        SSTestHasPk.lease_connection.disable_referential_integrity {}
        @parent.destroy
      end
    end

    it "not disable referential integrity for the same table twice" do
      tables = SSTestHasPk.lease_connection.tables_with_referential_integrity
      assert_equal tables.size, tables.uniq.size
    end
  end

  describe "database statements" do
    it "run the database consistency checker 'user_options' command" do
      skip "on azure" if connection_sqlserver_azure?
      keys = [:textsize, :language, :isolation_level, :dateformat]
      user_options = connection.user_options
      keys.each do |key|
        msg = "Expected key:#{key} in user_options:#{user_options.inspect}"
        assert user_options.key?(key), msg
      end
    end

    it "return a underscored key hash with indifferent access of the results" do
      skip "on azure" if connection_sqlserver_azure?
      user_options = connection.user_options
      assert_equal "read committed", user_options["isolation_level"]
      assert_equal "read committed", user_options[:isolation_level]
    end
  end

  describe "schema statements" do
    it "create integers when no limit supplied" do
      assert_equal "integer", connection.type_to_sql(:integer)
    end

    it "create integers when limit is 4" do
      assert_equal "integer", connection.type_to_sql(:integer, limit: 4)
    end

    it "create integers when limit is 3" do
      assert_equal "integer", connection.type_to_sql(:integer, limit: 3)
    end

    it "create smallints when limit is 2" do
      assert_equal "smallint", connection.type_to_sql(:integer, limit: 2)
    end

    it "create tinyints when limit is 1" do
      assert_equal "tinyint", connection.type_to_sql(:integer, limit: 1)
    end

    it "create bigints when limit is greater than 4" do
      assert_equal "bigint", connection.type_to_sql(:integer, limit: 5)
      assert_equal "bigint", connection.type_to_sql(:integer, limit: 6)
      assert_equal "bigint", connection.type_to_sql(:integer, limit: 7)
      assert_equal "bigint", connection.type_to_sql(:integer, limit: 8)
    end

    it "create floats when no limit supplied" do
      assert_equal "float", connection.type_to_sql(:float)
    end
  end

  describe "views" do
    # Using connection.views

    it "return an array" do
      assert_instance_of Array, connection.views
    end

    it "find SSTestCustomersView table name" do
      _(connection.views).must_include "sst_customers_view"
    end

    it "work with dynamic finders" do
      name = "MetaSkills"
      customer = SSTestCustomersView.create! name: name
      assert_equal customer, SSTestCustomersView.find_by_name(name)
    end

    it "not contain system views" do
      systables = ["sysconstraints", "syssegments"]
      systables.each do |systable|
        assert !connection.views.include?(systable), "This systable #{systable} should not be in the views array."
      end
    end

    it "allow the connection#view_information method to return meta data on the view" do
      view_info = connection.send(:view_information, "sst_customers_view")
      assert_equal("sst_customers_view", view_info["TABLE_NAME"])
      assert_match(/CREATE VIEW sst_customers_view/, view_info["VIEW_DEFINITION"])
    end

    it "allows connection#view_information to work with qualified object names" do
      view_info = connection.send(:view_information, "[activerecord_unittest].[dbo].[sst_customers_view]")
      assert_equal("sst_customers_view", view_info["TABLE_NAME"])
      assert_match(/CREATE VIEW sst_customers_view/, view_info["VIEW_DEFINITION"])
    end

    it "allows connection#view_information to work across databases when using qualified object names" do
      # College is defined in activerecord_unittest2 database.
      view_info = College.lease_connection.send(:view_information, "[activerecord_unittest].[dbo].[sst_customers_view]")
      assert_equal("sst_customers_view", view_info["TABLE_NAME"])
      assert_match(/CREATE VIEW sst_customers_view/, view_info["VIEW_DEFINITION"])
    end

    it "allow the connection#view_table_name method to return true table_name for the view" do
      assert_equal "customers", connection.send(:view_table_name, "sst_customers_view")
      assert_equal "topics", connection.send(:view_table_name, "topics"), "No view here, the same table name should come back."
    end

    it "allow the connection#view_table_name method to return true table_name for the view for other connections" do
      assert_equal "customers", College.lease_connection.send(:view_table_name, "[activerecord_unittest].[dbo].[sst_customers_view]")
      assert_equal "topics", College.lease_connection.send(:view_table_name, "topics"), "No view here, the same table name should come back."
    end
    # With same column names

    it "have matching column objects" do
      columns = ["id", "name", "balance"]
      assert !SSTestCustomersView.columns.blank?
      assert_equal columns.size, SSTestCustomersView.columns.size
      columns.each do |colname|
        assert_instance_of ActiveRecord::ConnectionAdapters::SQLServer::Column,
          SSTestCustomersView.columns_hash[colname],
          "Column name #{colname.inspect} was not found in these columns #{SSTestCustomersView.columns.map(&:name).inspect}"
      end
    end

    it "find identity column" do
      _(SSTestCustomersView.primary_key).must_equal "id"
      _(connection.primary_key(SSTestCustomersView.table_name)).must_equal "id"
      _(SSTestCustomersView.columns_hash["id"]).must_be :is_identity?
    end

    it "find default values" do
      assert_equal 0, SSTestCustomersView.new.balance
    end

    it "respond true to data_source_exists?" do
      assert SSTestCustomersView.lease_connection.data_source_exists?(SSTestCustomersView.table_name)
    end

    # With aliased column names

    it "have matching column objects" do
      columns = ["id", "pretend_null"]
      assert !SSTestStringDefaultsView.columns.blank?
      assert_equal columns.size, SSTestStringDefaultsView.columns.size
      columns.each do |colname|
        assert_instance_of ActiveRecord::ConnectionAdapters::SQLServer::Column,
          SSTestStringDefaultsView.columns_hash[colname],
          "Column name #{colname.inspect} was not found in these columns #{SSTestStringDefaultsView.columns.map(&:name).inspect}"
      end
    end

    it "find identity column" do
      _(SSTestStringDefaultsView.primary_key).must_equal "id"
      _(connection.primary_key(SSTestStringDefaultsView.table_name)).must_equal "id"
      _(SSTestStringDefaultsView.columns_hash["id"]).must_be :is_identity?
    end

    it "find default values" do
      assert_equal "null", SSTestStringDefaultsView.new.pretend_null,
        SSTestStringDefaultsView.columns_hash["pretend_null"].inspect
    end

    it "respond true to data_source_exists?" do
      assert SSTestStringDefaultsView.lease_connection.data_source_exists?(SSTestStringDefaultsView.table_name)
    end

    # That have more than 4000 chars for their definition

    it "cope with null returned for the definition" do
      assert_nothing_raised { SSTestStringDefaultsBigView.columns }
    end

    it "using alternate view definition still be able to find real default" do
      assert_equal "null", SSTestStringDefaultsBigView.new.pretend_null,
        SSTestStringDefaultsBigView.columns_hash["pretend_null"].inspect
    end
  end

  describe "database_prefix_remote_server?" do
    after do
      connection_options.delete(:database_prefix)
    end

    it "returns false if database_prefix is not configured" do
      assert_equal false, connection.database_prefix_remote_server?
    end

    it "returns true if database_prefix has been set" do
      connection_options[:database_prefix] = "server.database.schema."
      assert_equal true, connection.database_prefix_remote_server?
    end

    it "returns false if database_prefix has been set incorrectly" do
      connection_options[:database_prefix] = "server.database.schema"
      assert_equal false, connection.database_prefix_remote_server?
    end
  end

  it "in_memory_oltp" do
    if ENV["IN_MEMORY_OLTP"] && connection.supports_in_memory_oltp?
      _(SSTMemory.primary_key).must_equal "id"
      _(SSTMemory.columns_hash["id"]).must_be :is_identity?
    else
      skip "supports_in_memory_oltp? => false"
    end
  end

  describe "block writes to a database" do
    def setup
      @conn = ActiveRecord::Base.lease_connection
    end

    def test_errors_when_an_insert_query_is_called_while_preventing_writes
      assert_raises(ActiveRecord::ReadOnlyError) do
        ActiveRecord::Base.while_preventing_writes do
          @conn.insert("INSERT INTO [subscribers] ([nick]) VALUES ('aido')")
        end
      end
    end

    def test_errors_when_an_update_query_is_called_while_preventing_writes
      @conn.insert("INSERT INTO [subscribers] ([nick]) VALUES ('aido')")

      assert_raises(ActiveRecord::ReadOnlyError) do
        ActiveRecord::Base.while_preventing_writes do
          @conn.update("UPDATE [subscribers] SET [subscribers].[name] = 'Aidan' WHERE [subscribers].[nick] = 'aido'")
        end
      end
    end

    def test_errors_when_a_delete_query_is_called_while_preventing_writes
      @conn.execute("INSERT INTO [subscribers] ([nick]) VALUES ('aido')")

      assert_raises(ActiveRecord::ReadOnlyError) do
        ActiveRecord::Base.while_preventing_writes do
          @conn.execute("DELETE FROM [subscribers] WHERE [subscribers].[nick] = 'aido'")
        end
      end
    end

    def test_doesnt_error_when_a_select_query_is_called_while_preventing_writes
      @conn.execute("INSERT INTO [subscribers] ([nick]) VALUES ('aido')")

      ActiveRecord::Base.while_preventing_writes do
        assert_equal 1, @conn.execute("SELECT * FROM [subscribers] WHERE [subscribers].[nick] = 'aido'").count
      end
    end
  end

  describe "table is in non-dbo schema" do
    it "records can be created successfully" do
      assert_difference("Alien.count", 1) do
        Alien.create!(name: "Trisolarans")
      end
    end

    it "records can be inserted using SQL" do
      assert_difference("Alien.count", 2) do
        Alien.lease_connection.exec_insert("insert into [test].[aliens] (id, name) VALUES(1, 'Trisolarans'), (2, 'Xenomorph')")
      end
    end
  end

  describe "table names contains spaces" do
    it "records can be created successfully" do
      assert_difference("TableWithSpaces.count", 1) do
        TableWithSpaces.create!(name: "Bob")
      end
    end
  end

  describe "exec_insert" do
    it "values clause should be case-insensitive" do
      assert_difference("Post.count", 4) do
        first_insert = connection.exec_insert("INSERT INTO [posts] ([id],[title],[body]) VALUES(100, 'Title', 'Body'), (102, 'Title', 'Body')")
        second_insert = connection.exec_insert("INSERT INTO [posts] ([id],[title],[body]) values(113, 'Body', 'Body'), (114, 'Body', 'Body')")

        assert_equal first_insert.rows.map(&:first), [100, 102]
        assert_equal second_insert.rows.map(&:first), [113, 114]
      end
    end
  end

  describe "mismatched foreign keys error" do
    def setup
      @conn = ActiveRecord::Base.lease_connection
    end

    it "raises an error when the foreign key is mismatched" do
      error = assert_raises(ActiveRecord::MismatchedForeignKey) do
        @conn.add_reference :engines, :old_car
        @conn.add_foreign_key :engines, :old_cars
      end

      assert_match(
        %r{Column 'old_cars\.id' is not the same data type as referencing column 'engines\.old_car_id' in foreign key '.*'},
        error.message
      )
      assert_not_nil error.cause
      assert_equal @conn.pool, error.connection_pool
    ensure
      begin
        @conn.execute("ALTER TABLE engines DROP COLUMN old_car_id")
      rescue
        nil
      end
    end
  end

  describe "placeholder conditions" do
    it "using time placeholder" do
      assert_equal Task.where("starting < ?", Time.now).count, 1
    end

    it "using date placeholder" do
      assert_equal Task.where("starting < ?", Date.today).count, 1
    end

    it "using date-time placeholder" do
      assert_equal Task.where("starting < ?", DateTime.current).count, 1
    end
  end

  describe "distinct select query" do
    it "generated SQL does not contain unnecessary alias projection" do
      sqls = capture_sql do
        Post.includes(:comments).joins(:comments).first
      end
      assert_no_match(/AS alias_0/, sqls.first)
    end
  end
end