text: CREATE TABLE Activity (
      Id int IDENTITY(1,1) PRIMARY KEY,
      AccountId int NOT NULL,
      ActivityTypeId int NOT NULL,
      Amount BIGINT NOT NULL,
      CreateDate DATETIME DEFAULT GETDATE()
  );
  
  ALTER TABLE dbo.Activity
  ADD CONSTRAINT FK_AccountId FOREIGN KEY(AccountId) REFERENCES dbo.Balance(AccountId);
  
  ALTER TABLE dbo.Activity
  ADD CONSTRAINT FK_ActivityTypeId FOREIGN KEY(ActivityTypeId) REFERENCES dbo.ActivityType(Id);