text: IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = 'Posts')
  BEGIN
  	CREATE TABLE Posts (
  		Id BIGINT IDENTITY(1,1) NOT NULL,
  		Date DATETIME NOT NULL,
  		Content VARCHAR(MAX) NOT NULL,
  		SenderId UNIQUEIDENTIFIER NOT NULL,
  		CONSTRAINT PK_Posts PRIMARY KEY (Id),
  		CONSTRAINT FK_Posts_SenderId_Users_Id FOREIGN KEY (SenderId) REFERENCES Users(Id)
  	);
  END
  
  IF NOT EXISTS (SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 'Comments' AND COLUMN_NAME = 'PostId' AND TABLE_SCHEMA = 'DBO')
  BEGIN
  	ALTER TABLE Comments ADD PostId BIGINT NOT NULL;
  	ALTER TABLE Comments ADD CONSTRAINT FK_Comments_PostId_Posts_Id FOREIGN KEY (PostId) REFERENCES Posts(Id);
  END