Creating tables and columns in mysql database only if they do not exist

columnNotExist.sql

-- Creating tables and columns in mysql database only if they do not exist
-- Создание таблиц и колонок в базе данных mysql только если их не существует
-- VARIANT 1
-- Function columnExists (check column in table)
DROP FUNCTION IF EXISTS columnExists;
DELIMITER //

CREATE FUNCTION columnExists(t_table char(255),t_column char(255)) RETURNS boolean NOT DETERMINISTIC
BEGIN	
	SET @datatable := t_table, @datacolumn := t_column;
	IF  (SELECT count(*)  FROM information_schema.COLUMNS WHERE COLUMN_NAME=@datacolumn AND TABLE_NAME=@datatable)  THEN 
    		return false;
	ELSE
		return true;
    END  IF;
END    
//
DELIMITER ;

-- Create table newsletters
CREATE TABLE IF NOT EXISTS newsletters 
	(id int(11) NOT NULL AUTO_INCREMENT,
	PRIMARY KEY (id)
); 

-- Create safely columns
set @query = IF(columnExists('newsletters','email'), "ALTER TABLE newsletters ADD email varchar(255) NOT NULL","SELECT false");
prepare stmt from @query;EXECUTE stmt;
set @query = IF(columnExists('newsletters','status'), "ALTER TABLE newsletters ADD status int(11) NOT NULL","SELECT false");
prepare stmt from @query;EXECUTE stmt;
set @query = IF(columnExists('newsletters','created_at'), "ALTER TABLE newsletters ADD created_at int(11) NOT NULL","SELECT false");
prepare stmt from @query;EXECUTE stmt;
set @query = IF(columnExists('newsletters','updated_at'), "ALTER TABLE newsletters ADD updated_at int(11) NOT NULL","SELECT false");
prepare stmt from @query;EXECUTE stmt;

Alternative variant
-- VARIANT 3
DROP FUNCTION IF EXISTS columnExists;
DELIMITER //

CREATE FUNCTION columnExists(t_table char(255),t_column char(255)) RETURNS boolean NOT DETERMINISTIC
BEGIN
SET @DataTable := t_table, @DataColumn := t_column;
IF (SELECT count(*) FROM information_schema.COLUMNS WHERE COLUMN_NAME=@DataColumn AND TABLE_NAME=@DataTable) THEN
return false;
ELSE
return true;
END IF;
END
//
DELIMITER ;

DROP PROCEDURE IF EXISTS upgrade_database_1_0_to_2_0;
DELIMITER
//
CREATE PROCEDURE upgrade_database_1_0_to_2_0()
BEGIN
-- add a column safely
IF (columnExists('newsletters','ida') ) THEN
ALTER TABLE newsletters ADD ida varchar(2048) NOT NULL DEFAULT '';
END IF;
END
//
DELIMITER ;
CALL upgrade_database_1_0_to_2_0();