{"description":"Oracle \u30cc\u30eb\u3068\u7a7a\u6587\u5b57\u306f\u540c\u3058 MySQL \u30cc\u30eb\u3068\u7a7a\u6587\u5b57\u306f\u7570\u306a\u308b create table tab15(col1 int,col2 varchar(10));insert into tab15 values(1,'');insert into tab15 values(2,NULL); select * from tab15; select * from tab15 where col2 = '';select * from tab15 where col2 is null; PostgreSQL \u30cc\u30eb\u3068\u7a7a\u6587\u5b57\u306f\u7570\u306a\u308b create table tab15(col1 int,col2 var\u2026","published":"2019-05-06 13:57:15","blog_title":"HTN20190109\u306e\u65e5\u8a18","height":"190","provider_url":"https://hatena.blog","url":"https://htn20190109.hatenablog.com/entry/2019/05/06/135715","width":"100%","author_name":"HTN20190109","blog_url":"https://htn20190109.hatenablog.com/","categories":["DB"],"author_url":"https://blog.hatena.ne.jp/HTN20190109/","version":"1.0","title":"\u30cc\u30eb\u306e\u6271\u3044","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fhtn20190109.hatenablog.com%2Fentry%2F2019%2F05%2F06%2F135715\" title=\"\u30cc\u30eb\u306e\u6271\u3044 - HTN20190109\u306e\u65e5\u8a18\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","image_url":null,"provider_name":"Hatena Blog","type":"rich"}