(转)Oracle/Mysql/SqlServer函数区别
1.类型转换 ????
–Oracle??select?to_number(‘123’)?from?dual;??–123;??
?select?to_char(33)?from?dual;???????–33;??
select?to_date(‘2004-11-27’,‘yyyy/mm/dd’)?from?dual;–2004-11-27????
–Mysql??select?cast(‘123’?as?signed?integer);???–123???
select?cast(33?as?char(2));?????–33；??
select?to_days(‘2000-01-01’);???????–730485????
–SqlServer???select?cast(‘123’?as?decimal(30,2));????
–123.00??select?cast(33?as?char(2));?????–33；??
select?convert(varchar(12)?,?getdate(),?120) ???
?2.四舍五入函数区别? ????
–Oracle??select?round(12.86*10)/10?from?dual;????–12.9????
–Mysql??select?format(12.89,1);?????????–12.9????
?–SqlServer??select?round(12.89,1);??????????–12.9?????
3.日期时间函数 ????
–Oracle??select?sysdate?from?dual;???????–日期时间?????
–Mysql??select?sysdate();???????????–日期时间???
select?current_date();??????????–日期????
–SqlServer??select?getdate();???????????<span style="
