Oracle 数据库与 MSSQL 语言比较

	Oracle	MS sql
赋值	select col1 into v_name from employee	select @name= name from employee
申明	Declare v_user varchar2;	Declare @user varchar(200);
用现有表创建表	create table newTable as select * from oldTable;	select * into newTable from oldTable
选择前Ｎ行	select *  from (select * from table order by Id) a where rownum<=N;	select top N * from table
自动增加Ｉｄ	create trigger on table before insert for each row is begin select squence.nextval into v_newId from dual; :new.Id := v_newId; end; 需要建立一个序列	设置一个列为自动增长即可
连接表更新	update table1 a set a.col1 = (select col2 from table2 b where a.col1= b.col2);	update a set a.col1 =b.col2 from table1 a join table2 b on a.cola = b.colb
使用游标	declare v_name varchar2(20); cursor myCursor is select name from employee; begin open myCursor; loop fetch myCursor into v_name; --do somethings; exit when myCursor%NotFound; end loop; close myCursor;