SELECT TO_CHAR(124.3456,'0000.00') FROM dual ;
SELECT TO_CHAR(124.3456,'9999.99') FROM dual ;
SELECT TO_CHAR(124.3456,'$9999.99') FROM dual ;
SELECT TO_CHAR(SYSDATE,'YYYY-MM-DD HH:MI:SS') FROM dual ;
SELECT TO_CHAR(SYSDATE,'YYYY"年"MM"月"DD"日" HH:MI:SS') FROM dual;
SELECT TO_DATE('2005-12-06','yyyy-mm-dd') FROM dual;
select rowid,emp.* from scott.emp;
select rownum,emp.* from scott.emp;
select * from (select rownum rnum,s.* from scott.emp s ) where rnum=3;
select nvl(comm,0) from scott.emp;
select distinct job from scott.emp;
create table emp
as
select * from scott.emp;
select table_name from user_all_tables a
where a.num_rows>10 ;
select * from sun.tuser;
insert into sun.tuser(userid,username,pwd)
values(18,'1777','1777');
savepoint aa;
insert into sun.tuser(userid,username,pwd)
values(19,'1777','1777');
rollback to aa;
select * from sun.tuser;
commit
select * from scott.emp;
select count(*) from scott.emp
select * from scott.emp
union
select * from scott.emp
where job='CLERK'
select * from scott.emp
union ALL
select * from scott.emp
where job='CLERK'
select * from scott.emp
INTERSECT
select * from scott.emp
where job='CLERK'
select * from scott.emp
MINUS
select * from scott.emp
where job='CLERK'
select ename, job,sal,
row_number()over(partition by job order by sal desc ) "number",
dense_rank()over(partition by job order by sal desc ) "dense_rank",
rank()over(partition by job order by sal desc ) "rank"
from emp;
select ename, job,sal,
row_number()over( order by sal desc ) "number",
dense_rank()over(order by sal desc ) "dense_rank",
rank()over( order by sal desc ) "rank"
from emp;
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