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1. offlineÊý¾ÝÎļþËù±»°üº¬µÄtablespace£¬
alter tablespace testts offline;
2. rename ÔÓеÄdatafileÖ¸Ïòеķ¾¶
#cp /opt/oracle/oradata/orcl/testts01.dbf /opt/oracle/oradata/test/testts01.dbf
SQL>alter tablespace testts rename datafile ‘/opt/oracle/oradata/orcl/testts01.dbf’
to ‘/opt/oracle/oradata/test/testts01.dbf’;
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alter tablespace testts rename datafile 3
to ‘/opt/oracle/oradata/test/testts01.dbf’;
3. onlineÒѾ¸ÄºÃµÄtablespace
SQL> alter tablespace testts online;
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1.ASCII
·µ»ØÓëÖ¸¶¨µÄ×Ö·û¶ÔÓ¦µÄÊ®½øÖÆÊý;
SQL> select ascii(A) A,ascii(a) a,ascii(0) zero,ascii( ) space from dual;
A A ZERO SPACE
--------- --------- --------- ---------
65 97 48 32
2.CHR
¸ø³öÕûÊý,·µ»Ø¶ÔÓ¦µÄ×Ö·û;
SQL> select chr(54740) zhao,chr(65) chr65 from dual;
......
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all±íʾ¶ÔËùÓеÄÖµÇ󯽾ùÖµ,distinctÖ»¶Ô²»Í¬µÄÖµÇ󯽾ùÖµ
SQLWKS> create table table3(xm varchar(8),sal number(7,2));
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SQLWKS> insert into table3 values(gao,1111.11);
SQLWKS> insert into table3 values(gao,1111.11);
SQLWKS> insert into table3 values(zhu ......
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select trunc(5.75),trunc(5.75,1),trunc(5.75,-1),trunc(556.234,-2) from dual;
Êä³ö:
TRUNC(5.75) TRUNC(5.75,1) TRUNC(5.75,-1) TRUNC(556.234,-2)
----------- ------------- -------------- ----- ......
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b. COST £¨»ùÓڳɱ¾£©
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TO_DATE¸ñʽ
Day:
dd number 12
dy abbreviated fri
day spelled out friday
ddspth spelled out, ordinal twelfth
Month:
mm number 03
mon abbreviated mar ......