ORACLE表test01字段的操作
SQL> create table test01 (NO NUMBER NOT NULL,NAME VARCHAR(30)); 1.修改表名称 SQL> alter table test01 rename to test02; Table altered. SQL> desc test01 ERROR: ORA-04043: object test01 does not exist SQL> desc test02 Name Null? Type ----------------------------------------- -------- ---------------------------- NO NOT NULL NUMBER NAME VARCHAR2(30) 2.更改表列名称 SQL> alter table test01 rename column no to nod; Table altered. SQL> desc test01 Name Null? Type ----------------------------------------- -------- ---------------------------- NOD NOT NULL NUMBER NAME VARCHAR2(30) 3.修改表test01的NOD字段类型 SQL> alter table test01 modify nod char; Table altered. SQL> desc test01 Name Null? Type ----------------------------------------- -------- ---------------------------- NOD NOT NULL CHAR(1) NAME VARCHAR2(30) 3.给表test01增加单列dept SQL> alter table test01 add dept varchar2(100); Table altered. SQL> desc test01 Name Null? Type ----------------------------------------- -------- ---------------------------- NOD NOT NULL CHAR(1) NAME VARCHAR2(30) DEPT VARCHAR2(100) 4.给表test01增加多列sex,ages SQL> alter table test01 add (sex char(2),ages number); Table altered. SQL> desc test01 Name Null? Type ----------------------------------------- -------- ---------------------------- NOD NOT NULL CHAR(1) NAME VARCHAR2(30) DEPT VARCHAR2(100) SEX CHAR(2) AGES NUMBER 5.同时添加和修改表test01的列 SQL> desc test01 Name Null? Type ----------------------------------------- -------- ---------------------------- NOD NOT NULL CHAR(1) NAME VARCHAR2(30) DEPT VARCHAR2(100) SEX CHAR(2) AGES NUMBER SQL> alter table test01 add (new01 char,new02 char) 2 modify (nod number,name number,dept number ,sex number,ages char); Table altered. SQL> desc test01 Name Null? Type ----------------------------------------- -------- ---------------------------- NOD NOT NULL NUMBER NAME NUMBER DEPT NUMBER SEX NUMBER AGES CHAR(1) NEW01 CHAR(1) NEW02 CHAR(1) 6.***表test01的列 SQL> alter table test01 drop column dept cascade constraints; alter table test01 drop column dept cascade constraints * ERROR at line 1: ORA-12988: cannot drop column from table owned by SYS 由于我的表是在sys下建立的所以不能***sys的表的列, 其他用户可以参考 以下命令 如在scott用户下的表***列 SQL > alter table scott.test01 drop column dept cascade constraints;
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