To add a columnto an existing table, use the ALTERTABLE...ADD statement. The followingstatement alters the hr.admin_emp table to add a new columnnamed bonus: ALTER TABLE hr.admin_emp ADD (bonus NUMBER (7,2)); If a new columnis added to a table, the column is initially NULL unless...
Add a new column to table with theALTER TABLE… ADDstatement. Set the column properties in the same command itself. As an example, add columnc1of data typeINTwith default value of1. Set the column as non-nullable with theNOT NULLclause. Set thec1column as the primary key with thePRIMARY...
SQL> select * from user_tab_comments where TABLE_NAME=’EMPLOYEES’; TABLE_NAME TABLE_TYPE COMMENTS EMPLOYEES TABLE 7.删除列级说明,也是将其置为空 SQL> comment on column employees.salary is ”; Comment added SQL> select * from user_col_comments where TABLE_NAME=’EMPLOYEES’; TABLE_NAME C...
To add a new column to a table, you use the ALTER TABLE statement as follows: ALTER TABLE table_name ADD column_name data_type constraint; Code language: SQL (Structured Query Language) (sql) In this statement: First, you specify the name of the table, to which you want to add the ...
删除字段的语法: ALTER TABLE table_name(MODIFY column_name column_type , ... ); 例子: 使用一个SQL语句同时添加三个字段: 代码如下: 1 2 3 4 5 6 7 altertabletest1 add( namevarchar2(30)default‘无名氏'notnull, ageintegerdefault22notnull, has...
SQL> selectcount(*) from t; 1000000 SQL> altertable t add add_h number not null; alter table tadd add_h number not null * ERROR at line1: ORA-01758:table must be empty to add mandatory (NOT NULL) column 新增一个仅有NOT NULL约束,没有默认值的字段,则需要表为空。顺带提一句,删除表...
ALTER TABLE old_table_name RENAME TO new_table_name;(大写为系统命令) 2:使用rename修改 SQL> select tname from tab ; TNAME ——— TEST SQL> rename test to temp ; Table renamed. SQL> select tname from tab ; TNAME ——— TEMP 注意: rname只能修改自己schema下面...
Oracle Goldengate marked following column as key columns on table TEST.TEST1: ID. ---为表test.test2添加同步日志 GGSCI (rac19b as ogg@testdb) 5> add trandata test.test2 2022-10-13 13:09:04 INFO OGG-15132 Logging of supplemental redo data enabled for table TEST.TEST2. 2022-10-13 13...
alter table 表名 add 字段名 字段类型; 示例:在system空间的test表中增加avg字段; alter table system.test add avg number; 2.4.5 删除字段 alter table 表名 drop column字段名; 示例:在system空间的test表中删除avg字段; alter table system.test drop column avg; ...
在执行add column 之前,我们启用10046 事件跟踪一下这个过程: SQL> oradebug setmypid Statement processed. SQL> oradebug event 10046 trace name context forever,level 8; Statement processed. --执行操作 SQL> alter table t1 add tel varchar2(20)default '13888888888' not null; ...