更新字段名 alter table TABLE_NAME rename column column_old to column_new; 添加字段 alter table TABLE_NAME add (COLUMN_NAME varchar(10)); 删除字段 alter table TABLE_NAME drop column COLUMN_NAME; 添加字段并附值 alter table TABLE_NAME add (COLUMN_NAME NUMBER(1) DEFAULT 1); 修改字段值 updat...
不同的数据库管理系统对ALTER命令的实现有所不同,但基本功能大体相同。在Oracle数据库中,ALTER命令的语法和MySQL类似,但有一些特定的功能。例如,Oracle允许使用ALTER命令来修改表的存储参数和启用或禁用触发器: ALTER TABLE table_name MODIFY column_name datatype; ALTER TABLE table_name ADD CONSTRAINT constraint_n...
添加字段的语法:alter table tablename add (column datatype [default value][null/not null],….); 修改字段的语法:alter table tablename modify (column datatype [default value][null/not null],….); 删除字段的语法:alter table tablename drop (column); 添加、修改、删除多列的话,用逗号隔开。 使...
Oracle中 Alter Table 语句的使用 alter table 的功能是修改表格。包括重名命,加减字段,修改字段类型和大小,处理 约束等等。本例子之处理表名和字段,代码如下: create table liu(a varchar2 ( 20 ),b number ( 2 )) alter table liu rename to jin rename jin to cai alter table cai add c varchar2 ( ...
To learn whether a logfile has been designated for online or standby database use, query the TYPE column of the V$LOGFILE dynamic performance view. THREAD The THREAD clause is applicable only if you are using Oracle with the Real Application Clusters option in parallel mode. integer is the ...
For integer1, specify the value of the SID column. For integer2, specify the value of the SERIAL# column. If the session is performing some activity that must be completed, such as waiting for a reply from a remote database or rolling back a transaction, Oracle waits for this activity...
oracle中alter table add column遇见详解 在Oracle数据库中,ALTER TABLE语句用于修改现有表的结构。如果你想向表中添加新列,可以使用ADD COLUMN子句。 以下是使用ALTER TABLE ADD COLUMN语句的基本语法: ALTERTABLEtable_namesql ADDcolumn_name data_type [constraint]; 其中: table_name是要修改的表的名称。 column...
Oracle 11g R2 alter table add column Oracle官方文档中关于alter table add column有下面的描述 https://docs.oracle.com/cd/E11882_01/server.112/e25494/tables.htm#ADMIN11005 个人理解纯粹是添加新列带有默认值的,如果不带默认值的,应该非常快就完成了。之前生成库160G的表,添加新列不到1秒就完成。
In this section of the article, we will discuss how we can create an index in the Oracle database. Let us take a look into the syntax of how to create an INDEX in Oracle first. CREATE INDEX index_name ON table_name(column1,column2,...,columnN); ...
PRIMARY KEY以及EXCLUDE约束中的index_parameters是: [ INCLUDE ( column_name [, ... ] ) ] [ WITH ( storage_parameter [= value] [, ... ] ) ] [ USING INDEX TABLESPACE tablespace_name ] exclude_element in an EXCLUDE constraint is: { column_name | ( expression ) } [ opclass ] [ ...