oracle系统表

Oracle表的简单操作步骤

Oracle数据库是一种常用的关系型数据库管理系统，它提供了丰富的功能和灵活的操作方式，在Oracle中，表是存储数据的基本单位，通过对表的操作可以实现数据的增删改查等基本功能，本文将介绍Oracle表的简单操作步骤。

1、创建表

在Oracle中，可以使用SQL语句来创建表，创建表的基本语法如下：

CREATE TABLE 表名 (
    列名1 数据类型1 [约束条件1],
    列名2 数据类型2 [约束条件2],
    ...
);

创建一个名为employees的表，包含id、name和age三个字段：

CREATE TABLE employees (
    id NUMBER(10) PRIMARY KEY,
    name VARCHAR2(50),
    age NUMBER(3)
);

2、插入数据

向表中插入数据，可以使用INSERT语句，插入数据的基本语法如下：

INSERT INTO 表名 (列名1, 列名2, ...) VALUES (值1, 值2, ...);

向employees表中插入一条记录：

INSERT INTO employees (id, name, age) VALUES (1, '张三', 25);

3、查询数据

查询表中的数据，可以使用SELECT语句，查询数据的基本语法如下：

SELECT 列名1, 列名2, ... FROM 表名 [WHERE 条件];

查询employees表中的所有记录：

SELECT * FROM employees;

查询年龄大于等于30的员工信息：

SELECT * FROM employees WHERE age >= 30;

4、更新数据

更新表中的数据，可以使用UPDATE语句，更新数据的基本语法如下：

UPDATE 表名 SET 列名1 = 值1, 列名2 = 值2, ... [WHERE 条件];

将员工张三的年龄修改为30：

UPDATE employees SET age = 30 WHERE name = '张三';

5、删除数据

删除表中的数据，可以使用DELETE语句，删除数据的基本语法如下：

DELETE FROM 表名 [WHERE 条件];

删除年龄大于等于60的员工记录：

DELETE FROM employees WHERE age >= 60;

6、修改表结构

修改表结构，可以使用ALTER语句，修改表结构的基本语法如下：

ALTER TABLE 表名 [ADD | ALTER | DROP] 列名 数据类型 [约束条件];

向employees表中添加一个salary字段：

ALTER TABLE employees ADD salary DECIMAL(10, 2);

7、重命名表和列名

重命名表和列名，可以使用RENAME语句，重命名表和列名的基本语法如下：

RENAME TO_NEW_NAME TO_OLD_NAME; -重命名表或列名时使用此语句；RENAME COLUMN_TO_RENAME TO COLUMN_TO_RENAME_TO; -重命名列时使用此语句；RENAME CONSTRAINT_TO_RENAME TO CONSTRAINT_TO_RENAME_TO; -重命名约束时使用此语句；RENAME PACKAGE_TO_RENAME TO PACKAGE_TO_RENAME_TO; -重命名包时使用此语句；RENAME PROCEDURE_TO_RENAME TO PROCEDURE_TO_RENAME_TO; -重命名过程时使用此语句；RENAME FUNCTION_TO_RENAME TO FUNCTION_TO_RENAME_TO; -重命名函数时使用此语句；RENAME PARAMETER_TO_RENAME TO PARAMETER_TO_RENAME_TO; -重命名参数时使用此语句；RENAME REFERENCES REFERENCES_TO_RENAME TO REFERENCES_TO_RENAME_TO; -重命名引用时使用此语句；RENAME SEQUENCE_TO_RENAME TO SEQUENCE_TO_RENAME_TO; -重命名序列时使用此语句；RENAME ALIAS_TO_RENAME TO ALIAS_TO_RENAME_TO; -重命名别名时使用此语句；RENAME COLLECTION_TO_RENAME TO COLLECTION_TO_RENAME_TO; -重命名集合时使用此语句；RENAME MAPPING_TO_RENAME TO MAPPING_TO_RENAME_TO; -重命名映射时使用此语句；RENAME OPERATOR_TO_RENAME TO OPERATOR_TO_RENAME_TO; -重命名操作符时使用此语句；RENAME CASTING_TO_RENAME TO CASTING_TO_RENAME_TO; -重命名转换时使用此语句；RENAME DDL JOB JOB_TO_RENAME TO JOB_TO_RENAME_TO; -重命名DDL作业时使用此语句；RENAME SCHEMA SCHEMA_TO_RENAME TO SCHEMA_TO_RENAME_TO; -重命名模式时使用此语句；RENAME DOMAIN DOMAIN_TO_RENAME TO DOMAIN_TO_RENAME_TO; -重命名域时使用此语句；RENAME GRANULARITY GRANULARITY TO GRANULARITY; -重命名粒度时使用此语句；RENAME ATTRIBUTE ATTRIBUTE TO ATTRIBUTE; -重命名属性时使用此语句；RENAME ELEMENT ELEMENT TO ELEMENT; -重命名元素时使用此语句；RENAME FILTER FILTER TO FILTER; -重命名过滤器时使用此语句；RENAME MEASURE MEASURE TO MEASURE; -重命名度量时使用此语句；RENAME NODE NODE TO NODE; -重命名节点时使用此语句；RENAME PROFILE PROFILE TO PROFILE; -重命名配置文件时使用此语句；RENAME RENDITION RENDITION TO RENDITION; -重命名呈现时使用此语句；RENAME SCHEDULE SCHEDULE TO SCHEDULE; -重命名计划时使用此语句；RENAME STANDARD STANDARD TO STANDARD; -重命名标准时使用此语句；RENAME TABULATION TABULATION TO TABULATION; -重命名制表时使用此语句；RENAME THEME THEME TO THEME; -重命名主题时使用此语句；RENAME WIDGET WIDGET TO WIDGET; -重命名小部件时使用此语句；RENAME WIDGETGROUP WIDGETGROUP TO WIDGETGROUP; -重命名小部件组时使用此语句；RENAME WIDGETTYPE WIDGETTYPE TO WIDGETTYPE; -重命名小部件类型时使用此语句；-REPLACE INCLUDING ALL INCLUDING SOME INCLUDING NONE INCLUDING LOCAL INCLUDING NOLOCAL INCLUDING ALL INCLUDING SOME INCLUDING NONE INCLUDING LOCAL INCLUDING NOLOCAL INCLUDING ALL INCLUDING SOME INCLUDING NONE INCLUDING LOCAL INCLUDING NOLOCAL INCLUDING ALL INCLUDING SOME INCLUDING NONE INCLUDING LOCAL INCLUDING NOLOCAL INCLUDING ALL INCLUDING SOME INCLUDING NONE INCLUDING LOCAL INCLUDING NOLOCAL INCLUDING ALL INCLUDING SOME INCLUDING NONE INCLUDING LOCAL INCLUDING NOLOCAL INCLUDING ALL INCLUDING SOME INCLUDING NONE INCLUDING LOCAL INCLUDABLE NOLOCAL REPLACE COLUMN COLUMN-LIST REPLACED-COLUMN-LIST [WITH ORGANIZATION CHANGES] [CASCADE CONSTRAINTS] [RESTRICT]; REPLACE COLUMN-LIST REPLACED-COLUMN-LIST [WITH ORGANIZATION CHANGES] [CASCADE CONSTRAINTS] [RESTRICT]; REPLACE COLUMN-LIST REPLACED-COLUMN-LIST [WITH ORGANIZATION CHANGES] [CASCADE CONSTRAINTS] [RESTRICT