Home Database Mysql Tutorial 一个完整的Oracle建表的例子

一个完整的Oracle建表的例子

Jun 07, 2016 pm 05:05 PM
database

建表一般来说是个挺简单的事情,但是Oracle的建表语句有很多可选的参数,有些我们可能平时不太用,用的时候又不知道怎么用,这里

建表一般来说是个挺简单的事情,但是Oracle的建表语句有很多可选的参数,有些我们可能平时不太用,,用的时候又不知道怎么用,这里就写一个较完整的建表的例子:

CREATE TABLE banping
  (id  NUMBER(5) 
       CONSTRAINT banping_id_pk PRIMARY KEY, 
   last_name VARCHAR2(10) 
       CONSTRAINT banping_last_name_nn NOT NULL,
   first_name VARCHAR2(10) NOT NULL UNIQUE,
   userid VARCHAR2(8) 
       CONSTRAINT banping_userid_uk UNIQUE,
  start_date DATE DEFAULT SYSDATE,
  title VARCHAR2(10),
  dept_id NUMBER(7)
       CONSTRAINT banping_dept_id_fk REFERENCES dept(id),
  salary NUMBER(11,2),
user_type VARCHAR2(4)
      CONSTRAINT banping_user_type_ck CHECK
       (user_type IN('IN','OUT')),
CONSTRAINT banping_uk_title UNIQUE (title,salary)
 )
INITRANS 1 MAXTRANS 255
PCTFREE  20  PCTUSED  50
STORAGE( INITIAL  1024K  NEXT  1024K  PCTINCREASE  0  MINEXTENTS  1  MAXEXTENTS  5)
TABLESPACE  data

解释说明如下:
语法

CREATE  TABLE  [schema.]table
(column  datatype [, column  datatype] … )
[TABLESPACE  tablespace]
 [PCTFREE  integer]
 [PCTUSED  integer]
 [INITRANS  integer]
 [MAXTRANS  integer]
 [STORAGE  storage-clause]
 [LOGGING | NOLOGGING]
 [CACHE | NOCACHE] ];

Schema:表的所有者
Table:表名
Column:字段名
Datatype:字段的数据类型
Tablespace:表所在的表空间
Pctfree:为了行长度增长而在每个块中保留的空间的量(以占整个空间减去块头部后所剩余空间的百分比形式表示),当剩余空间不足pctfree时,不再向该块中增加新行。
Pctused:在块剩余空间不足pctfree后,块已使用空间百分比必须小于pctused后,才能向该块中增加新行。
INITRANS:在块中预先分配的事务项数,缺省值为1
MAXTRANS:限定可以分配给每个块的最大事务项数,缺省值为255
STORAGE:标识决定如何将区分配给表的存储子句
LOGGING:指定表的创建将记录到重做日志文件中。它还指定所有针对该表的后续操作都将被记录下来。这是缺省设置。
NOLOGGING:指定表的创建将不被记录到重做日志文件中。
CACHE:指定即使在执行全表扫描时,为该表检索的块也将放置在缓冲区高速缓存的LRU列表最近使用的一端。
NOCACHE:指定在执行全表扫描时,为该表检索的块将放置在缓冲区高速缓存的LRU列表最近未使用的一端。
STORAGE子句:
INITIAL:初始区的大小
NEXT:下一个区的大小
PCTINCREASE:以后每个区空间增长的百分比
MINEXTENTS:段中初始区的数量
MAXEXTENTS:最大能扩展的区数

linux

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

How does Go language implement the addition, deletion, modification and query operations of the database? How does Go language implement the addition, deletion, modification and query operations of the database? Mar 27, 2024 pm 09:39 PM

Go language is an efficient, concise and easy-to-learn programming language. It is favored by developers because of its advantages in concurrent programming and network programming. In actual development, database operations are an indispensable part. This article will introduce how to use Go language to implement database addition, deletion, modification and query operations. In Go language, we usually use third-party libraries to operate databases, such as commonly used sql packages, gorm, etc. Here we take the sql package as an example to introduce how to implement the addition, deletion, modification and query operations of the database. Assume we are using a MySQL database.

Detailed tutorial on establishing a database connection using MySQLi in PHP Detailed tutorial on establishing a database connection using MySQLi in PHP Jun 04, 2024 pm 01:42 PM

How to use MySQLi to establish a database connection in PHP: Include MySQLi extension (require_once) Create connection function (functionconnect_to_db) Call connection function ($conn=connect_to_db()) Execute query ($result=$conn->query()) Close connection ( $conn->close())

How does Hibernate implement polymorphic mapping? How does Hibernate implement polymorphic mapping? Apr 17, 2024 pm 12:09 PM

Hibernate polymorphic mapping can map inherited classes to the database and provides the following mapping types: joined-subclass: Create a separate table for the subclass, including all columns of the parent class. table-per-class: Create a separate table for subclasses, containing only subclass-specific columns. union-subclass: similar to joined-subclass, but the parent class table unions all subclass columns.

iOS 18 adds a new 'Recovered' album function to retrieve lost or damaged photos iOS 18 adds a new 'Recovered' album function to retrieve lost or damaged photos Jul 18, 2024 am 05:48 AM

Apple's latest releases of iOS18, iPadOS18 and macOS Sequoia systems have added an important feature to the Photos application, designed to help users easily recover photos and videos lost or damaged due to various reasons. The new feature introduces an album called "Recovered" in the Tools section of the Photos app that will automatically appear when a user has pictures or videos on their device that are not part of their photo library. The emergence of the "Recovered" album provides a solution for photos and videos lost due to database corruption, the camera application not saving to the photo library correctly, or a third-party application managing the photo library. Users only need a few simple steps

An in-depth analysis of how HTML reads the database An in-depth analysis of how HTML reads the database Apr 09, 2024 pm 12:36 PM

HTML cannot read the database directly, but it can be achieved through JavaScript and AJAX. The steps include establishing a database connection, sending a query, processing the response, and updating the page. This article provides a practical example of using JavaScript, AJAX and PHP to read data from a MySQL database, showing how to dynamically display query results in an HTML page. This example uses XMLHttpRequest to establish a database connection, send a query and process the response, thereby filling data into page elements and realizing the function of HTML reading the database.

Analysis of the basic principles of MySQL database management system Analysis of the basic principles of MySQL database management system Mar 25, 2024 pm 12:42 PM

Analysis of the basic principles of the MySQL database management system MySQL is a commonly used relational database management system that uses structured query language (SQL) for data storage and management. This article will introduce the basic principles of the MySQL database management system, including database creation, data table design, data addition, deletion, modification, and other operations, and provide specific code examples. 1. Database Creation In MySQL, you first need to create a database instance to store data. The following code can create a file named "my

Tips and practices for handling Chinese garbled characters in databases with PHP Tips and practices for handling Chinese garbled characters in databases with PHP Mar 27, 2024 pm 05:21 PM

PHP is a back-end programming language widely used in website development. It has powerful database operation functions and is often used to interact with databases such as MySQL. However, due to the complexity of Chinese character encoding, problems often arise when dealing with Chinese garbled characters in the database. This article will introduce the skills and practices of PHP in handling Chinese garbled characters in databases, including common causes of garbled characters, solutions and specific code examples. Common reasons for garbled characters are incorrect database character set settings: the correct character set needs to be selected when creating the database, such as utf8 or u

How to handle database connection errors in PHP How to handle database connection errors in PHP Jun 05, 2024 pm 02:16 PM

To handle database connection errors in PHP, you can use the following steps: Use mysqli_connect_errno() to obtain the error code. Use mysqli_connect_error() to get the error message. By capturing and logging these error messages, database connection issues can be easily identified and resolved, ensuring the smooth running of your application.

See all articles