Home Database Mysql Tutorial SQL语言操作数据表

SQL语言操作数据表

Jun 07, 2016 pm 05:44 PM
operate data sheet language

---检查数据库是否存在 use master go if exists(select * from sysdatabases where) drop database studentdb ----创建数据库 Create database studentdb on primary ( name='sudent', filename='d:\data\student.mdf', size=10, maxsize=50, filegrowth=3

---检查数据库是否存在

use master

go

if exists(select * from sysdatabases where)

 drop database studentdb

----创建数据库

Create database studentdb

on primary (

 name='sudent',

 filename='d:\data\student.mdf',  

size=10,

maxsize=50,  

filegrowth=3

)

log on (

 name='student-log',

 filename='d:\data\student-log.ldf',

 size=15,

 filegrowth=15%

)

---创建第一张表

use studentdb

go

if exists (select * from sysobjects where)  

drop table t_student

create table t_student

(

 sno char(3) not null,  

sname char(20) null,  

sdenger char(2) not null,

 sbirth datetime null,

 sclass varchar(20) not null

)

---创建第二张表

use studentdb

go

if exists (select * from sysobjects where)  

drop table t_course

create table t_course

 cno char(3) not null,

 cname char(20) null  

)

--创建第三张表

use studentdb go

if exists (select * from sysobjects where)

 drop table t_score

create table t_score

(

 sno char(3) not null,

 cno char(3) not null,

 score int not null  

)

--修改列

alter table t_student

alter column sno char(12)

--增加列

alter table t_student

add sfavorate char(30)

--删除列

alter table t_student

drop column sfavorate

--查看表

sp_help t_student

--删除表

drop table t_student

,香港服务器,美国空间,香港虚拟主机
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

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

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)

PyCharm usage tutorial: guide you in detail to run the operation PyCharm usage tutorial: guide you in detail to run the operation Feb 26, 2024 pm 05:51 PM

PyCharm is a very popular Python integrated development environment (IDE). It provides a wealth of functions and tools to make Python development more efficient and convenient. This article will introduce you to the basic operation methods of PyCharm and provide specific code examples to help readers quickly get started and become proficient in operating the tool. 1. Download and install PyCharm First, we need to go to the PyCharm official website (https://www.jetbrains.com/pyc

What is sudo and why is it important? What is sudo and why is it important? Feb 21, 2024 pm 07:01 PM

sudo (superuser execution) is a key command in Linux and Unix systems that allows ordinary users to run specific commands with root privileges. The function of sudo is mainly reflected in the following aspects: Providing permission control: sudo achieves strict control over system resources and sensitive operations by authorizing users to temporarily obtain superuser permissions. Ordinary users can only obtain temporary privileges through sudo when needed, and do not need to log in as superuser all the time. Improved security: By using sudo, you can avoid using the root account during routine operations. Using the root account for all operations may lead to unexpected system damage, as any mistaken or careless operation will have full permissions. and

Linux Deploy operation steps and precautions Linux Deploy operation steps and precautions Mar 14, 2024 pm 03:03 PM

LinuxDeploy operating steps and precautions LinuxDeploy is a powerful tool that can help users quickly deploy various Linux distributions on Android devices, allowing users to experience a complete Linux system on their mobile devices. This article will introduce the operating steps and precautions of LinuxDeploy in detail, and provide specific code examples to help readers better use this tool. Operation steps: Install LinuxDeploy: First, install

What to do if you forget to press F2 for win10 boot password What to do if you forget to press F2 for win10 boot password Feb 28, 2024 am 08:31 AM

Presumably many users have several unused computers at home, and they have completely forgotten the power-on password because they have not been used for a long time, so they would like to know what to do if they forget the password? Then let’s take a look together. What to do if you forget to press F2 for win10 boot password? 1. Press the power button of the computer, and then press F2 when turning on the computer (different computer brands have different buttons to enter the BIOS). 2. In the bios interface, find the security option (the location may be different for different brands of computers). Usually in the settings menu at the top. 3. Then find the SupervisorPassword option and click it. 4. At this time, the user can see his password, and at the same time find the Enabled next to it and switch it to Dis.

Huawei Mate60 Pro screenshot operation steps sharing Huawei Mate60 Pro screenshot operation steps sharing Mar 23, 2024 am 11:15 AM

With the popularity of smartphones, the screenshot function has become one of the essential skills for daily use of mobile phones. As one of Huawei's flagship mobile phones, Huawei Mate60Pro's screenshot function has naturally attracted much attention from users. Today, we will share the screenshot operation steps of Huawei Mate60Pro mobile phone, so that everyone can take screenshots more conveniently. First of all, Huawei Mate60Pro mobile phone provides a variety of screenshot methods, and you can choose the method that suits you according to your personal habits. The following is a detailed introduction to several commonly used interceptions:

PHP PDO Tutorial: An Advanced Guide from Basics to Mastery PHP PDO Tutorial: An Advanced Guide from Basics to Mastery Feb 19, 2024 pm 06:30 PM

1. Introduction to PDO PDO is an extension library of PHP, which provides an object-oriented way to operate the database. PDO supports a variety of databases, including Mysql, postgresql, oracle, SQLServer, etc. PDO enables developers to use a unified API to operate different databases, which allows developers to easily switch between different databases. 2. PDO connects to the database. To use PDO to connect to the database, you first need to create a PDO object. The constructor of the PDO object receives three parameters: database type, host name, database username and password. For example, the following code creates an object that connects to a mysql database: $dsn="mysq

Exploring the boundaries of agents: AgentQuest, a modular benchmark framework for comprehensively measuring and improving the performance of large language model agents Exploring the boundaries of agents: AgentQuest, a modular benchmark framework for comprehensively measuring and improving the performance of large language model agents Apr 11, 2024 pm 08:52 PM

Based on the continuous optimization of large models, LLM agents - these powerful algorithmic entities have shown the potential to solve complex multi-step reasoning tasks. From natural language processing to deep learning, LLM agents are gradually becoming the focus of research and industry. They can not only understand and generate human language, but also formulate strategies, perform tasks in diverse environments, and even use API calls and coding to Build solutions. In this context, the introduction of the AgentQuest framework is a milestone. It not only provides a modular benchmarking platform for the evaluation and advancement of LLM agents, but also provides researchers with a Powerful tools to track and improve the performance of these agents at a more granular level

How to change the language display of vivox60pro vivox60pro system language setting method How to change the language display of vivox60pro vivox60pro system language setting method Mar 23, 2024 am 09:06 AM

1. Click [System Management] in the phone settings menu. 2. Click the [Language] option. 3. Select the system language you want to use.

See all articles