How to create a database table
In the database, you can use the "CREATE TABLE" statement to create a table. The syntax format is "CREATE TABLE table name (column name 1 data type (maximum length) 1 [,...] column name n data type ( Maximum length)n);".
The operating environment of this tutorial: windows7 system, mysql8 version, Dell G3 computer.
Creation of tables in database
The process of creating a data table is the process of specifying the attributes of the data columns, and it is also the process of implementing data integrity (including entity integrity, reference integrity and domain integrity) constraints.
Basic syntax
In MySQL, you can use the CREATE TABLE statement to create a table. The syntax format is:
CREATE TABLE <表名> ([表定义选项]);
Among them, the format of [table definition option] is:
<列名1> <数据类型(size)1> [,…] <列名n> <数据类型(size)n>
The main syntax and usage instructions of the CREATE TABLE statement are as follows:
CREATE TABLE: For creating a table with a given name, you must have table CREATE permissions.
: Specifies the name of the table to be created, given after CREATE TABLE, and must comply with the identifier naming rules. The table name is specified as db_name.tbl_name to create the table in a specific database. It can be created this way regardless of whether there is a current database. db-name can be omitted when creating a table in the current database. If you use quoted distinguished names, the database and table names should be quoted separately. For example, 'mydb'.'mytbl' is legal, but 'mydb.mytbl' is not.
: Table creation definition, consisting of column name (col_name), column definition (column_definition), and possible null value specifications, integrity constraints, or table indexes composition.
size: Specifies the maximum length of columns in the table.
By default, the table is created in the current database. If the table already exists, there is no current database, or the database does not exist, an error will occur.
Tip: When using CREATE TABLE to create a table, you must specify the following information:
The name of the table to be created is not case-sensitive, and keys in the SQL language cannot be used. words, such as DROP, ALTER, INSERT, etc.
The name and data type of each column (field) in the data table. If you create multiple columns, separate them with commas.
Example:
Select the database test_db to create the table
mysql> USE test_db; Database changed
Copy after loginCreate the tb_emp1 data table
mysql> CREATE TABLE tb_emp1 -> ( -> id INT(11), -> name VARCHAR(25), -> deptId INT(11), -> salary FLOAT -> ); Query OK, 0 rows affected (0.37 sec)Copy after loginUse SHOW TABLES statement to check whether the data table is created successfully
mysql> SHOW TABLES; +--------------------+ | Tables_in_test_db | +--------------------+ | tb_emp1 | +--------------------+ 1 rows in set (0.00 sec)
Copy after loginRelated free learning recommendations: mysql video tutorial
The above is the detailed content of How to create a database table. For more information, please follow other related articles on the PHP Chinese website!
Statement of this WebsiteThe 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
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
AI Hentai Generator
Generate AI Hentai for free.
Hot Article
R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌R.E.P.O. Best Graphic Settings3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌Assassin's Creed Shadows: Seashell Riddle Solution1 weeks ago By DDDR.E.P.O. How to Fix Audio if You Can't Hear Anyone3 weeks ago By 尊渡假赌尊渡假赌尊渡假赌Where to find the Crane Control Keycard in Atomfall1 weeks ago By DDD
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
CakePHP Tutorial
1359
52
See all articles
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.
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
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
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.
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 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.
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
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
