Parsing MySQL data types: Explore the characteristics and applications of different basic data types

Detailed explanation of MySQL data types: Explore the characteristics and uses of various basic data types

Introduction:
In database applications, the storage and processing of data are very important. As a popular open source relational database management system, MySQL provides a variety of data types to meet different data storage needs. This article will delve into various basic data types of MySQL, including integers, floating point, date and time, string and binary data, etc. And provide specific code examples to help readers better understand and apply these data types.

1. Integer type (Integer)
Literally, the integer type is a data type used to represent integers. MySQL provides multiple integer data types, including TINYINT, SMALLINT, INT, BIGINT, etc. Different integer data types have different storage ranges and sizes.
The following is sample code for some common integer data types and their uses:

1. TINYINT
   TINYINT is suitable for storing small integers, ranging from -128 to 127 (signed) or 0 to 255 (unsigned). For example, TINYINT can be used to represent a person's age.

CREATE TABLE persons (

id INT AUTO_INCREMENT PRIMARY KEY,
age TINYINT

);

2. INT
   INT is the most commonly used integer data type and is suitable for storing normal size An integer ranging from -2147483648 to 2147483647 (signed) or 0 to 4294967295 (unsigned). For example, INT can be used to represent the price of a product.

CREATE TABLE products (

id INT AUTO_INCREMENT PRIMARY KEY,
price INT

);

3. BIGINT
   BIGINT is suitable for storing very large integers, ranging from -9223372036854775808 to 9223372036854775807 (signed) or 0 to 18446744073709551615 (unsigned). For example, BIGINT can be used to represent the balance of an account.

CREATE TABLE accounts (

id INT AUTO_INCREMENT PRIMARY KEY,
balance BIGINT

);

2. Floating-Point type (Floating-Point)
Floating-point type is used to store decimals, there are Two common floating-point data types: FLOAT and DOUBLE. Different floating-point data types have different storage precision and range. The following is the specific sample code:

1. FLOAT
   FLOAT is suitable for storing single-precision floating point numbers, the range is -3.402823466E 38 to -1.175494351E-38, 0, 1.175494351E-38 to 3.402823466 E38. For example, you can use FLOAT to represent the radius of a circle.

CREATE TABLE circles (

id INT AUTO_INCREMENT PRIMARY KEY,
radius FLOAT

);

2. DOUBLE
   DOUBLE is suitable for storing double-precision floating point numbers, the range is -1.7976931348623157E 308 to -2.2250738585072014E-308, 0, 2.2250738585072014E-308 to 1.7976931348623157E 308. For example, you can use DOUBLE to represent the area of ​​a triangle.

CREATE TABLE triangles (

id INT AUTO_INCREMENT PRIMARY KEY,
area DOUBLE

);

3. Date and Time (Date and Time)
MySQL provides a variety of date and time related Data types, including DATE, TIME, DATETIME, TIMESTAMP, etc. The following is the specific sample code:

1. DATE
   DATE is used to store dates in the format YYYY-MM-DD. For example, you can use DATE to record the date of an order.

CREATE TABLE orders (

id INT AUTO_INCREMENT PRIMARY KEY,
order_date DATE

);

2. TIME
   TIME is used to store time in the format of HH:MM:SS. For example, you can use TIME to record a user's login time.

CREATE TABLE users (

id INT AUTO_INCREMENT PRIMARY KEY,
login_time TIME

);

3. DATETIME
   DATETIME is used to store date and time in the format YYYY-MM-DD HH:MM:SS. For example, you can use DATETIME to record the publication time of an article.

CREATE TABLE articles (

id INT AUTO_INCREMENT PRIMARY KEY,
publish_datetime DATETIME

);

4. TIMESTAMP
   TIMESTAMP is used to store date and time and automatically updated every time Record the time of last modification. For example, you can use TIMESTAMP to record a user's last login time.

CREATE TABLE users (

id INT AUTO_INCREMENT PRIMARY KEY,
last_login TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP

);

4. String (String)
The string data type is used to store characters and text. MySQL provides multiple string data types, including CHAR, VARCHAR, TEXT, ENUM, etc. The following is the specific sample code:

1. CHAR
   CHAR is used to store fixed-length strings and can store up to 255 characters. For example, CHAR can be used to store a person's gender.

CREATE TABLE persons (

id INT AUTO_INCREMENT PRIMARY KEY,
gender CHAR(1)

);

2. VARCHAR
   VARCHAR is used to store variable length strings and can store up to 65535 characters. For example, you can use VARCHAR to store a person's name.

CREATE TABLE persons (

id INT AUTO_INCREMENT PRIMARY KEY,
name VARCHAR(50)

);

3. TEXT
   TEXT is used to store large amounts of text data, with a maximum storage capacity of 65535 characters . For example, TEXT can be used to store the content of an article.

CREATE TABLE articles (

id INT AUTO_INCREMENT PRIMARY KEY,
content TEXT

);

4. ENUM
   ENUM is used to store enumeration values, that is, a limited set of values. For example, you can use ENUM to store a person's marital status.

CREATE TABLE persons (

id INT AUTO_INCREMENT PRIMARY KEY,
marital_status ENUM('单身', '已婚', '离异', '丧偶')

);

5. Binary Data (Binary Data)
Binary data type is used to store binary files, such as images , audio, video, etc. MySQL provides multiple binary data types, such as BINARY, VARBINARY, and BLOB. The following is the specific sample code:

1. BINARY
   BINARY用于存储固定长度的二进制数据，最多可以存储255个字节。例如，可以用BINARY来存储一个图像的二进制数据。

CREATE TABLE images (

id INT AUTO_INCREMENT PRIMARY KEY,
data BINARY(255)

);

2. VARBINARY
   VARBINARY用于存储可变长度的二进制数据，最多可以存储65535个字节。例如，可以用VARBINARY来存储一个音频的二进制数据。

CREATE TABLE audios (

id INT AUTO_INCREMENT PRIMARY KEY,
data VARBINARY(65535)

);

3. BLOB
   BLOB用于存储大量二进制数据，最大存储容量为65535个字节。例如，可以用BLOB来存储一个视频的二进制数据。

CREATE TABLE videos (

id INT AUTO_INCREMENT PRIMARY KEY,
data BLOB

);

结论：
MySQL提供了多种基本数据类型来满足不同的存储需求。本文详细探讨了整型、浮点型、日期与时间、字符串和二进制数据等数据类型的特点和用途，并提供了具体的代码示例。读者在实际的数据库应用程序中可以根据需求选择适当的数据类型，以确保数据的准确性和高效性。同时，本文只对MySQL的基本数据类型进行了介绍，读者还可以深入研究MySQL的高级数据类型和自定义数据类型，以更好地应对更复杂的数据存储和处理需求。

The above is the detailed content of Parsing MySQL data types: Explore the characteristics and applications of different basic data types. For more information, please follow other related articles on the PHP Chinese website!