MySQL数据库中sql表设计的注意事项

-- 示例：创建一个学生信息表
CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50),
    LastName VARCHAR(50),
    Age INT
);

-- 示例：选择适当的数据类型
CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50),
    LastName VARCHAR(50),
    Age INT
);

-- 示例：添加唯一性约束
CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    Email VARCHAR(100) UNIQUE,
    FirstName VARCHAR(50),
    LastName VARCHAR(50)
);

-- 示例：指定主键
CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50),
    LastName VARCHAR(50)
);

-- 示例：添加外键关联
CREATE TABLE Grades (
    GradeID INT PRIMARY KEY,
    StudentID INT,
    Grade DECIMAL(3, 2),
    FOREIGN KEY (StudentID) REFERENCES Students(StudentID)
);

-- 示例：创建索引
CREATE INDEX idx_student_lastname ON Students(LastName);

-- 示例：添加约束条件
CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50) NOT NULL,
    LastName VARCHAR(50) NOT NULL
);

-- 示例：拆分规范化的表
CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50),
    LastName VARCHAR(50)
);

CREATE TABLE Courses (
    CourseID INT PRIMARY KEY,
    CourseName VARCHAR(100)
);

-- 示例：反规范化
ALTER TABLE Students
ADD COLUMN AverageGrade DECIMAL(3, 2);

-- 示例：使用清晰的字段名
CREATE TABLE Students (
    Student_ID INT PRIMARY KEY,
    First_Name VARCHAR(50),
    Last_Name VARCHAR(50)
);

-- 示例：命名规范的表
CREATE TABLE student_info(
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50),
    LastName VARCHAR(50)
);

-- 示例：设置默认值
CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50),
    LastName VARCHAR(50),
    EnrollmentDate DATE DEFAULT CURRENT_DATE
);

-- 示例：分区设计
CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50),
    LastName VARCHAR(50)
)
PARTITION BY RANGE (StudentID) (
    PARTITION p0 VALUES LESS THAN (1000),
    PARTITION p1 VALUES LESS THAN (2000),
    PARTITION p2 VALUES LESS THAN MAXVALUE
);

-- 示例：审计跟踪
CREATE TABLE Students (
    StudentID INT PRIMARY KEY,
    FirstName VARCHAR(50),
    LastName VARCHAR(50),
    CreatedAt TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    UpdatedAt TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);

-- 示例：创建索引以优化性能
CREATE INDEX idx_lastname ON Students(LastName);

-- 示例：限制对敏感数据的访问
GRANT SELECT ON Students TO 'public';

-- 示例：备份数据库
BACKUP DATABASE MyDatabase TO 'backup_path';

-- 示例：文档化表结构
COMMENT ON TABLE Students IS 'This table stores information about students.';
COMMENT ON COLUMN Students.FirstName IS 'First name of the student.';