首次登录MySQL数据库
1. 运行 -> cmd, xxxx 为root密码：
mysql -uroot -pxxxx
2. 创建新用户，例如创建用户 scott，密码 tiger
create user 'scott'@'localhost' identified by 'tiger';
同时赋予权限
grant select, insert, update, delete, create, create view, drop, execute, references on *.* to 'scott'@'localhost';
之后可以用新的帐号连接到MySQL
mysql -uscott -ptiger
如果允许任意IP使用该帐号：
grant all privileges on *.* to 'scott'@'%' identified by 'tiger'; （但MySQL 8 这条指令报错....）
MySQL数据库操作
1. 创建数据库
create database dbName;
2. 删除数据库
drop dbName;
3. 查看存在的所有数据库
show databases;
4. 切换到另一个数据库：
use dbName;
5. 查看当前数据库中存在的所有表
show tables;
表操作
1. 创建表举例：
创建表Course并增加记录
create table Course (
courseId char(5),
subjectId char(4) not null,
courseNumber integer,
title varchar(50) not null,
numOfCredits integer,
primary key (courseId)
);
insert into Course(courseId, subjectId, courseNumber, title, numOfCredits)values('11111', 'CSCI', '1301', 'Introduction to Java I', 3);
insert into Course(courseId, subjectId, courseNumber, title, numOfCredits)values('11112', 'CSCI', '1302', 'Introduction to Java II', 3);
insert into Course(courseId, subjectId, courseNumber, title, numOfCredits)values('11113', 'CSCI', '3720', 'Database Systems', 3);
insert into Course(courseId, subjectId, courseNumber, title, numOfCredits)values('11114', 'CSCI', '4750', 'Rapid Java Application', 3);
insert into Course(courseId, subjectId, courseNumber, title, numOfCredits)values('11115', 'MATH', '2750', 'Calculus I', 3);
insert into Course(courseId, subjectId, courseNumber, title, numOfCredits)values('11116', 'MATH', '3750', 'Calculus II', 3);
insert into Course(courseId, subjectId, courseNumber, title, numOfCredits)values('11117', 'EDUC', '1111', 'Reading', 3);
insert into Course(courseId, subjectId, courseNumber, title, numOfCredits)values('11118', 'ITEC', '1344', 'Database Administration', 3);
创建表student并增加记录
create table Student (
ssn char(9),
firstName varchar(25),
mi char(1),
lastName varchar(25),
phone char(11),
birthDate date,
street varchar(25),
zipCode char(5),
deptId char(4),
primary key (ssn)
);
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111110', 'Jacob', 'R', 'Smith', '9129219434', 19850409, '99 Kingston Street', '31435', 'BIOL');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111111', 'John', 'R', 'Stevenson','9129219434', null, '100 Main St.', '31435', 'BIOL');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111112', 'George', 'R', 'Smith', '9129213454', 19741010, '1200 Abercorn Street', '31435', 'CS');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111113', 'Frank', 'R', 'Jones', '9125919434', 19700909, '100 Main Street', '31435', 'BIOL');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111114', 'Jean', 'R', 'Smith', '9129219434', 19700209, '100 Main Street', '31435', 'CHEM');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111115', 'Josh', 'R', 'Woo', '7075989434', 19700209, '555 Franklin St.', '31435', 'CHEM');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111116', 'Josh', 'R', 'Smith', '9129219434', 19730209, '100 Main Street', '31435', 'BIOL');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111117', 'Joy', 'R', 'Kennedy', '9129229434', 19740309, '103 Bay Street', '31435', 'CS');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111118', 'Toni', 'R', 'Peterson', '9129229434', 19640429, '103 Bay Street', '31435', 'MATH');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111119', 'Patrick','R', 'Stoneman', '9129229434', 19690429, '101 Washington St.', '31435', 'MATH');
insert into student (ssn, firstName, mi, lastName, phone, birthDate, street, zipCode, deptId)
values ('444111120', 'Rick', 'R', 'Carter', '9125919434', 19860409, '19 West Ford St.', '31435', 'BIOL');
创建表Enrollment并增加记录
create table Enrollment (
ssn char(9),
courseId char(5),
dateRegistered date,
grade char(1),
primary key (ssn, courseId),
foreign key (ssn) references
Student(ssn),
foreign key (courseId) references
Course(courseId)
);
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111110', '11111', 20040319, 'A');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111110', '11112', 20040319, 'B');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111110', '11113', 20040319, 'C');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111111', '11111', 20040319, 'D');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111111', '11112', 20040319, 'F');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111111', '11113', 20040319, 'A');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111112', '11114', 20040319, 'B');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111112', '11115', 20040319, 'C');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111112', '11116', 20040319, 'D');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111113', '11111', 20040319, 'A');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111113', '11113', 20040319, 'A');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111114', '11115', 20040319, 'B');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111115', '11115', 20040319, 'F');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111115', '11116', 20040319, 'F');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111116', '11111', 20040319, 'D');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111117', '11111', 20040319, 'D');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111118', '11111', 20040319, 'A');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111118', '11112', 20040319, 'D');
insert into Enrollment(ssn, courseId, dateRegistered, grade)
values('444111118', '11113', 20040319, 'B');
由于MySQL命令写错了就要重写一遍，把命令写到一个脚本里再执行效率比较高：
source scriptName.sql
以上3段指令，可以分别写到3个sql脚本里再执行。
2. 删除表
drop table tableName;
3. 在表中插入一条记录
insert into tableName [(column1, column2, ..., column)] values (value1, value2, ..., valuen);
例如在数据库表Course中插入一条记录
insert into Course (courseId, subjectId, courseNumber, title, numOfCredits)values ('11113', 'CSCI', '3720', 'Database Systems', 3);
4. 在表中删除记录
delete from tableName [where condition];
5. 清空表的所有记录
delete from tableName;
6. 简单查询命令
select column-list from table-list [where condition];
例如：查找CS系所有学生：
select firstName, mi, lastName from Student where deptId = 'CS';
查询结果：
NetBeans: 使用 JDBC driver 连接 MySQL 数据库
首先，到MySQL网站下载 mysql-connector-java-8.0.11.zip，并解压：
然后在NetBean项目右键选属性, 选 ”添加 JAR/文件夹(F)“选择mysql-connector-java-8.0.11.jar,
JDBC 连 MySQL 的 code 如下：
package simplejdbc;
import java.sql.*;
/**
*
* @author alicewang
*/
public class SimpleJDBC {
/**
* @param args the command line arguments
*/
public static void main(String[] args) throws SQLException, ClassNotFoundException {
System.out.println("-------- MySQL JDBC Connection Testing ------------");
try {
Class.forName("com.mysql.cj.jdbc.Driver");
} catch (ClassNotFoundException e) {
System.out.println("Where is your MySQL JDBC Driver?");
//e.printStackTrace();
return;
}
System.out.println("MySQL JDBC Driver Registered!");
Connection connection = null;
try {
connection = DriverManager.getConnection("jdbc:mysql://localhost/javabook?serverTimezone=GMT&useSSL=false" , "scott", "tiger");
} catch (SQLException e) {
System.out.println("Connection Failed! Check output console");
//e.printStackTrace();
return;
}
if (connection != null) {
System.out.println("You made it, take control your database now!");
} else {
System.out.println("Failed to make connection!");
}
}
}
输出结果：
-------- MySQL JDBC Connection Testing ------------ MySQL JDBC Driver Registered! You made it, take control your database now!
如果在 jdbc:mysql://localhost/javabook 后面不加 serverTimezone=GMT 和 useSSL = false，要么出现异常，要么出现警告。
Class.forName("com.mysql.jdbc.Driver"); 根据编译提示改为：
Class.forName("com.mysql.cj.jdbc.Driver");
Introduction to Java Programming 10th Chapter 32.
Connect to MySQL with JDBC driver
Connecting to MySQL Using JDBC Driver
Introduction to Java Programming 10th Chapter 32.
Connect to MySQL with JDBC driver
Connecting to MySQL Using JDBC Driver