JDBC | 第一章: 快速开始使用JDBC连接Mysql数据库?
开始使用基于java的JDBC技术来连接mysql进行msyql数据库简单的CRUD操作
下载对应mysql驱动包
这里我创建maven项目基于maven下载
<!--mysql 驱动-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.21</version>
</dependency>
<!---->
连接数据库
/*
* jdbc:mysql: 是指JDBC连接方式；
*127.0.0.1: 是指你的本机地址；
* 3306 SQL数据库的端口号；
* mysql 就是你要连接的数据库的名字。
* characterEncoding 指定数据库连接的编码方式
* com.mysql.jdbc.Driver 注册数据库驱动 过时
* com.mysql.cj.jdbc.Driver 新的数据库驱动
*/
public Connection getConnection() {
//mysql 连接url
String url = "jdbc:mysql://localhost:3306/kenx_test?characterEncoding=utf-8";
//数据库用户名
String userName = "root";
//数据库密码
String passWord = "root";
try {
Class.forName("com.mysql.cj.jdbc.Driver"); //注册数据库驱动
Connection conn = DriverManager.getConnection(url, userName, passWord); //获取数据连接
System.out.println("数据库连接成功");
return conn;
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
进行数据添加操作
public int ins() {
Connection connection = null;
Statement statement = null;
String sql = "";
try {
//获取数据连接
connection = getConnection();
//获取发送sql指令执行sql对象
statement = connection.createStatement();
StringBuffer sbf = new StringBuffer("insert into user (id, name, age, email, manager_id, create_time)");
String id = String.valueOf(System.currentTimeMillis());
Timestamp dateTime = Timestamp.valueOf(DateUtil.now());
sbf.append(" values (" + id + ",'kenx',24,'[email protected]',155065178165505,'" + dateTime + "')");
sql = sbf.toString();
System.out.println("执行sql" + sql);
//执行成功返回1
int success = statement.executeUpdate(sql);
return success;
} catch (Exception e) {
e.printStackTrace();
return 0;
}finally {
//执行完数据库操作后记得关闭数据库连接资源
try{
statement.close();
connection.close();
}catch (SQLException e){
e.printStackTrace();
}
}
}
进行数据库的查询操作
public void select() {
Connection connection = null;
Statement statement = null;
ResultSet rs = null;
String sql = "select * from user limit 0,1";
try {
//获取数据连接
connection = getConnection();
//获取发送sql指令执行sql对象
statement = connection.createStatement();
//返回查询结果集用于保存数据库查询内容
rs = statement.executeQuery(sql);
//遍历结果集拿到数据
while (rs.next()) {
System.out.println("id" + "\t" + rs.getString("id"));
System.out.println("name" + "\t" + rs.getString("name"));
System.out.println("age" + "\t" + rs.getString("age"));
System.out.println("email" + "\t" + rs.getString("email"));
System.out.println("manager_id" + "\t" + rs.getString("manager_id"));
System.out.println("create_time" + "\t" + rs.getString("create_time"));
}
} catch (Exception e) {
e.printStackTrace();
}finally {
//执行完数据库操作后记得关闭数据库连接资源
try{
rs.close();
statement.close();
connection.close();
}catch (SQLException e){
e.printStackTrace();
}
}
}
进行数据库更新操作
public int update() {
Connection connection = null;
Statement statement = null;
String sql = "update user\n" +
"set manager_id =155065512602445\n" +
"where id=1597890374878";
try {
//获取数据连接
connection = getConnection();
//获取发送sql指令执行sql对象
statement = connection.createStatement();
//更新成功返回1
int success = statement.executeUpdate(sql);
return success;
} catch (Exception e) {
e.printStackTrace();
return 0;
}finally {
//执行完数据库操作后记得关闭数据库连接资源
try{
statement.close();
connection.close();
}catch (SQLException e){
e.printStackTrace();
}
}
}
进行数据库删除操作
public int del(){
Connection connection = null;
Statement statement = null;
String sql = "delete from user where id='1597890374878'";
try {
//获取数据连接
connection = getConnection();
//获取发送sql指令执行sql对象
statement = connection.createStatement();
//删除成功返回1
int success = statement.executeUpdate(sql);
return success;
} catch (Exception e) {
e.printStackTrace();
return 0;
}finally {
//执行完数据库操作后记得关闭数据库连接资源
try{
statement.close();
connection.close();
}catch (SQLException e){
e.printStackTrace();
}
}
}
完整项目案例
点击这里 github
