1.下载连接mysql所需要的jar包,下载之后解压
传送门
2.将jar包添加到该项目的库中
3.编写代码
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`user_name` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL COMMENT '用户名',
`age` int(11) COMMENT '年龄',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;
SET FOREIGN_KEY_CHECKS = 1;
import com.mysql.jdbc.Connection;
import com.mysql.jdbc.Statement;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class JDBC {
public static void query() {
try {
/**
将mysql驱动注册到DriverManager中去
将"com.mysql.jdbc.Driver" 当做参数传入,就是告诉JVM,去"com.mysql.jdbc"这个路径下找Driver类,将其加载到内存中。
*/
//加载数据库驱动
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/test?useSSL=false";
String user = "root";
String password = "xxx";
//建立和数据库的连接,并返回表示连接的Connection对象
Connection connection = (Connection) DriverManager.getConnection(url, user, password);
//要执行SQL语句,必须获得java.sql.Statement实例
Statement Statement = (com.mysql.jdbc.Statement) connection.createStatement();
String sql = "select * from user";
//ResultSet包含符合SQL语句中条件的所有行,并且它通过一套get方法提供了对这些行中数据的访问
ResultSet resultSet = Statement.executeQuery(sql);
while (resultSet.next()) {
String name = resultSet.getString("user_name");
String age = resultSet.getString("age");
System.out.println(name + " " + age);
}
//
/**
* 操作完成以后要把所有使用的JDBC对象全都关闭,以释放JDBC资源
* 先关闭requestSet
* 再关闭preparedStatement
* 最后关闭连接对象connection
*/
//关闭结果集
resultSet.close();
//关闭执行方法
Statement.close();
//关闭连接
connection.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void insert() {
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/test?useSSL=false";
String user = "root";
String password = "xxx";
Connection connection = (Connection) DriverManager.getConnection(url, user, password);
/**
*
* 使用Statement需要进行拼写SQl语句,辛苦并且容易出错,使用PreparedStatement可以传入带占位符的SQL语句(使用?进行占位)
*/
String sql = "insert into user(user_name,age) values (?,?)";
PreparedStatement preparedStatement = connection.prepareStatement(sql);
//注意:该处索引从1开始,而不是0
preparedStatement.setString(1, "lisi");
preparedStatement.setInt(2, 22);
int result = preparedStatement.executeUpdate();
System.out.println(result);
preparedStatement.close();
connection.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void update() {
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/test?useSSL=false";
String user = "root";
String password = "xxx";
Connection connection = (Connection) DriverManager.getConnection(url, user, password);
String sql = "update user set user_name=?,age=? where id=?";
PreparedStatement preparedStatement = connection.prepareStatement(sql);
preparedStatement.setString(1, "xiaowang");
preparedStatement.setInt(2, 13);
preparedStatement.setInt(3, 2);
int result = preparedStatement.executeUpdate();
System.out.println(result);
preparedStatement.close();
connection.close();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void delete() {
try {
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/test?useSSL=false";
String user = "root";
String password = "xxx";
Connection connection = (Connection) DriverManager.getConnection(url, user, password);
String sql = "delete from user where id=?";
PreparedStatement preparedStatement = connection.prepareStatement(sql);
preparedStatement.setInt(1, 2);
int result = preparedStatement.executeUpdate();
System.out.println(result);
preparedStatement.close();
connection.close();
} catch (Exception e) {
e.printStackTrace();
}
}
}
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