0.引入驱动jar包
使用jdbc进行具体操作前,需要引入相关数据库的jar包, 或者使用mave管理依赖
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.23</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.xerial/sqlite-jdbc -->
<dependency>
<groupId>org.xerial</groupId>
<artifactId>sqlite-jdbc</artifactId>
<version>3.34.0</version>
</dependency>
1.加载驱动
Class.forName(DRIVER);
2.获取数据库连接对象
Connection conn=DriverManager.getConnection(URL);
3.创建(预处理)语句对象
普通语句对象
Statement stmt=conn.createStatement();
预处理语句对象
PreparedStatement pstmt=conn.prepareStatement(sql);
pstmt.setXxx(int parameterIndex, Xxx x); // 参数索引从1开始
4.执行sql语句
普通语句对象执行sql
boolean b=stmt.execute(sql);
int i=stmt.executeUpdate(sql);
ResultSet resultSet=stmt.executeQuery(sql);
预处理语句对象执行sql
int i=pstmt.executeUpdate();
ResultSet resultSet=pstmt.executeQuery();
5.处理结果集
while(resultSet.next())
{
int id=resultSet.getInt("id");
String name=resultSet.getString("name");
}
6.关闭结果集,语句,连接
resultSet.close();
stmt.close();
conn.close();
jdbc工具类封装
在类路径下创建配置文件
mysql.properties
DRIVER=com.mysql.cj.jdbc.Driver
URL=jdbc:mysql://localhost:3306/test
USER=root
PASSWORD=root
DBUtil.java
public class DBUtil
{
private static final String URL;
private static final String USER;
private static final String PASSWORD;
private DBUtil(){}
static
{
// 从properties文件中加载配置信息
ResourceBundle bundle=ResourceBundle.getBundle("mysql");
String DRIVER=bundle.getString("DRIVER");
URL=bundle.getString("URL");
USER=bundle.getString("USER");
PASSWORD=bundle.getString("PASSWORD");
try
{
Class.forName(DRIVER);
}
catch(ClassNotFoundException e)
{
e.printStackTrace();
}
}
public static Connection getConnection() throws SQLException
{
return DriverManager.getConnection(URL,USER,PASSWORD);
}
}