jdbc

1. 添加依赖（因为创建的是maven项目 所以不用去创建lib目录去导入包了 方便）

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 <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
    </dependencies>

**2.url password等等** `driverClass=com.mysql.cj.jdbc.Driver url=jdbc:mysql://127.0.0.1:3306/user?serverTimezone=UTC&&useSSL=false user=root password=root` **3.idea代码jdbc连接**

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import java.sql.*;

public class jdbc_web {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
     String   url="jdbc:mysql://127.0.0.1:3306/user?serverTimezone=UTC&&useSSL=false";
     String   username="root";
     String   password="root";
     Class.forName("com.mysql.jdbc.Driver");
        Connection connection = DriverManager.getConnection(url, username, password);
        Statement statement = connection.createStatement();
        ResultSet resultSet = statement.executeQuery("select * from student");
        while(resultSet.next()){
            System.out.println("name:"+resultSet.getObject("name"));
            System.out.println("age:"+resultSet.getObject("age"));
            System.out.println("address:"+resultSet.getObject("address"));
            System.out.println("brithday:"+resultSet.getObject("brithday"));
        }
        resultSet.close();
        statement.close();
        connection.close();
    }
}

**4.mysql 预处理**

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public class jdbc01 {
    public static void main(String[] args) throws ClassNotFoundException, SQLException {
        String   url="jdbc:mysql://127.0.0.1:3306/user?serverTimezone=UTC&&useSSL=false";
        String   username="root";
        String   password="root";
        Class.forName("com.mysql.jdbc.Driver");
        Connection connection = DriverManager.getConnection(url, username, password);
        String sql="INSERT INTO  student (name,age,address,brithday)values(?,?,?,?)";
        PreparedStatement preparedStatement = connection.prepareStatement(sql);
        preparedStatement.setString(1,"小王");
        preparedStatement.setInt(2,14);
        preparedStatement.setString(3,"上海");
        preparedStatement.setDate(4, new java.sql.Date(System.currentTimeMillis()));

        int i = preparedStatement.executeUpdate();
      if(i>0){
            System.out.println("加入成功");
        }else {
          System.out.println("加入失败");
      }
        preparedStatement.close();
        connection.close();
    }
}