jdbc连接数据库

最新推荐文章于 2024-10-07 23:02:18 发布

转载最新推荐文章于 2024-10-07 23:02:18 发布 · 618 阅读

本文提供了一个使用 Java JDBC 连接 MySQL 数据库并进行基本操作的例子，包括插入数据和查询数据的功能实现。

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import java.sql.*;

public class TestJDBC{
	public static void main(String[] args){
		ResultSet rs=null;
		Statement stmt=null;
		Connection conn=null;


        try{
		    Class.forName("com.mysql.jdbc.Driver");
		    conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/my_database","root","mima");
		    stmt=conn.createStatement();
		    rs=stmt.executeQuery("select * from student");
		    while(rs.next()){
			    System.out.println(rs.getInt("id"));
			    System.out.println(rs.getString("name"));
		    }
	    }catch(ClassNotFoundException e){
	    	System.out.println("class not found");
	    	e.printStackTrace();
	    }catch(SQLException e){
	    	e.printStackTrace();
	    }finally{
	    	try{
	    	    if(rs!=null){
	    		    rs.close();
	    		    rs=null;
	    	    }
	    	    if(stmt!=null){
	    		    stmt.close();
	    		    stmt.close();
	    	    }
	    	    if(conn!=null){
	    		    conn.close();
	    		    conn=null;
	    	    }
	    	}catch(SQLException e){
	    		e.printStackTrace();
	    	}
	    }
	}
	
}

package com.hibernate.model;

import java.sql.*;

public class TestJDBC {
	public static void main(String[] args) {

		if (args.length != 3) {
			System.out.println("paraments is not right");
			System.exit(-1);

		}
		int id = 0;
		try {

			id = Integer.parseInt(args[0]);
		} catch (NumberFormatException e) {
			System.out.println("id should be number format");
			System.exit(-1);
		}
		String name = args[1];
		String loc = args[2];

		Statement stmt = null;
		Connection conn = null;

		try {
			Class.forName("com.mysql.jdbc.Driver");
			conn = DriverManager.getConnection(
					"jdbc:mysql://localhost:3306/my_database", "root",
					"fangqiang");
			stmt = conn.createStatement();
			String sql = "insert into student values (" + id + ",'" + name
					+ ",'" + loc + "')";  //数值不加单引号，字符串加单引号
			System.out.println(sql);
			stmt.executeUpdate(sql);

		} catch (ClassNotFoundException e) {
			System.out.println("class not found");
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {

				if (stmt != null) {
					stmt.close();
					stmt.close();
				}
				if (conn != null) {
					conn.close();
					conn = null;
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
}

package com.hibernate.model;

import java.sql.*;

public class TestJDBC {
	public static void main(String[] args) {

		if (args.length != 3) {
			System.out.println("paraments is not right");
			System.exit(-1);

		}
		int id = 0;
		try {

			id = Integer.parseInt(args[0]);
		} catch (NumberFormatException e) {
			System.out.println("id should be number format");
			System.exit(-1);
		}
		String name = args[1];
		String loc = args[2];

		PreparedStatement pstmt = null;
		Connection conn = null;

		try {
			Class.forName("com.mysql.jdbc.Driver");
			conn = DriverManager.getConnection(
					"jdbc:mysql://localhost:3306/my_database", "root",
					"fangqiang");
			pstmt = conn.prepareStatement("insert into student values (?,?,?)");
			
			pstmt.setInt(1, id);
			pstmt.setString(2, name);
			pstmt.setString(3, loc);
			pstmt.executeUpdate();

		} catch (ClassNotFoundException e) {
			System.out.println("class not found");
			e.printStackTrace();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {

				if (pstmt != null) {
					pstmt.close();
					pstmt.close();
				}
				if (conn != null) {
					conn.close();
					conn = null;
				}
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}
}