java操作mysql入门代码实例（含插入、更新和查询）

import java.sql.*;

public class mysql {
    public static string url = "jdbc:mysql://localhost:3306/test";//characterencoding=gbk
    public static string username = "root";
    public static string password = "root";
    public static connection con;
    public static statement stmt;
    public static resultset rs;

    public static void main(string[] args) throws sqlexception {
        connect();
        operation();
        stmt.close();
        con.close();
    }
    public static void test() {
        string sql_select = "select * from tablename where id=1";
        string sql_insert = "insert into tablename (col1,col2..) values('1','2'...)";
        string sql_update = "update tablename set colname='update' where id=1";
        //insert(sql_insert);
        //select(sql_select);
        //update(sql_update);
    }
    public static void connect() {
        // 定位驱动
        try {
            class.forname("com.mysql.jdbc.driver");
            system.out.println("加载驱动成功!");
        } catch (classnotfoundexception e) {
            system.out.println("加载驱动失败!");
            e.printstacktrace();
        }
        // 建立连接
        try {
            con = drivermanager.getconnection(url, username, password);
            stmt = con.createstatement();
            system.out.println("数据库连接成功!");
        } catch(sqlexception e) {
            system.out.println("数据库连接失败!");
        }
    }
    public static void select(string sql) {
        try {
            rs = stmt.executequery(sql);
            resultsetmetadata meta_data = rs.getmetadata();//列名
            for (int i_col = 1; i_col <= meta_data.getcolumncount(); i_col++) {
                system.out.print(meta_data.getcolumnlabel(i_col) + "   ");
            }
            system.out.println();
            while (rs.next()) {
                for (int i_col = 1; i_col <= meta_data.getcolumncount(); i_col++) {
                    system.out.print(rs.getstring(i_col) + "  ");
                }
                system.out.println();
            }
            rs.close();
        }catch (exception e) {
            system.out.println("数据查询失败!");
        }
    }
    public static void insert(string sql) {
        try {
            stmt.clearbatch();
            stmt.addbatch(sql);
            stmt.executebatch();
            system.out.println("数据插入成功!");
        }catch (exception e) {
            system.out.println("数据插入失败!");
        }

    }
    public static void update(string sql) {
        try {
            stmt.executeupdate(sql);
            system.out.println("数据更新成功!");
        }catch (exception e) {
            system.out.println("数据更新失败!");
        }
    }
}