java操作mysql入门代码实例（含插入、更新和查询）

浅沫记忆

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!");
    }
  }
}