JAVA连接数据库

 

package car.sql;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Vector;

import javax.swing.JOptionPane;
import javax.swing.table.DefaultTableModel;

public class Connect {
    private final static String url = "jdbc:sqlserver://localhost:1433;databaseName=S_CarDB";// 数据库连接地址
    private final static String user = "sa"; // 超级管理员
    private final static String password = "123456"; // 密码
    private static Connection conn = null;// SQL Connection
    private static Statement stmt;
    //数据库连接
    public Connect() {
        try {    
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");// 加载驱动
        } catch (Exception e1) {
            e1.printStackTrace();
        }
        try {
            conn = DriverManager.getConnection(url, user, password);// 连接数据库
            //System.out.println("数据库连接成功");
        } catch (Exception e2) {
            e2.printStackTrace();
            //System.out.println("数据库连接失败");
        }
    }
}

 

添加不同的方法调用数据库

 

public boolean compare(String num, String psd) {//判断账号密码是否正确
        boolean flag = false;
        String sql = "select Apassword from S_Admin where Anumber='"+num+"'";
        try {
            stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(sql);
            while (rs.next()) {
                String p = rs.getString(1);
                if (p.equals(psd)) {
                    flag = true;
                }
           // rs.close();
           // conn.close();
           // stmt.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return flag;
        }
public DefaultTableModel searchChargeStandard(String ctype)//查询收费标准
    {
        String sql = "SELECT Ctype , Cfee from S_Charge where Ctype like '%" + ctype + "%'";
        // 设置dataModel的表头
        DefaultTableModel dataModel = null;
        Vector<String> columns = new Vector<String>();
        columns.add("Ctype");
        columns.add("Cfee");
        dataModel = new DefaultTableModel(columns, 0);    
        try {
            stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(sql);
            while (rs.next()) {
                String c = rs.getString("Ctype");
                String f = rs.getString("Cfee");
                // 设置dataModel的数据
                Vector<Object> row = new Vector<Object>();
                row.add(c);
                row.add(f);
                dataModel.addRow(row);

                }
           // rs.close();
           // conn.close();
           // stmt.close();      
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return dataModel;
    }