dbsql.java

一个关于列表框值的修改的源代码

package listsql;

import java.sql.Connection;
import javax.swing.JOptionPane;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.ResultSet;
import java.sql.Statement;

public class dbsql {
  Connection con = null;
  String user = "sa";
  String pwd = "";
  String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=zcmt";

  public boolean connect() {
    try {
      Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
      con = DriverManager.getConnection(url, user, pwd);
    }
    catch (ClassNotFoundException ex) {
      JOptionPane.showMessageDialog(null, ex.toString());
    }
    catch (SQLException ex) {
      JOptionPane.showMessageDialog(null, ex.toString());
    }

    return true;
  }

  public ResultSet query(String sql) {
    ResultSet rs = null;
    Statement st;
    if (con == null) {
      connect();
    }

    try {
      st = con.createStatement();
      rs = st.executeQuery(sql);
      return rs;
    }
    catch (SQLException ex) {
      JOptionPane.showMessageDialog(null, ex.toString());
      return null;
    }
  }

  public boolean update(String sql) {
    Statement st;
    int mcount;
    if (con == null) {
      connect();
    }
    try {
      st = con.createStatement();
      mcount = st.executeUpdate(sql);
      if (mcount < 1) {
        return false;
      }
    }
    catch (SQLException ex) {
      JOptionPane.showMessageDialog(null, ex.toString());
    }
    return true;
  }

  public boolean close() {
    try {
      con.close();
    }
    catch (SQLException ex) {
      JOptionPane.showMessageDialog(null, ex.toString());
    }
    con = null;
    return false;
  }
}