databaseoperate.java

用java编写的人事管理系统,很好的 学习下吧

/**
 * 源文件：DatabaseOperate.java
 * 作用：得到数据库中的表和数据
 */
package mypro;

import java.sql.*;
import java.util.*;

public class DatabaseOperate
{
	private Connection con=DatabaseConnection.getConnection();
	/*通过表名得到列名*/
    public Vector getColumnNamesByTabname(String tabname)
    {
        Vector cols = new Vector();
        try
        {
            Statement sta = con.createStatement();
            String strSql = "SELECT * FROM " + tabname + " WHERE 1<>1";
            ResultSet rs = sta.executeQuery(strSql);
            ResultSetMetaData rsmd = rs.getMetaData();
            int colCount = rsmd.getColumnCount();
            for (int i = 1; i <= colCount; i++)
            {
                cols.add(rsmd.getColumnName(i));
            }
            rs.close();
            sta.close();
        }
        catch (SQLException sqle)
        {
            sqle.printStackTrace();
        }
        
        return (cols);
    }
    /*通过表明得到表中数据*/
    public Vector getDataByTabname(String tabname)
    {
        Vector data = new Vector();
        try
        {
            Statement sta = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
                                                ResultSet.CONCUR_READ_ONLY);
            String strSql = "SELECT * FROM " + tabname;
            ResultSet rs = sta.executeQuery(strSql);
            int cols = rs.getMetaData().getColumnCount();
            while (rs.next())
            {
                Vector vec = new Vector();
                for (int i = 1; i <= cols; i++)
                {
                    vec.add(rs.getObject(i));
                }
                data.add(vec);
            }
            rs.close();
            sta.close();
        }
        catch (SQLException sqle)
        {
            sqle.printStackTrace();
        }
        
        return (data);
    }
    /*得到表名*/
    public Vector getAllTabelName()
    {
        Vector vec = new Vector();
        try
        {
            Statement sta = con.createStatement();
            String strSql = "SELECT [name] AS tab_name FROM sysobjects WHERE xtype='U' ORDER BY [name]";
            ResultSet rs = sta.executeQuery(strSql);
            while (rs.next())
            {
                vec.add(rs.getString("tab_name"));
            }
            rs.close();
            sta.close();
        }
        catch (SQLException sqle)
        {
            sqle.printStackTrace();
        }
        
        return (vec);
    }
    /*得到除users以外的表名*/
    public Vector getAllTabelNameExceptUsers()
    {
        Vector vec = new Vector();
        try
        {
            Statement sta = con.createStatement();
            String strSql = "SELECT [name] AS tab_name FROM sysobjects WHERE xtype='U' and [name] !='users' ORDER BY [name]";
            ResultSet rs = sta.executeQuery(strSql);
            while (rs.next())
            {
                vec.add(rs.getString("tab_name"));
            }
            rs.close();
            sta.close();
        }
        catch (SQLException sqle)
        {
            sqle.printStackTrace();
        }
        
        return (vec);
    }
    
}