一个连接数据库的工具类（JDBC）

最新推荐文章于 2025-08-01 11:22:09 发布

sunvsjay1890

最新推荐文章于 2025-08-01 11:22:09 发布

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CC 4.0 BY-SA版权

文章标签： jdbc 数据库工具 null exception oracle

本文链接：https://blog.youkuaiyun.com/sunvsjay1890/article/details/8059213

本文介绍了如何使用Java连接并查询Oracle数据库，以及如何使用Java连接并操作Access数据库，包括查询、插入、更新和删除操作。

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 public Set<Emp>  query(){               

        Connection conn = null;
	    PreparedStatement pstat = null;
	   ResultSet rst = null;
        HashSet<Emp> results=null;
  try {         
        Class.forName("oracle.jdbc.OracleDriver");
		conn = DriverManager.getConnection(
				"jdbc:oracle:thin:@localhost:1521:bluedot","scott","tiger");
	    pstat = conn.prepareStatement("select count(*) from emp");
	    
		rst = pstat.executeQuery();
	    results=new HashSet<Emp>();
			while(rst.next()){
				Emp emp=new Emp(rst.getInt("EMPNO"),
						        rst.getString("ENAME"),
						        rst.getString("JOB"),
						        rst.getInt("MGR"),
						        rst.getDate("HIREDATE"),
						        rst.getFloat("SAL"),
						        rst.getFloat("COMM"),
						        rst.getInt("DEPTNO"));
				 //System.out.println(emp.getEname()+"------------->"+emp.getJob());
				results.add(emp);
                  }

			if (rst != null) {
				rst.close();
			}
			if (pstat != null) {
				pstat.close();
			}
			if (conn != null) {
				conn.close();
			}
		} catch (Exception e) {
			throw new RuntimeException(e.getMessage());
		}
}

jdbc 连接access的问题

http://zhidao.baidu.com/question/89896669.html&__bd_tkn__=67b25a392e2585337f08a93fa1f521bd894588ad8078338d51fed8133ea5c69d362ad36bb4bcda3b39bb3949f6bbe47087ac3af56e60b1f4e7eb60157055f53b9b61aff140491fc7006f350ddc3bba7b487f9a030a29bffcd3393e097429462dc46508323dc7a8de947eeabbc9da890bcf3126f64b

public static void main(String[] args) {
  Connection conn = null;
   try {
   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
   String dburl ="jdbc:odbc:driver={Microsoft Access Driver (*.mdb)};DBQ=D:\\project\\Core_Java\\db\\yxbdata.mdb";//此为NO-DSN方式
   
//String dburl ="jdbc:odbc:odbcName";//此为ODBC连接方式
  
 conn = DriverManager.getConnection(dburl);
   
Statement stmt=conn.createStatement();
//   stmt.executeUpdate("insert into class(classid,classname) values(4,'arthurs')");
//   ResultSet rs=stmt.executeQuery("select Top 20 * from MobileSection");
 
  ResultSet rs=stmt.executeQuery("select * from class");
   while(rs.next()){
    System.out.println(rs.getString("classId")+","+rs.getString("classname"));
   }
  } catch (Exception e) {
   e.printStackTrace();
  }finally{
   try {
    if(conn != null){
     conn.close();
    }
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
    
 }