四联表的级联查询（嵌套）

Posted 2022-04-15 普通网友

	@RequestMapping(value = "/list")
	public String list(Model model, HttpServletRequest request, String flag,
			String ghsId, String xsId, String ypId, String yyId)
			throws Exception 
		String sql = "select a.*,(select name from t_ghs b where a.ghsId=b.id) name ,(select name from t_xs b where a.xsId=b.id) man ,(select name from t_yp b where a.ypId=b.id) hao ,(select name from t_yy b where a.yyId=b.id) ni  from t_flow a where 1=1";

		if (ghsId != null && !"".equals(ghsId)) 
			sql += " and ghsId ="+ghsId;
		
		if (xsId != null && !"".equals(xsId)) 
			sql += " and xsId ="+xsId;
		
		if (ypId != null && !"".equals(ypId)) 
			sql += " and ypId ="+ypId;
		
		if (yyId != null && !"".equals(yyId)) 
			sql += " and yyId ="+yyId;
		
		sql += " order by id desc";
		List list = db.queryForList(sql);
		request.setAttribute("list", list);
		return "/admin/flow/list";
	
	

四联表的级联查询

    String sql = "select a.*,(select name from t_ghs b where a.ghsId=b.id) name ,(select name from t_xs b where a.xsId=b.id) man ,(select name from t_yp b where a.ypId=b.id) hao ,(select name from t_yy b where a.yyId=b.id) ni  from t_flow a where 1=1";