Introduction This article present a tiny database engine which implements fixed width record tables and BTree indexes. This library is a work in progress, I am looking for some feedback on this to see if there is a need for it. This article is also
jquery 简化了 ajax的开发 using System; using System.Web; using System.Web.SessionState; public class HandingPersonInfo : IHttpHandler,IReadOnlySessionState { public void ProcessRequest (HttpContext context) { context.Response.ContentType = "text/plain";
COALESCE()函数可以接受一系列的值,如果列表中所有项都为空(null),那么只使用一个值。然后,它将返回第一个非空值。这一技巧描述了创造性使用SQL Server 中COALESCE()函数的两种方法。
这里有一个简单的例子:有一个Persons数据表,它有三个字段FirstName、MiddleName和LastName。表中包含以下值:
John A. MacDonald
Franklin D. Roosevelt
Madonna
Cher