2007年11月小记

1、使用SQL2005的XML类型分拆字符串。

DECLARE   @TagNames  XML;
SET   @TagNames   =   ' <?xml version="1.0" encoding="utf-8"?><ArrayOfString xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><string>asp.net</string><string>sql</string><string>ajax</string></ArrayOfString> ' ;

DECLARE   @TagNameTable   TABLE ( [ IndexId ]   INT   IDENTITY ( 1 , 1 )  NOT   NULL   PRIMARY   KEY ,  [ TagName ]   NVARCHAR ( 200 )  NOT   NULL )
     INSERT   INTO   @TagNameTable
         SELECT  tab.col.value( ' text()[1] ' , ' nvarchar(200) ' )  AS   [ TagName ]
         FROM   @TagNames .nodes( ' /ArrayOfString/string ' )  AS  tab(col);

select   *   from   @TagNameTable   order   by   [ IndexId ]

2、使网页中所有链接都另页打开

< head >
     < base  target ="_blank"   />
</ head >

3、Lambda表达式一例

         static   void  Main( string [] args)
         {
            var strs = new List<string> { "A1", "A2", "A3" };
            List<string> list = new List<string>();

            //使用匿名委托
            strs.ForEach(delegate(string str) { Console.WriteLine(str); });

            //使用Lambda表达式
            strs.ForEach(x => list.Add(x.TrimStart('A')));
            list.ForEach(x => Console.WriteLine(x));

            Console.ReadLine();
        }

4、WCF:ABC 从何地以何种方式绑定何种契约
5、如何成功调用 wsHttpBinding邦定的WCF服务?
服务器定义了dns，如：

   < system .serviceModel >
     < services >
       < service  behaviorConfiguration ="passportServiceBehavior"  name ="CJB.Passport.Service.PassportService" >
         < endpoint  address =""  binding ="wsHttpBinding"  contract ="CJB.Passport.Contract.IPassportService" >
           < identity >
             < dns  value ="localhost"   />
           </ identity >
         </ endpoint >
         < endpoint  address ="mex"  binding ="mexHttpBinding"  contract ="IMetadataExchange"   />
       </ service >
     </ services >
     < behaviors >
       < serviceBehaviors >
         < behavior  name ="passportServiceBehavior" >
           < serviceMetadata  httpGetEnabled ="true"   />
           < serviceDebug  includeExceptionDetailInFaults ="true"   />
         </ behavior >
       </ serviceBehaviors >
     </ behaviors >
   </ system.serviceModel >

客户端也要配置dns，此dns可以为服务器计算机名称，如：

     < system .serviceModel >
         < client >
             < endpoint  address ="http://passport2.ruiya.com/WcfService/PassportService.svc"
                binding ="wsHttpBinding"  bindingConfiguration =""  contract ="CJB.Passport.Contract.IPassportService"
                name ="iisHostEndpoint" >
                 <identity>
                     <dns value="cjb"/>
                 </identity>
             </ endpoint >
         </ client >
     </ system.serviceModel >

或者<dns value="localhost"/>
6、注意 between ... and ...在使用变量和使用拼接字符串中不过的执行计划导致的性能问题：

     declare   @handleTime   datetime ;
     declare   @beginTime   datetime ;
     declare   @endTime   datetime ;
     set   @handleTime   =   DateAdd ( day ,  - 1 ,  getdate ());
     set   @beginTime   =   CONVERT ( datetime ,  CONVERT ( char ( 10 ),  @handleTime ,  120 ));
     set   @endTime   =   DateAdd ( day ,  1 ,  @beginTime );

     declare   @sql   nvarchar ( 1000 );
     set   @sql   =   ' SELECT * FROM [UserPosts] WITH(NOLOCK) WHERE ([AddTime] between  '''   +
         cast ( @beginTime   as   nvarchar ( 100 ))  +   '''  AND  '''   +   cast ( @endTime   as   nvarchar ( 100 ))  +   ''' ) ' ;
     -- print @sql
    
     declare   @st   datetime
     declare   @et   datetime

     set   @st   =   getdate ();
     exec ( @sql );
     set   @et   =   getdate ();
     select   datediff (millisecond,  @st ,  @et );

     set   @st   =   getdate ();
     select   *   from   [ UserPosts ]   WITH (NOLOCK)  WHERE  ( [ AddTime ]   between   @beginTime   and   @endTime );
     set   @et   =   getdate ();
     select   datediff (millisecond,  @st ,  @et );

拼接字符串: 0ms
使用变量： 23106ms
7、SQL拆分字符串

CREATE   PROCEDURE   [ dbo ] . [ ec_System_SplitString ]
     @strs   nvarchar ( 4000 ),
     @separator   nchar ( 1 ) = ' , '
AS
BEGIN
     SET  NOCOUNT  ON ;

     DECLARE   @tbNames      table ( [ Name ]   nvarchar ( 256 )  NOT   NULL   PRIMARY   KEY )
     DECLARE   @Num          int ;
     DECLARE   @Pos          int ;
     DECLARE   @NextPos      int ;
     DECLARE   @Name          nvarchar ( 256 );
     SET   @Num   =   0 ;
     SET   @Pos   =   1 ;

     WHILE ( @Pos   <=   LEN ( @strs ))
     BEGIN
         SELECT   @NextPos   =   CHARINDEX ( @separator ,  @strs ,   @Pos )
         IF  ( @NextPos   =   0   OR   @NextPos   IS   NULL )
             SELECT   @NextPos   =   LEN ( @strs )  +   1
         SELECT   @Name   =   RTRIM ( LTRIM ( SUBSTRING ( @strs ,  @Pos ,  @NextPos   -   @Pos )))
         SELECT   @Pos   =   @NextPos + 1

        
         INSERT   INTO   @tbNames   VALUES  ( @Name )
         SET   @Num   =   @Num   +   1
     END

     SELECT   [ Name ]   FROM   @tbNames

END