Ò׽ؽØÍ¼Èí¼þ¡¢µ¥Îļþ¡¢Ãâ°²×°¡¢´¿ÂÌÉ«¡¢½ö160KB

³õѧÕß¡£Sqlserver nullµÄÎÊÌâ

´ÓÍøÉϲ鵽µÄ×ÊÁÏ˵£¬ÈκÎÊý¾ÝÀàÐÍÓëNULLÖµ½øÐмÆË㣬½á¹û¶¼½«ÎªNULL.

select null-1
½á¹ûÊÇnull

¿ÉÊÇÏÂÃæÕâ¸ö²éѯΪʲô»á³ö´íÄØ£¿
select isnull(null-1,'test');

¾ÓÈ»±¨´í˵½«varcharתΪintʧ°Ü¡£

Ϊʲô»á˵ת³Éintʧ°ÜÄØ£¿Ç°ÃæµÄnull-1µÄ½á¹û²»ÊÇnullô£¿Ôõô»¹»áȥת³Éint?

»·¾³sql server2000

лл»Ø´ð¡£
/

ºÇºÇ¡£È·ÊµÃ»×¢Òâ¹ý¡£Ó¦¸ÃÊÇnull-1½á¹ûÒþʽת»»³ÉÁËintÀàÐÍ¡£ËùÒԲŻá³öÏÖÕâ¸ö´íÎó¡£

http://blog.csdn.net/Beirut/archive/2009/08/11/4433706.aspx

³ýÁËcount£¨*£© ÍâÆäËû¾ÛºÏº¯Êý¶¼»áºöÂÔ¿ÕÖµ

ÒýÓÃ
http://blog.csdn.net/Beirut/archive/2009/08/11/4433706.aspx

³ýÁËcount£¨*£© ÍâÆäËû¾ÛºÏº¯Êý¶¼»áºöÂÔ¿ÕÖµ
SQL code:
Óï·¨

ISNULL ( check_expression , replacement_value )


²ÎÊý
check_expression

½«±»¼ì²éÊÇ·ñΪ NULL µÄ±í´ïʽ¡£check_expression ¿ÉÒÔΪÈκÎÀàÐÍ¡£

replacement_value

µ± check_expression Ϊ NULL ʱҪ·µ»ØµÄ±í´ïʽ¡£replacement_value ±ØÐëÊÇ¿ÉÒÔÒþʽת»»Îª check_expresssion ÀàÐ͵ÄÀàÐÍ¡£

·µ»ØÀàÐÍ
·µ»ØÓë check_expression ÏàͬµÄÀàÐÍ¡£

±¸×¢
Èç¹û check_expression ²»Îª NULL£¬Ôò·µ»ØËüµÄÖµ£»·ñÔò£¬ÔÚ½« replacement_value Òþʽת»»Îª check_expression µÄÀàÐÍ£¨Èç¹ûÕâÁ½¸öÀàÐͲ»Í¬£©ºó£¬Ôò·µ»ØÇ°Õß¡£


test±ØÐë¿ÉÒÔת»»ÎªÕûÐͲſÉÒÔ£¬Èç¹û»»Îª'1'¾Í¿ÉÒÔÁË

¿ÉÊÇÎÒÕâÀïºÃÏñûÓÐÓõ½¾ÛºÏº¯Êý°¡¡£
{{-


Ïà¹ØÎÊ´ð£º

¹ØÓÚSQLSERVERµ×²ãÎÊÌâ - MS-SQL Server / ÒÉÄÑÎÊÌâ

ÇëÎÊһϣ¬ÍâÍøÁ½Ì¨SQLSERVERʵÀýÊý¾Ý´«Ê䣬ÓÐûÓвÉÓÃÊý¾ÝѹËõºÍ¼ÓÃÜ¡£Ñ¹Ëõ±ÈÊǶàÉÙ£¬¼ÓÃÜÊÇʲô¼ÓÃÜËã·¨£¿Ïà¹ØÎĵµÄÄÀï¿ÉÒÔÕÒµ½£¿Ð»Ð»


ÎÒÒ²ÏëÖªµÀ£¡¹Ø×¢´ËÌù£¡

¹Ø×¢¡«¡«

Êý¾Ý¿â´óÅ£¶¼ÄÄÈ¥Á˰¡£¿
......

ÈçºÎ·ÀֹͬʱÏòSQLSERVERдÈëÊý¾Ý

Çë½Ì¸÷λ£º
ÔÚ³¬ÊеÄÊÕÒøÏµÍ³ÖУ¬Èç¹ûÓÐ20¶à¸ö¿Í»§¶Ë£¬ÓпÉÄÜͬʱ¶Ôij×Ö¶ÎÊý¾Ý½øÐÐÐ޸쬻ò½øÐÐɾ³ý£¬¾ÍÓпÉÄܾͻáÔì³ÉijЩ¿Í»§¶Ë³öÏÖ´íÎó£¬Ó¦¸ÃÈçºÎÈ¥±ÜÃâÄØ£¿ÄÜ·ñÌṩ¾ßÌåÊÂÀý£¬Ð»Ð»

Ôõô»áͬʱÐÞ¸ÄÄØ£¿ ......

sqlserver ÈçºÎÏÔʾ³ö<Long Text>ÀïµÄÊý¾Ý?

ÈçºÎÏÔʾ³ö <Long Text>ÀïµÄÊý¾Ý?


ÎÒÏëÎÊÄãÒ»ÏÂÔÚsqlÆóÒµ¹ÜÀíÆ÷Àï·µ»ØµÄ¼Ç¼ÖÐÈç¹û½« <Long Text>ÀïµÄÊý¾ÝÏÔʾ³öÀ´?


ÓÃÕâÖֵķ½Ê½¿ÉÒÔ¿´µ½ SELECT CONVERT(VARCHAR(5000),LONGTEX ......

PB10¡¢PB11Á¬½ÓSQLServer (×ªÔØ)

PB10¡¢PB11Á¬½ÓSQLServer¹Ø¼ü×Ö: pb10¡¢pb11Á¬½Ósqlserver (×ªÔØ)
PB10¡¢PB11Á¬½ÓSQLServer (×ªÔØ)
2007-11-02 22:27
´ÓPB10¿ªÊ¼£¬Ã»ÓÐÁËmssql serverרÓýӿÚÁË£¬ÁíÒ»·½ÃæÊý¾Ý¿â¹ÜÀíϵͳ(DBMS)
»»³ÉÁË ......

vc ado sqlserver´ò°ü·¢²¼ºóµÄÆæ¹ÖÎÊÌâ

Á½Ì¨µçÄÔ£º¿ª·¢»úºÍÄ¿±ê»ú¡£
¿ª·¢»ú »·¾³£ºvc6.0+sql server2000
Ä¿±ê»ú »·¾³£ºsql server2000

ʹÓÃÄ¿±ê»úÄ¿µÄ£º²âÊÔ³ÌÐòÊÇ·ñÄܳɹ¦·¢²¼µ½Ã»ÓÐvc»·¾³µÄpcÉÏ¡£

²½Ö裺
1.½«¿ª·¢»úÉϵÄÊý¾ ......
© 2009 ej38.com All Rights Reserved. ¹ØÓÚE½¡ÍøÁªÏµÎÒÃÇ | Õ¾µãµØÍ¼ | ¸ÓICP±¸09004571ºÅ