sql server ¶¨ÒåÖ÷¼ü
drop table father;
create table father(
id int identity(1,1) primary key,
name varchar(20) not null,
age int not null
)
drop table mother;
create table mother(
id int identity(1,1),
name varchar(20) not null,
age int not null,
husband int not null
)
alter table mother
add constraint FK_ID foreign key(husband) references father(id)
Èç¹û ÔÚfatherÖÐûÄܶ¨ÒåÖ÷¼ü£¬
drop table father;
create table father(
id int identity(1,1), (䶨Òå primary key)
name varchar(20) not null,
age int not null
)
Ôò»á±¨ÈçÏÂÒì³££º
ÔÚ±»ÒýÓñí 'father' ÖÐûÓÐÓëÍâ¼ü 'FK_ID' µÄÒýÓÃÁеÄÁÐ±íÆ¥ÅäµÄÖ÷¼ü»òºòÑ¡¼ü
Ïà¹ØÎĵµ£º
ʹÓÃ×Ó²éѯµÄÔÔò
1.Ò»¸ö×Ó²éѯ±ØÐë·ÅÔÚÔ²À¨ºÅÖС£
2.½«×Ó²éѯ·ÅÔڱȽÏÌõ¼þµÄÓÒ±ßÒÔÔö¼Ó¿É¶ÁÐÔ¡£
×Ó²éѯ²»°üº¬ ORDER BY ×Ӿ䡣¶ÔÒ»¸ö SELECT Óï¾äÖ»ÄÜÓÃÒ»¸ö ORDER BY ×Ó¾ä,
&nb ......
±È½ÏÁ½¸öSQLµÄÖ´ÐÐʱ¼ä
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[PROC_SQL_COMP]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop procedure [dbo].[PROC_SQL_COMP]
GO
/*--²âÊÔÁ½×éSQLµÄƽ¾ùʱ¼ä
ÀûÓÃosql.exeÀ´²âÊÔÁ½×é SQL Óï¾äµÄÖ´ÐÐʱ¼ä
²âÊԵĴ洢¹ý³ ......
簡體數據庫轉·±體數據庫µÄ問題 °ÝÍÐÁË
ALTER DATABASE DatabaseName SET SINGLE_USER WITH ROLLBACK IMMEDIATE
ALTER DATABASE DatabaseName COLLATE Chinese_Taiwan_Stroke_CI_AS
ALTER DATABASE DatabaseName SET MULTI_USER WITH ROLLBACK ......
...
)
Óõ½µÄ¹¦ÄÜÓÐ:
1.Èç¹ûÎÒ¸ü¸ÄÁËѧÉúµÄѧºÅ,ÎÒÏ£ÍûËûµÄ½èÊé¼Ç¼ÈÔÈ»ÓëÕâ¸öѧÉúÏà¹Ø(Ò²¾ÍÊÇͬʱ¸ü¸Ä½èÊé¼Ç¼±íµÄѧºÅ);
2.Èç¹û¸ÃѧÉúÒѾ ......
¾¡Á¿ÉÙÓÃIN²Ù×÷·û£¬»ù±¾ÉÏËùÓеÄIN²Ù×÷·û¶¼¿ÉÒÔÓÃEXISTS´úÌæ¡£
²»ÓÃNOT IN²Ù×÷·û£¬¿ÉÒÔÓÃNOT EXISTS»òÕßÍâÁ¬½Ó+Ìæ´ú¡£
OracleÔÚÖ´ÐÐIN×Ó²éѯʱ£¬Ê×ÏÈÖ´ÐÐ×Ó²éѯ£¬½«²éѯ½á¹û·ÅÈëÁÙʱ±íÔÙÖ´ÐÐÖ÷²éѯ¡£¶øEXISTÔòÊÇÊ×Ïȼì²éÖ÷²éѯ£¬È»ºóÔËÐÐ×Ó²éѯֱµ½ÕÒµ½µÚÒ»¸öÆ¥ÅäÏî¡£NOT EXISTS±ÈNOT INЧÂÊÉԸߡ£µ«¾ßÌåÔÚÑ¡ÔñIN»òEXIST² ......