下面的语句如何优化呢?关于left join的优化--高分相求 已经较优了.不过,如果 topics 与 dnt_attachments 是一对多关系的话,以 dbo.dnt_topics 作为主表会好一些。没附件的主题加 WHERE 条件子句过滤掉。 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 e.g.USE [AdventureWorks]GOCREATE UNIQUE NONCLUSTERED INDEX [IX_Address_AddressLine1_AddressLine2_City_StateProvinceID_PostalCode] ON [Person].[Address] ( [AddressLine1] ASC, [AddressLine2] ASC, [City] ASC, [StateProvinceID] ASC, [PostalCode] ASC)WITH (SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF) ON [PRIMARY]GOEXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'Nonclustered index.' , @level0type=N'SCHEMA', @level0name=N'Person', @level1type=N'TABLE', @level1name=N'Address', @level2type=N'INDEX', @level2name=N'IX_Address_AddressLine1_AddressLine2_City_StateProvinceID_PostalCode' 关于在SqlServer中使用current_date的问题! 请大家帮帮忙了!! 如何获取表字段的类型??? 新手求教~~ 如何删除数据重复的行 求一个SQL语句 数据库恢复后,MDF无法附加,求教. 这个SQL怎么写?好象是不行的,但是我不能确认:就是在表1中用两次LEFT JOIN 到相... 求助关于EXISTS和IN在结果上有区别吗 SQL Server 2000数据库的内容怎么转到SQL Server 2008里面 sql 语句性能优化 怎么删除主键的值
GO
CREATE UNIQUE NONCLUSTERED INDEX [IX_Address_AddressLine1_AddressLine2_City_StateProvinceID_PostalCode] ON [Person].[Address]
(
[AddressLine1] ASC,
[AddressLine2] ASC,
[City] ASC,
[StateProvinceID] ASC,
[PostalCode] ASC
)WITH (SORT_IN_TEMPDB = OFF, DROP_EXISTING = OFF, IGNORE_DUP_KEY = OFF, ONLINE = OFF) ON [PRIMARY]
GO
EXEC sys.sp_addextendedproperty
@name=N'MS_Description',
@value=N'Nonclustered index.' ,
@level0type=N'SCHEMA',
@level0name=N'Person',
@level1type=N'TABLE',
@level1name=N'Address',
@level2type=N'INDEX',
@level2name=N'IX_Address_AddressLine1_AddressLine2_City_StateProvinceID_PostalCode'