5: create table #table (empidint, empname varchar (25),Department varchar (25) ,Salaryint) 6: create clustered index #table_index1 on #table (empid asc ) 7: create nonclustered index #table_index2 on #table (Salary) include (Department,empid ) 8: insert into #table select S.empid,...
IF EXISTS(SELECT * FROM SYSINDEXES WHERE NAME='IX_TEST_TNAME')--检测是否已经存在IX_TEST_TNAME索引 DROP INDEXTEST.IX_TEST_TNAME--如果存在则删除 --创建索引 CREATE NONCLUSTERED INDEXIX_TEST_TNAME--创建一个非聚集索引 ON TEST(TNAME)--为TEST表的TNAME字段创建索引 WITH FILLFACTOR = 30--填充...
使用T-SQL命令创建、删除索引 代码如下：USELibrarymanageGOCREATENONCLUSTEREDINDEXNonClusteredIndex_BorrowreturninfoONBorrowreturninfo(Book_IDASC,Reader_IDASC)GO 使用T-SQL命令创建、删除索引 使用T-SQL语句创建索引 实践操作：利用SQL语句在图书管理系统（Librarymanage）数据库中为Borrowreturninfo的Borrow_ID列建立...
TSQL是查询SQL Server的核心,而索引则是提高查询效能的主角,如要写出高效能TSQL则无可避免需搭配正确索引,因为SQL Server需透过正确索引才可以快速有效地找到与索引键值相关数据,有了正确索引SQL Server就不需要扫描数据页(data page)上每一笔数据,而在众多查询效能调校技术中,透过建立并设计正确索引算是最基本的手法...
1:create tableschema_table(empid int,empnamevarchar(25),Departmentvarchar(25),Salary int)2:create clustered index schema_table_index1 onschema_table(empid asc)3:create nonclustered index schema_table_index2 onschema_table(Salary)include(Department,empid)4:insert into schema_table selectS.empid,S...
在SQL Server 2014 (12.x) 中,經記憶體最佳化的資料表不支援 FOREIGN KEY 條件約束。 功能 叢集索引 指定非叢集索引。 對於主索引鍵索引,請務必指定 PRIMARY KEY NONCLUSTERED。 功能 交易內的 DDL 記憶體最佳化資料表和原生編譯預存程序無法在使用者交易內容中建立或卸除。 請不要啟...
SQL 複製 CREATE TABLE dbo.SalesOrder ( SalesOrderId integer not null IDENTITY PRIMARY KEY NONCLUSTERED, CustomerId integer not null, OrderDate datetime not null ) WITH (MEMORY_OPTIMIZED = ON, DURABILITY = SCHEMA_AND_DATA); 針對記憶體最佳化資料表的 Transact-SQL INSERT 和 SELECT 陳...
SQLALTER TABLE Production.Categories ADD CONSTRAINT UC_Categories UNIQUE (categoryname); GO Like the primary key constraint, the unique constraint automatically creates a unique index with the same name as the constraint. By default, the index will be nonclustered. SQL uses that index to enforce ...
create nonclustered index idx_contact_names on Person.Contact(FirstName, LastName) Now, let’s say there’s another application which fires another query on this table, and that query looks like this: SELECT ContactID from Person.Contact WHERE LastName = ‘Alberts’ and FirstName = ‘Amy’...
Nonclustered Hash Indexes Show 3 more Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Memory-optimized tables, natively compiled stored procedures, and user-defined functions do not support the full Transact-SQL surface area that is supported by disk-based tables, interpreted...