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,...
CREATE INDEX index_name on table_name (column1, column2) 隐式索引(Implicit Indexes)# 当创建primary key constraints and unique constraints.时会自动创建隐士索引 全文索引# 一种特殊类型的基于标记的功能性索引,由Microsoft SQL Server全文引擎生成和维护。用于帮助在字符串数据中搜索复杂的词。这种索引的结构...
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...
USE CPXScreate unique nonclustered index ind_cpon 产品(产品名称 DESC) 例:通过执行系统存储过程,显示产品表的索引文本。 bash exec sp_helpindex 产品 exec sp_rename 原视图名称, 新视图名称 perl use 学生课程数据库goexec sp_rename 'old_name','new_name' 例:删除ind_cp索引。 fortran USE CPXSdrop i...
CREATE UNIQUE CLUSTERED INDEX idx_depth_first ON dbo.Employees(hid); CREATE UNIQUE INDEX idx_breadth_first ON dbo.Employees(lvl, hid); Inserting New Nodes To insert a node into the hierarchy, you must first produce a new HIERARCHYID value that represents the correct position in the hierarchy....
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 the uniqueness of the column or combination of columns. ...
下面的T-SQL可以生成索引在当前数据库的外键上, 可以帮助我们找回外键上丢失的索引,查看索引命名是否规范。 -- declare memory table DECLARE @INDEX_TABLE TABLE( primary_key INT IDENTITY(1,1) NOT NULL, schema_name NVARCHAR(100), table_name NVARCHAR(100), column_name NVARCHAR(100), new_index_name ...
@@error值都会变 select @@language;--返回当前所用语言的名称 select @@rowcount;--返回受上一语句影响的行数 select @@servername;--返回运行 SQL Server 的本地服务器的名称 select @@trancount;--返回当前连接的活动事务数 select @@max_connections;--返回 SQL Server 实例允许同时进行的最大用户连接数...
SELECT * INTO MySalesOrderHeader FROM SalesOrderHeader CREATE UNIQUE CLUSTERED INDEX idx_uc_OrderDate_SalesOrderID ON MySalesOrderHeader(OrderDate, SalesOrderID) To delete all rows with an order year earlier than 2003 in batches of 1,000, use the following code: Copy WHILE 1 = 1 BEGIN DELE...
1:--创建新表2:use MyDemo3:CREATETABLE[dbo].[Employees](4:[empid][int]IDENTITY(1,1)NOTNULL,5:[empname][nvarchar](100)NULL,6:[deptid][int]NULL,7:[Salary][float]NULL,8:CONSTRAINT[PK_Employees]PRIMARYKEYCLUSTERED9:([empid]ASC)10:WITH11:(PAD_INDEX=OFF,STATISTICS_NORECOMPUTE=OFF,IGNORE...