CREATEFUNCTION[dbo].[F_CM_Split](@textVARCHAR(MAX),@delimiterVARCHAR(1)='')RETURNS@StringsTABLE( ITEM_VALUEVARCHAR(MAX) )ASBEGINDECLARE@indexINTSET@index=-1WHILE(LEN(@text)>0)BEGINSET@index=CHARINDEX(@delimiter,
1:use[MyDemo]2:go3:alterFUNCTIONDep_Salaries14:(5:@empid int6:)7:RETURNS@table table8:(9:Department int,10:Salary_Max int,11:Salary_Min int12:)13:AS14:BEGIN15:declare @Department int=(selectS.deptid from Employees s where s.empid=@empid)16:insert into @table17:SELECTS.deptid,max(...
1.TVF(表-值行数Table-Valued Functions) 一般情况,当使用TVF与一个对象内联接,如果该对象没有索引将会导致TVF像索引扫描或表扫描一样做扫描操作。 作为一个选择,可以创建临时表,临时表上创建适当的聚集索引或非聚集索引。 详情如下: 创建适当的临时表。 根据T-SQL创建适当的聚集索引和非聚集索引。 将TVF的数据...
Feature Computed columns Applies to: SQL Server 2014 (12.x) and SQL Server 2016 (13.x)Computed columns are not supported for memory-optimized tables. Remove the computed columns from the CREATE TABLE statement.Azure SQL Database and SQL Server starting SQL Server 2017 (14.x) do support comp...
CreateExternalStreamStatement CreateExternalTableStatement CreateFederationStatement CreateFullTextCatalogStatement CreateFullTextIndexStatement CreateFullTextStopListStatement CreateFunctionStatement CreateIndexStatement CreateLoginSource CreateLoginStatement CreateMasterKeyStatement CreateMessageTypeStatement CreateOrAlterFunction...
这次介绍一下T-SQL中“Not IN” 和“Not Exists”的优化。 Not IN 和 Not Exists 命令 : 有些情况下,需要select/update/delete 操作孤立数据。孤立数据:不存在主表中而存在其关联表中。 操作这样的数据,一般第一反应是利用“Not in” 或“Not Exists”命令。使用Not IN会严重影响性能,因为这个命令会逐一检查...
ScriptDom.Sql Namespace AddAlterFullTextIndexAction Class AddFileSpec Class AddSignatureStatement Class AdhocDataSource Class AdhocTableSource Class AffinityKind Enumeration AlgorithmKeyOption Class AlterAction Enumeration AlterApplicationRoleStatement Class AlterAssemblyStatement Class AlterAsymmetricKeyStatement ...
The former doesn't return the outer table's row if the table-valued function returns an empty set for it, while the latter returns a row with NULLs instead of the function's columns. To use the APPLY operator, first create the following Arrays table, which stores arrays of comma-...
SQL Server Usage String functions are typically scalar functions that perform an operation on string input and return a string or a numeric value. Syntax and Examples The following table includes the most commonly used string functions. FunctionPurposeExampleResult...
1:CREATE The simplified syntax is as follows: CREATETABLE[ database_name . [ schema_name ] . | schema_name . ] table_name ( column_name <data_type> [NULL|NOTNULL] [ ,...n ] ) 2:SQL Server 2005 Data Types bigint:Whole number from –2^63 (-9,223,372,036,854,775,808) thro...