子查询是一个嵌套在SELECT、INSERT、UPDATE或DELETE语句或其他子查询中的查询。 本文中的 Transact-SQL 代码示例使用AdventureWorks2022或AdventureWorksDW2022示例数据库,可从Microsoft SQL Server 示例和社区项目主页下载它。 任何允许使用表达式的地方都可以使用子查询。 在此示例中,子查询用作SELECT语句中名为 MaxUnitPri...
SELECT message_id AS Error, severity AS Severity, [Event Logged] = CASE is_event_logged WHEN 0 THEN 'No' ELSE 'Yes' END, [text] AS [Description] FROM sys.messages WHERE language_id = 1040 /* replace 1040 with the desired language ID, such as...
SELECT BusinessEntityID, VacationHours FROM HumanResources.Employee WHERE BusinessEntityID = 4; -- This statement, which caused the snapshot transaction -- to fail, will succeed with read-committed using row versioning. UPDATE HumanResources.Employee SET SickLeaveHours = SickLeaveHours -...
SELECT row_group_id,cast(deleted_rows as float)/cast(total_rows as float)*100 as [% fragmented], created_time FROM sys. dm_db_column_store_row_group_physical_stats WHERE object_id = object_id('FactOnlineSales2') AND state_desc='COMPRESSED' AND...
/* 这个题目翻译成大白话就是:查询有多少人选了课程 select 学号,成绩表里学号有重复值需要去掉 from 从课程表查找score; */ select count(distinct 学号) as 学生人数 from score; 查询各科成绩最高和最低的分, 以如下的形式显示:课程号,最高分,最低分 /* 分析思路 select 查询结果 [课程ID:是课程号的别...
sys.dm_db_column_store_row_group_physical_stats 有助您判斷特定索引、資料表內所有索引,或資料庫內所有索引中,每個資料列群組的資料列總數和已刪除的資料列數。 由sys.dm_db_column_store_row_group_physical_stats 所傳回的結果集包含下列資料行: 展開資料表 資料行描述 total_rows 實際儲存在資料列群組...
SELECTCAST([Level]ASNVARCHAR(100))AS[ConvertedLevel], *FROMBasicDemoORDERBY[Level]; 结果集如下。 输出 Converted Level Level Location LocationType --- --- --- --- /1/ 0x58 Europe Continent /1/1/ 0x5AC0 France Country /1/1/1/ 0x5AD6 Paris City /1/2/ 0x5B40 Spain Country /1/...
SELECT*FROMOPENROWSET(BULKN'D:\XChange\test-csv.csv', FORMATFILE = N'D:\XChange\test-csv.fmt', FIRSTROW=2,FORMAT='CSV')AScars; FORMATFILE = 'format_file_path' 指定格式化文件的完整路径。 SQL Server 支持两种格式化文件类型:XML 和非 XML。
下列範例會計算SalesOrderHeader資料表中所有資料列的編號,並以OrderDate順序排列,然後只傳回包含50至60的資料列。 SQL USEAdventureWorks2022; GOWITHOrderedOrdersAS(SELECTSalesOrderID, OrderDate, ROW_NUMBER()OVER(ORDERBYOrderDate)ASRowNumberFROMSales.SalesOrderHeader )SELECTSalesOrderID, OrderDate, RowNumberFROM...
Only the most recent CU that was released for SQL Server 2017 is available at the Download Center. CU packages for Linux are available at https://packages.microsoft.com/. Note Each new CU contains all the fixes that were included with the previous CU for the installed version of SQL Server...