The Case-When-Exists expression in Oracle is really handy. Here's an example of how to use it in a sub-select to return a status. This SQL checks for a match between thePS_PERSONandPSOPRDEFNrecords to determine the person status. The idea is that if the operator is not inPS_PERSONth...
4、保存即可生成视图,即相当于全联接的SQl语句。 14.存储过程 1)优点:在创建时进行编译,以后每次执行存储过程不需要再编译,而一般的SQL语句要每执行一次编译一次(所以一些复杂逻辑的SQL建议写在存储过程里面);存储过程过重复使用,可减少数据库开发人员的工作量(所以一些经常被调用到的SQL建议写在存储过程里面);安全...
我做错了什么并出错。 我的SQL 语句就像DECLARE @AreaId INT = 2 DECLARE @Areas Table(AreaId int) INSERT INTO @Areas SELECT AreaId FROM AreaMaster WHERE CityZoneId IN (SELECT CityZoneId FROM AreaMaster WHERE AreaId = @AreaID) SELECT * FROM dbo.CompanyMaster WHERE AreaId IN (CASE WHEN EX...
下面的附件中,关于case when 、 in 、not in 、exists 、not exists的例子,以及in和exists之间的区别,我也是在网上找的例子,在这里分享一下,用到的时候可以参考一下。
THEN'Store Contact'-- Check for individual consumerWHENEXISTS(SELECT*FROMSales.IndividualASiWHEREi.ContactID = @ContactID)THEN'Consumer'END;-- Return the information to the callerIF @ContactID IS NOT NULLBEGININSERT@retContactInformationSELECT@ContactID, @FirstName, @LastName, @ContactType;END; ...
SQL WITHData(value)AS(SELECT0UNIONALLSELECT1)SELECTCASEWHENMIN(value) <=0THEN0WHENMAX(1/value) >=100THEN1ENDFROMData; GO 針對純量運算式 (包括傳回純量的非相互關聯子查詢,而非針對彙總運算式),您應該僅相依於 WHEN 條件的評估順序。 您也必須確定 THEN 或 ELSE 子句中至少有一個運算式不是 NULL...
模拟IF WHILE EXISTS CASE 表达式 SQL_VARIANT 列 事务 管理,包括内存不足 性能,包括统计信息 使用SSMS 实现内存优化 分区 计划指南 查询存储 查询优化助手 Resource Governor 统计信息 查询数据 报告和分析 安全性 工具 教程 Linux 上的 SQL Server Azure 上的 SQL ...
To multiply the sales amount from 'Los Angeles' by 2 and the sales amount from 'San Diego' by 1.5 while keeping the sales amount for other stores the same, we would use the following SQL statement using CASE: SELECT Store_Name, CASE Store_Name WHEN 'Los Angeles' THEN Sales * 2 WHEN...
When the aggregated field name is set to a field that exists on the model of the queryset (i.e. is not annotated), the aggregation works. For example: instead of using cost_value=None in the When() of the aggregators, using quantity=None works. Similarly, doing an aggregation over an...
When we tried to create databases and tables in uppercase, it created those in lowercase only. Creation of #table1_test2 failed with error already exists, since the first created statement of #Table1_test2 was converted into lowercase and created table #table1_test2. The same happened when ...