NOT IN会多次扫描表,使用EXISTS、NOT EXISTS ,IN , LEFT OUTER JOIN 来替代,特别是左连接,而Exists比IN更快,最慢的是NOT操作.如果列的值含有空,以前它的索引不起作用,现在2000的优化器能够处理了。相同的是IS NULL,“NOT", "NOT EXISTS", "NOT IN"能优化她,而”<>”等还是不能优化,用不到索引。 23...
I have tried to start a SQL script editor where I have written: CREATE PROCEDURE CountProducts () BEGIN SELECT COUNT(*) AS ANTAL FROM product; END I think it is correct, but I cant see any stored procedure being created (as a icon or something else) like in SQL server. Am...
// This procedure shows how pass a value to a TVP to a stored procedure // using a List<SqlDataRecord>. private static void list_example() { // Our sample input data. int[] products = {9, 12, 27, 37}; // Here we use a List<SqlDataRecord>. SqlDataRecord is the namespace /...
from p in db.Products select new { p.ProductID, HalfPrice = p.UnitPrice / 2 }; 上面语句描述:使用SELECT和匿名类型返回所有产品的ID以及 HalfPrice(设置为产品单价除以2所得的值)的序列。 3.条件形式: 说明:生成SQL语句为:case when condition then else。 var q = from p in db.Products select ...
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Thank you for posting in Windows Server Forum.Are you talking about RemoteApp RDP files which is stored under that part? In server 2012\R2Now the RemoteApp RDP file and RemoteDesktop files are stored under following path. C:\Windows\RemotePackages\RemoteApps...
you can useISNULL.You also can useCASE.CASEfunction is equivalent to theCOALESCEfunction in SQL Server. It evaluates a list of conditions and returns one result expression from multiple possible result expressions. If you do not want to use COALESCE or CASE function, you can use an alternative...
i caught in situation to create a stored procedure and provide the offset feature, that means i needed the pagination support in my stored procedure. There isno direct keywordavailable in SQL Server something like LIMIT in mysql. And therefore i thought to share my solution with community. So...
查询以仅提取与特定where条件相关或具有特定where条件数据的列注解是内联的。基本思想是：询问元数据表信息...
I am very frustrated with the behavior i am seeing from mySql today. I have always been able to accomplish my goal using this same technique in MS SQL server and Oracle. i would appreciate any help you guys can provide. It appears MySQL is evaluating both statements when using the OR ope...