Linq查询而不是包含运算符的性能问题 [英] Linq Query instead of Contains Operator for Performance issue

问题描述

我必须提取所有ID在列表中的客户

I have to Pull all customers whose ids are in the list

我有一个CustomerID的列表

I have a list of CustomerID`s

列表custidlist =新列表{1,2,3 .... etc.}();

我必须编写一个linq查询来获取所有ID在上面列表中的客户

i have to write a linq query to get all customers whose id`s are in the above list

客户列表.

var customer = db.Customers.Where(c => custidlist.包含(c.customerid));

var customers=db.Customers.Where(c=> custidlist.Contains(c.customerid));

在性能问题上使用包含不好.

Using Contains is not good in performance issue.

我们可以像这样使用COMPARE运算符

Can we use COMPARE OPERATOR LIKE THIS

var customer = db.Customers.Where(c => custidlist. Compare (c.customerid)); ????

var customers=db.Customers.Where(c=> custidlist.Compare(c.customerid)); ????

I Heard Compare最适合性能

I Heard Compare is best for Performance

推荐答案

由于这是Linq to SQL/实体，因此您的Linq Contains查询将被转换为类似于以下内容的SQL语句:

Since this is Linq to SQL / Entities your Linq Contains query will be translated to a SQL statement roughly like:

select * from Customers where customerId in (1,2,3)

不仅不支持您的其他建议，而且您在此SQL性能方面做得更好.

Not only is your other suggestion not supported, but also you cannot do any better than this SQL performance wise.

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