Get the total number of records when doing pagination
To get a page from a 开发者_StackOverflow社区database I have to execute something like this:
var cs = ( from x in base.EntityDataContext.Corporates
select x ).Skip( 10 ).Take( 10 );
This will skip the first 10 rows and will select the next 10.
How can I know how many rows would result because of the query without pagination? I do not want to run another query to get the count.
To get the total number of records before skip/take you have to run a separate query. Getting the actual number returned would use Count(), but wouldn't result in another query if the original query was materialized.
var q = from x in base.EntityDataContext.Corporates
select x;
var total = q.Count();
var cs = q.Skip(10).Take(10);
var numberOnSelectedPage = cs.Count();
Bottom line: you have to run two queries. You simply can't get around it.
Here's a good way to do it, however, that caches the original LINQ query and filter, making for less copy/paste errors:
var qry = from x in base.EntityDataContext.Coporates select x;
var count = qry.Count();
var items = qry.Skip(10).Take(10).ToList();
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