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https://issues.apache.org/jira/browse/IGNITE-4904?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16024830#comment-16024830
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Pavel Tupitsyn edited comment on IGNITE-4904 at 5/25/17 3:31 PM:
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Turns out {{DELETE FROM}} with joins is not supported by H2:
http://www.h2database.com/html/grammar.html#delete
The workaround is to use subquery ({{Contains}} in LINQ).
Examples of supported queries:
{code}
var persons = ignite.GetCache<int, Person>("persons").AsCacheQueryable();
persons.Where(x => x.Key > 10).RemoveAll();
persons.RemoveAll(x => x.Key > 10); // Exactly the same SQL as above
persons.Take(3).RemoveAll();
// Join workaround:
var orgs = ignite.GetCache<int, Organization>("orgs").AsCacheQueryable();
var orgIds = orgs.Where(x => x.Value.Name == "foo").Select(x => x.Key);
persons.Where(x => orgIds.Contains(x.Value.OrgId)).RemoveAll(); // Generates
_key IN (select ...)
{code}
was (Author: ptupitsyn):
Turns out {{DELETE FROM}} with joins is not supported by H2:
http://www.h2database.com/html/grammar.html#delete
The workaround is to use subquery ({{Contains}} in LINQ).
Examples of supported queries:
{code}
var persons = ignite.GetCache<int, Person>("persons").AsCacheQueryable();
persons.Where(x => x.Key > 10).RemoveAll();
persons.RemoveAll(x => x.Key > 10); // Exactly the same SQL as above
// Join workaround:
var orgs = ignite.GetCache<int, Organization>("orgs").AsCacheQueryable();
var orgIds = orgs.Where(x => x.Value.Name == "foo").Select(x => x.Key);
persons.Where(x => orgIds.Contains(x.Value.OrgId)).RemoveAll(); // Generates
_key IN (select ...)
{code}
> .NET: DML via LINQ
> ------------------
>
> Key: IGNITE-4904
> URL: https://issues.apache.org/jira/browse/IGNITE-4904
> Project: Ignite
> Issue Type: New Feature
> Components: platforms
> Affects Versions: 1.9
> Reporter: Pavel Tupitsyn
> Assignee: Pavel Tupitsyn
> Labels: .NET, LINQ
> Fix For: 2.1
>
>
> Perform bulk update operations via LINQ: {{UPDATE WHERE}}, {{DELETE WHERE}}.
> Insert can already be done on object level with {{ICache.PutAll}}.
> 1) {{DELETE WHERE}}. This is quite simple. We can provide an extension method
> like this:
> {code}
> public static int DeleteAll<K, V>(this ICache<K, V> cache,
> IQueryable<ICacheEntry<K, V>> items);
> {code}
> 2) {{UPDATE WHERE}}. This is tricky, because LINQ only works with expression
> trees, and multi-line methods are not supported. We should come up with a way
> to provide a list of columns and values, something like
> {code}
> public static int UpdateAll<K, V>(this ICache<K, V> cache,
> IQueryable<ICacheEntry<K, V>> items, params UpdateAction[] actions);
> {code}
> where UpdateAction can consist of a MemberExpression and a value for that
> member.
> We should probably do delete as a separate task first.
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