大约有 43,000 项符合查询结果（耗时：0.0580秒） [XML]
Linq code to select one item
...ion methods directly like:
var item = Items.First(i => i.Id == 123);
And if you don't want to throw an error if the list is empty, use FirstOrDefault which returns the default value for the element type (null for reference types):
var item = Items.FirstOrDefault(i => i.Id == 123);
if (ite...
Best way to get InnerXml of an XElement?
...would ever be more efficient in these conditions because of the penalty of converting a large list to a large array (even obvious here with smaller lists).
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In C#, how to instantiate a passed generic type inside a method?
...been writing C# for years with some heavy generic typing abuse in my days, and I NEVER knew you could define a constraint like this to instantiate a generic type. Many thanks!
– Nicolas Martel
Jan 2 '18 at 19:33
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postgresql list and order tables by size
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This will be more clear.
pg_size_pretty(<numeric_value>) - converts no.of bytes to human-readable format.
pg_database_size(<db_name>) - gets database size in bytes.
pg_total_relation_size(<relation_name>) - gets total size of table and its index in bytes.
pg_relation_s...
When should I use a struct rather than a class in C#?
When should you use struct and not class in C#? My conceptual model is that structs are used in times when the item is merely a collection of value types . A way to logically hold them all together into a cohesive whole.
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Create the perfect JPA entity [closed]
I've been working with JPA (implementation Hibernate) for some time now and each time I need to create entities I find myself struggling with issues as AccessType, immutable properties, equals/hashCode, ... .
So I decided to try and find out the general best practice for each issue and write this ...
How to write a simple database engine [closed]
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assume you have a table, with some data, we would create a data format to convert this table into a binary file, by agreeing on the definition of a column delimiter and a row delimiter and make sure such pattern of delimiter is never used in your data itself. i.e. if you have selected <*> for...
“where 1=1” statement [duplicate]
... SQL Injection possible. The security issue would be to use $cond (without converting it to an integer) to specify the minimum age in the query, and to check if isset($_REQUEST['cond']) is actually true (otherwise using 1 = 1).
– Arseni Mourzenko
Nov 16 '11 at ...
How to create dictionary and add key–value pairs dynamically?
...es will be coerced to a string when used as a key. E.g. a Date object gets converted to its string representation:
dict[new Date] = "today's value";
console.log(dict);
// => {
// "Sat Nov 04 2016 16:15:31 GMT-0700 (PDT)": "today's value"
// }
Note however that this doesn't necessarily...
Unable to find specific subclass of NSManagedObject
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Seems like Apple forgot to fully convert it to the swift .. dont know why but this fixed it for me pretty gently
– Jiří Zahálka
Nov 30 '14 at 0:32
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