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SqlException from Entity Framework - New transaction is not allowed because there are other threads
...for performance for large datasets? If you have a millions records in the table. ToList() will suck them all into memory. I'm running into this very problem and was wondering whether the following would be feasible a)Detach the entity b)Create a new ObjectContext and attach the detached entity to i...
How to make a transparent UIWebView
I have an app with a UITableView and a corresponding detail view for each row. In the detail view I have to display some text and a background image (text is different for each row, but the image remains the same). The easiest way, in my opinion, is to put the text in an .rtf file and display it i...
Group by with multiple columns using lambda
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@Jacob - Anonymous types are immutable classes with properly overriden GetHashCode & Equals methods. They where designed for exactly this kind of use case.
– Enigmativity
Aug 4 '11 at 2:57
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Best way to store time (hh:mm) in a database
I want to store times in a database table but only need to store the hours and minutes.
I know I could just use DATETIME and ignore the other components of the date, but what's the best way to do this without storing more info than I actually need?
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delete_all vs destroy_all?
I am looking for the best approach to delete records from a table. For instance, I have a user whose user ID is across many tables. I want to delete this user and every record that has his ID in all tables.
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What is the difference between tinyint, smallint, mediumint, bigint and int in MySQL?
... take up different amounts of space and they have different ranges of acceptable values.
Here are the sizes and ranges of values for SQL Server, other RDBMSes have similar documentation:
MySQL
Postgres
Oracle (they just have a NUMBER datatype really)
DB2
Turns out they all use the same specific...
Laravel 4 Eloquent Query Using WHERE with OR AND OR?
...', '=', $d);
})->get();
Will produce a query like:
SELECT * FROM <table> WHERE (a='foo' or b='bar') AND (c='john' or d='doe');
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What's the difference between equal?, eql?, ===, and ==?
...programming languages, such as Ruby, provide a collection type called hash table. Hash tables are dictionary-like collections which store data in pairs, consisting of unique keys and their corresponding values. Under the hood, those keys are stored as hashcodes. Hash tables are commonly referred to ...
Awk学习笔记 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...置函数
控制流命令
4. awk的环境变量
Table 1. awk的环境变量
变量
描述
$n
当前记录的第n个字段，字段间由FS分隔。
$0
完整的输入记录。
ARGC
命令行参数的数目。
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Get last record in a queryset
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Django Doc:
latest(field_name=None) returns the latest object in the table, by date, using the field_name provided as the date field.
This example returns the latest Entry in the table, according to the
pub_date field:
Entry.objects.latest('pub_date')
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