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Hibernate throws MultipleBagFetchException - cannot simultaneously fetch multiple bags
...Many(mappedBy="parent", fetch=FetchType.EAGER)
@Fetch(value = FetchMode.SUBSELECT)
private List<Child> childs;
This should fix the issue, related to Hibernate bug HHH-1718
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What is the difference between IQueryable and IEnumerable?
...es, meaning the custom query logic it receives, e.g., a predicate or value selector, is in the form of an expression tree instead of a delegate to a method.
IEnumerable<T> is great for working with sequences that are iterated in-memory, but
IQueryable<T> allows for out-of memory things ...
Are database triggers evil? [closed]
...lumns wouldn't exist and you'd have to process a function on each row when selecting them. That's likely to kill DBMS performance, far better to create the auto-generated column at insert/update time since that's the only time it changes.
Also, lack of triggers would prevent data rules from being e...
Can't find a “not equal” css attribute selector
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One problem with the accepted answer is that it will also select elements that do not have a foo attribute at all. Consider:
<div>No foo</div>
<div foo="">Empty foo</div>
<div foo="x">XXX</div>
<div foo="y">YYY</div>
<div foo="z"&g...
Tricks to manage the available memory in an R session
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I make aggressive use of the subset parameter with selection of only the required variables when passing dataframes to the data= argument of regression functions. It does result in some errors if I forget to add variables to both the formula and the select= vector, but it sti...
Undoing a commit in TortoiseSVN
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Go to Show Log Screen, select the revision that you want to undo, right click it and select Revert changes from this revision, this will do a reverse-merge.
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How does a PreparedStatement avoid or prevent SQL injection?
...o in detail.
Compilation Phase:
In this phase, keywords used in query like select, from, where etc are converted into format
understandable by machine.
This is the phase where query is interpreted and corresponding action to be taken is decided.
It also has many other tasks to do, but let's not go ...
Visual Studio: Make view code default
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Right-click on a file and select "Open With..."
Select "CSharp Editor" and then click "Set as Default".
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What's the $unwind operator in MongoDB?
...oDB employs an "NoSQL" approach to data storage, so perish the thoughts of selects, joins, etc. from your mind. The way that it stores your data is in the form of documents and collections, which allows for a dynamic means of adding and obtaining the data from your storage locations.
That being sai...
How to change the CHARACTER SET (and COLLATION) throughout a database?
...re schema to utf8. Hope this helps!
-- Change DATABASE Default Collation
SELECT DISTINCT concat('ALTER DATABASE `', TABLE_SCHEMA, '` CHARACTER SET utf8 COLLATE utf8_unicode_ci;')
from information_schema.tables
where TABLE_SCHEMA like 'database_name';
-- Change TABLE Collation / Char Set
SELECT...