大约有 37,000 项符合查询结果（耗时：0.0468秒） [XML]
The relationship could not be changed because one or more of the foreign-key properties is non-nulla
...ing this issue is because of how you've set your primary key in your child table. It should be composite, but it's not. So, Entity Framework sees this association as aggregation, which means, when you remove or clear the child objects, it's not going to delete the child records. It'll simply remove ...
How to work around the lack of transactions in MongoDB?
...is that, in a relational database, we need to make changes across multiple tables. Usually tables that need to be joined and so we want to do that all at once. And to do it, since there are multiple tables, we'll have to begin a transaction and do all those updates and then end the transaction. But ...
What is Lazy Loading?
...ded.
I.e. suppose you needed to have a record which has a join of several tables. If you fetched it all at once it would take longer than if you would fetch say only the main table. Using lazy-loading the rest of the information will be fetched only if it is needed. So it is actually 'efficient-loa...
Execute raw SQL using Doctrine 2
...e your query and fetchAll:
$result= $conn->query('select foobar from mytable')->fetchAll();
Get the data out of result like this:
$this->appendStringToFile("first row foobar is: " . $result[0]['foobar']);
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How to use HTML to print header and footer on every printed page of a document?
...oters in print media.
And while you might be able to simulate it with:
tables
fixed position blocks
they each have bugs that prevent them from being the ideal general solution.
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How to find out what character key is pressed?
...
Try:
<table>
<tr><td>Key:</td><td id="key"></td></tr>
<tr><td>Key Code:</td><td id="keyCode"></td></tr>
<tr><td>Event Code:</td><td ...
Can you add new statements to Python's syntax?
..... this can't be good. So what went wrong?
The case of the missing symbol table
One of the steps the Python compiler performs when compiling the AST is create a symbol table for the code it compiles. The call to PySymtable_Build in PyAST_Compile calls into the symbol table module (Python/symtable....
Architecture for merging multiple user accounts together
...an account membership entry in your database somewhat like this
Table = Users
[ UserId | Email | Password ]
[ 23 | "newuser@coolmail.com" | *null* ]
3) create an external auths entry like so
*ProviderUserId is the unique id of...
Determine whether an array contains a value [duplicate]
...oject and nowadays it's Babel :) big win for JavaScript community! There's table of what's available of ES7 already on many platforms including babel pollyfils kangax.github.io/compat-table/es2016plus
– Lukas Liesis
Jul 12 '16 at 9:52
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Can my enums have friendly names? [duplicate]
...C++ compiler may emit an if/else if chain, I think it can also emit a jump table if the compiler deems it appropriate. For instance, if you're switching off of a byte value, I think it will most likely just emit a jump table.
– reirab
Sep 5 '13 at 20:57
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