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Add Foreign Key to existing table
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To add a foreign key (grade_id) to an existing table (users), follow the following steps:
ALTER TABLE users ADD grade_id SMALLINT UNSIGNED NOT NULL DEFAULT 0;
ALTER TABLE users ADD CONSTRAINT fk_grade_id FOREIGN KEY (grade_id) REFERENCES grades(id);
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Are PHP short tags acceptable to use?
...t). As you say, lots of shared hosts do support shorttags but "lots" isn't all of them. If you want to share your scripts, it's best to use the full syntax.
I agree that <? and <?= are easier on programmers than <?php and <?php echo but it is possible to do a bulk find-and-replace as lo...
Why do you have to link the math library in C?
...es libm, so if you compile a C++ program with GCC (g++), you will automatically get libm linked in.
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What is the difference between an expression and a statement in Python?
...s, where operators include arithmetic and boolean operators, the function call operator () the subscription operator [] and similar, and can be reduced to some kind of "value", which can be any Python object. Examples:
3 + 5
map(lambda x: x*x, range(10))
[a.x for a in some_iterable]
yield 7
Stat...
Set Focus on EditText
... set an OnFocusChangeListener for it. When it has lost focus, a method is called, which checks the value of the EditText with one in the database. If the return-value of the method is true, a toast is shown and the focus should get back on the EditText again. The focus should always get back on the ...
MySQL query to get column names?
I'd like to get all of a mysql table's col names into an array in php?
21 Answers
21
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instantiate a class from a variable in PHP?
...you work with namespace, put the current namespace into the string: $var = __NAMESPACE__ . '\\' . $var . 'Class';
– bastey
Sep 2 '13 at 13:28
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How to download image using requests
...flate). You can force it to decompress for you anyway by setting the decode_content attribute to True (requests sets it to False to control decoding itself). You can then use shutil.copyfileobj() to have Python stream the data to a file object:
import requests
import shutil
r = requests.get(settin...
How to join int[] to a character separated string in .NET?
...formance. Join method needs to know the size of the data to effectively preallocate necessary amount of memory.
Here is a part of internal implementation of String.Join method:
// length computed from length of items in input array and length of separator
string str = FastAllocateString(length);
f...
The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead [dupl
...hy is this happening?
The entire ext/mysql PHP extension, which provides all functions named with the prefix mysql_, was officially deprecated in PHP v5.5.0 and removed in PHP v7.
It was originally introduced in PHP v2.0 (November 1997) for MySQL v3.20, and no new features have been added since 2...