大约有 47,000 项符合查询结果（耗时：0.0387秒） [XML]
Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '=
...:
SET @rUsername = ‘aname’ COLLATE utf8_unicode_ci; -- COLLATE added
CALL updateProductUsers(@rUsername, @rProductID, @rPerm);
Option 2: add COLLATE to the WHERE clause:
CREATE PROCEDURE updateProductUsers(
IN rUsername VARCHAR(24),
IN rProductID INT UNSIGNED,
IN rPerm VARCHAR(16...
What is 'Pattern Matching' in functional languages?
...wesome.
Algebraic data types in a nutshell
ML-like functional languages allow you define simple data types called "disjoint unions" or "algebraic data types". These data structures are simple containers, and can be recursively defined. For example:
type 'a list =
| Nil
| Cons of 'a * 'a ...
serve current directory from command line
...also running on a Mac. Tried it with Ruby 1.8.7, 1.9.3 and 2.0.0, and they all work. Weird.
– Daniel Perez Alvarez
Sep 9 '13 at 9:04
7
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How to generate keyboard events in Python?
...om ctypes import wintypes
import time
user32 = ctypes.WinDLL('user32', use_last_error=True)
INPUT_MOUSE = 0
INPUT_KEYBOARD = 1
INPUT_HARDWARE = 2
KEYEVENTF_EXTENDEDKEY = 0x0001
KEYEVENTF_KEYUP = 0x0002
KEYEVENTF_UNICODE = 0x0004
KEYEVENTF_SCANCODE = 0x0008
MAPVK_VK_TO_VSC = 0
# ...
Should switch statements always contain a default clause?
...e back), I was told that it's good practice to include a default clause in all switch statements. I recently remembered this advice but can't remember what the justification was. It sounds fairly odd to me now.
...
Changing Font Size For UITableView Section Headers
...wForHeaderInSection:(NSInteger)section {
UILabel *myLabel = [[UILabel alloc] init];
myLabel.frame = CGRectMake(20, 8, 320, 20);
myLabel.font = [UIFont boldSystemFontOfSize:18];
myLabel.text = [self tableView:tableView titleForHeaderInSection:section];
UIView *headerView = [[UIV...
Split array into chunks
...
Nope, the last chunk should just be smaller than the others.
– Blazemonger
Jul 22 '14 at 23:27
7
...
Real world use cases of bitwise operators [closed]
...checksums, parity, stop bits, flow control algorithms, and so on, which usually depend on the logic values of individual bytes as opposed to numeric values, since the medium may only be capable of transmitting one bit at a time.
Compression, Encryption
Both of these are heavily dependent on bitwise ...
Map over object preserving keys
...
With Underscore
Underscore provides a function _.mapObject to map the values and preserve the keys.
_.mapObject({ one: 1, two: 2, three: 3 }, function (v) { return v * 3; });
// => { one: 3, two: 6, three: 9 }
DEMO
With Lodash
Lodash provides a function _.mapVa...
how do you filter pandas dataframes by multiple columns
...r function using query in pandas. Here you have filtering of df results by all the kwargs parameters. Dont' forgot to add some validators(kwargs filtering) to get filter function for your own df.
def filter(df, **kwargs):
query_list = []
for key in kwargs.keys():
query_list.append(f...