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What does ON [PRIMARY] mean?
... drive D:\ of your server. you could then create another filegroup called Indexes. This filegroup could reside on drive E:\ of your server.
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Bogus foreign key constraint fail
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On demand, now as an answer...
When using MySQL Query Browser or phpMyAdmin, it appears that a new connection is opened for each query (bugs.mysql.com/bug.php?id=8280), making it neccessary to write all the drop statements in one query, eg.
SET FOREIGN_KEY_CHECKS=0;
DROP TABLE my_first_...
“git rm --cached x” vs “git reset head -- x”?
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There are three places where a file, say, can be - the tree, the index and the working copy. When you just add a file to a folder, you are adding it to the working copy.
When you do something like git add file you add it to the index. And when you commit it, you add it to the tree as well...
Find MongoDB records where array field is not empty
...ind({ pictures: { $exists: true, $not: {$size: 0} } })
MongoDB don't use indexes if $size is involved, so here is a better solution:
ME.find({ pictures: { $exists: true, $ne: [] } })
Since MongoDB 2.6 release, you can compare with the operator $gt but could lead to unexpected results (you can f...
How to remove item from list in C#?
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List<T> has two methods you can use.
RemoveAt(int index) can be used if you know the index of the item. For example:
resultlist.RemoveAt(1);
Or you can use Remove(T item):
var itemToRemove = resultlist.Single(r => r.Id == 2);
resultList.Remove(itemToRemove);
When yo...
How to check whether a pandas DataFrame is empty?
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I use the len function. It's much faster than empty. len(df.index) is even faster.
import pandas as pd
import numpy as np
df = pd.DataFrame(np.random.randn(10000, 4), columns=list('ABCD'))
def empty(df):
return df.empty
def lenz(df):
return len(df) == 0
def lenzi(df):
...
How to allow to accept only image files?
...ttp://www.w3schools.com/tags/att_input_accept.asp
http://www.w3schools.com/php/php_file_upload.asp
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ssl证书申请报错:challenge = [c for c in authorization[\'challenges\']...
...ge = [c for c in authorization['challenges'] if c['type'] == "http-01"][0] IndexError: list index out of rangechallenge-list-index-out-of-range使用acme-tiny申请ssl证书时报错:challenge = [c for c in authorization[& 39;challenges& 39;] if c[& 39;type& 39;] == "http-01"][0] IndexError: list ...
mysql实现split分割字符串(length, SUBSTRING_INDEX, substring) - 爬虫/...
由于MySql没有直接的split函数,只提供了length, SUBSTRING_INDEX, substring三个函数,这里介绍如何用这三个函数实现split功能。
# SUBSTRING_INDEX(str, delim, count):返回字符串 str 中在第 count 个出现的分隔符 delim 之前的子串。如果 count 是...
How can I index a MATLAB array returned by a function without first assigning it to a local variable
...ssible to do what you want, but you have to use the functional form of the indexing operator. When you perform an indexing operation using (), you are actually making a call to the subsref function. So, even though you can't do this:
value = magic(5)(3, 3);
You can do this:
value = subsref(magic...
