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postgresql - sql - count of `true` values
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In MySQL, you can do this as well:
SELECT count(*) AS total
, sum(myCol) AS countTrue --yes, you can add TRUEs as TRUE=1 and FALSE=0 !!
FROM yourTable
;
I think that in Postgres, this works:
SELECT count(*) AS total
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Log4net rolling daily filename with date in the file name
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To preserve file extension:
<log4net>
<root>
<level value="DEBUG"/>
<appender-ref ref="RollingLogFileAppender"/>
</root>
<appender name="RollingLogFileAppender" type="log4net.Appender.RollingFileAppender">
<f...
How to open every file in a folder?
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you should try using os.walk
yourpath = 'path'
import os
for root, dirs, files in os.walk(yourpath, topdown=False):
for name in files:
print(os.path.join(root, name))
stuff
for name in dirs:
print(os.path.join(root, name))
stuff
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How to get multiple counts with one SQL query?
... entire nested query with a simple count(*) as @Mihai shows - with further MySQL only syntax simplifications.
– YoYo
Apr 1 '17 at 19:29
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Setting up foreign keys in phpMyAdmin?
...dmin lets you define foreign keys using their "relations" view. But since, MySQL only supports foreign constraints on "INNO DB" tables, the first step is to make sure the tables you are using are of that type.
To setup a foreign key so that the PID column in a table named CHILD references the ID co...
TCP 的那些事儿（下） - 更多技术 - 清泛网 - 专注C/C++及内核技术
...情况太糟糕，反应也很强烈。
sshthresh = cwnd /2
cwnd 重置为 1
进入慢启动过程
2）Fast Retransmit算法，也就是在收到3个duplicate ACK时就开启重传，而不用等到RTO超时。
TCP Tahoe的实现和RTO超时一样。
TCP Reno的...
App restarts rather than resumes
...l Activity. If those two flags are present and the Activity is not at the root of the task (meaning the app was already running), then I call finish() on the initial Activity. That exact solution may not work for you, but something similar should.
Here is what I do in onCreate() of the initial/l...
How to work around the lack of transactions in MongoDB?
...chnology applied to Mongodb try github.com/Tokutek/mongo , if you need the mysql version maybe they added it to their standard version of Mysql that they usually provide with
– Giovanni Bitliner
Dec 8 '15 at 8:57
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How can I remove a pytz timezone from a datetime object?
...Datetime.replace(tzinfo=None)
Why would you do this? One example is that mysql does not support timezones with its DATETIME type. So using ORM's like sqlalchemy will simply remove the timezone when you give it a datetime.datetime object to insert into the database. The solution is to convert your ...
How to find list of possible words from a letter matrix [Boggle Solver]
...value) - 97] = self
def MakeTrie(dictfile):
dict = open(dictfile)
root = TrieNode(None, '')
for word in dict:
curNode = root
for letter in word.lower():
if 97 <= ord(letter) < 123:
nextNode = curNode.children[ord(letter) - 97]
...