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Why does calling a method in my derived class call the base class method?
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You can imagine, that a class, when instantiated, is nothing more than a table of pointers, pointing to the actual implementation of its methods. The following image should visualize this pretty well:
Now there are different ways, a method can be defined. Each behaves different when it is used ...
Is it possible to break a long line to multiple lines in Python [duplicate]
...t a list of strings instead of one long string:
queryText= "SELECT * FROM TABLE1 AS T1"\
"JOIN TABLE2 AS T2 ON T1.SOMETHING = T2.SOMETHING"\
"JOIN TABLE3 AS T3 ON T3.SOMETHING = T2.SOMETHING"\
"WHERE SOMETHING BETWEEN <WHATEVER> AND <WHATEVER ELSE>"\
"ORDER BY WHATEVERS DESC"
kinda li...
Shortcuts in Objective-C to concatenate NSStrings
...ly as pleasant as just having a concatenation operator.
First, use an NSMutableString, which has an appendString method, removing some of the need for extra temp strings.
Second, use an NSArray to concatenate via the componentsJoinedByString method.
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How do you manually execute SQL commands in Ruby On Rails using NuoDB
...n.execute("foo")
with "foo" being the sql statement( i.e. "SELECT * FROM table").
This command will return a set of values as a hash and put them into the results variable.
So on my rails application_controller.rb I added this:
def execute_statement(sql)
results = ActiveRecord::Base.connectio...
Is it a good idea to index datetime field in mysql?
.... In my application I will have many rows for example I currently have one table with 4 million records. Most of my queries use datetime clause to select data. Is it a good idea to index datetime fields in mysql database?
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SQL Server IN vs. EXISTS Performance
... test case does not mean that the optimizer will do the exact same plan on tables with different statistics. This might lead someone to think the answer is partial - but the nonexistence of multiple semijoin operators is fact. Maybe I'll find a list somewhere and link it.
– Geo...
Order Bars in ggplot2 bar graph
...y axis and the shortest bar would be furthest. So this is kind of like the Table I have
14 Answers
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can we use xpath with BeautifulSoup?
...formbody')
for elem in td_empformbody(tree):
# Do something with these table cells.
Coming full circle: BeautifulSoup itself does have very complete CSS selector support:
for cell in soup.select('table#foobar td.empformbody'):
# Do something with these table cells.
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Subset of rows containing NA (missing) values in a chosen column of a data frame
...t "NA" strings to NA values, and let "NULL" strings as is).
If using read.table() or read.csv(), you should consider the "na.strings" argument to do clean data import, and always work with real R NA values.
An example, working in both cases "NULL" and "NA" cells :
DF <- read.csv("file.csv", na...
How to get UITableView from UITableViewCell?
I have a UITableViewCell which is linked to an object and I need to tell if the cell is visible. From the research I've done, this means I need to somehow access the UITableView that contains it (from there, there are several ways to check if it's visible). So I'm wondering if UITableViewCell ...