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Hibernate: hbm2ddl.auto=update in production?
...l, such as pushing the length of a String column up over 255 and seeing it convert to text, mediumtext, etc etc.
Granted, I don't think there is really a way to "convert datatypes" with without creating a new column, copying the data and blowing away the old column. But the minute your database ha...
How to create a MySQL hierarchical recursive query
... (select @pv := '19') initialisation
where find_in_set(parent_id, @pv)
and length(@pv := concat(@pv, ',', id))
Here is a fiddle.
Here, the value specified in @pv := '19' should be set to the id of the parent you want to select all the descendants of.
This will work also if a parent has m...
What is the difference between quiet NaN and signaling NaN?
I have read about floating-point and I understand that NaN could result from operations. But I can't understand what these are concepts exactly. What is the difference between them?
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Get path of executable
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@curiousguy I'm not sure I understand you; I'm pretty sure that's the whole point of this question :)
– Ben Hymers
Dec 8 '11 at 22:08
6
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Group by multiple columns in dplyr, using string vector input
...orm(100)
)
# Columns you want to group by
grp_cols <- names(df)[-3]
# Convert character vector to list of symbols
dots <- lapply(grp_cols, as.symbol)
# Perform frequency counts
df %>%
group_by_(.dots=dots) %>%
summarise(n = n())
output:
Source: local data frame [9 x 3]
Grou...
Test whether string is a valid integer
...l script. If the user provided a valid integer, the script does one thing, and if not valid, it does something else. Trouble is, I haven't found an easy (and reasonably elegant) way of doing this - I don't want to have to pick it apart char by char.
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How to DROP multiple columns with a single ALTER TABLE statement in SQL Server?
I would like to write a single SQL command to drop multiple columns from a single table in one ALTER TABLE statement.
11 ...
How can I limit Parallel.ForEach?
...new ParallelOptions { MaxDegreeOfParallelism = Convert.ToInt32(Math.Ceiling((Environment.ProcessorCount * 0.75) * 1.0)) };
– jKlaus
Dec 2 '15 at 18:18
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Why does Sql Server keep executing after raiserror when xact_abort is on?
...tion error - it's not.
Your workaround is just about what you need to do, and using an explicit transaction doesn't have any effect on the behavior you want to change.
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stdlib and colored output in C
...which requires colored output. How can I make my output colored like emacs and bash do?
7 Answers
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