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mysql create user if not exists
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I use
SELECT EXISTS (SELECT DISTINCT user FROM mysql.user WHERE user = "username") as is_user
should return 1 if exists or 0 if it does not
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Repeat each row of data.frame the number of times specified in a column
...es
library(dplyr)
df %>%
slice(rep(seq_len(n()), freq)) %>%
select(-freq)
# var1 var2
#1 a d
#2 b e
#3 b e
#4 c f
#5 c f
#6 c f
seq_len(n()) part can be replaced with any of the following.
df %>% slice(rep(1:nrow(df), freq)) %>% select(-...
Is there a way to find/replace across an entire project in Eclipse?
...en go right-click on the project and do search from there (then make sure "selected resource" is selected in the dialog box).
– Travitron
Apr 27 '12 at 11:22
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How to undo “git commit --amend” done instead of “git commit”
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additionally, this answer allows you to selectively pick the changes that you accidentally 'amended', to does provide some additional value to the git reset --soft HEAD@{1} approach (which did solve my problem BTW)
– Wiebe Tijsma
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Is there a better way to express nested namespaces in C++ within the header
...A_HELPER_EXPAND(VA_COUNT_HELPER(__VA_ARGS__, 6, 5, 4, 3, 2, 1))
#define VA_SELECT_CAT(_Name, _Count, ...) VA_HELPER_EXPAND(_Name##_Count(__VA_ARGS__))
#define VA_SELECT_HELPER(_Name, _Count, ...) VA_SELECT_CAT(_Name, _Count, __VA_ARGS__)
#define VA_SELECT(_Name, ...) VA_SE...
Convert seconds to Hour:Minute:Second
...ed to that of the TIME data type, which is from -838:59:59 to 838:59:59 :
SELECT SEC_TO_TIME(8525);
# 02:22:05
See: SEC_TO_TIME
Run the Demo
PostgreSQL example:
SELECT TO_CHAR('8525 second'::interval, 'HH24:MI:SS');
# 02:22:05
Run the Demo
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SQLite add Primary Key
...Sqlite by using the CREATE TABLE AS syntax to create a table based on a SELECT statement. Now this table has no primary key but I would like to add one.
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Linq list of lists to single list
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You want to use the SelectMany extension method.
var residences = details.SelectMany(d => d.AppForm_Residences).ToList();
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Get Folder Size from Windows Command Line
...mmand "$fso = new-object -com Scripting.FileSystemObject; gci -Directory | select @{l='Size'; e={$fso.GetFolder($_.FullName).Size}},FullName | sort Size -Descending | ft @{l='Size [MB]'; e={'{0:N2} ' -f ($_.Size / 1MB)}},FullName"
Same but Powershell only:
$fso = new-object -com Scripting.File...
Add a method breakpoint to all methods of a class in EclipseIDE
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The fastest way is to go to the "Outline" view and select all of the methods you want, right-click and click "Toggle Method Breakpoint"
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