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SQL standard to escape column names?
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For MySQL, use back ticks `.
For instance:
SELECT `column`, `column2` FROM `table`
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What's the difference between NOT EXISTS vs. NOT IN vs. LEFT JOIN WHERE IS NULL?
... using Standard SQL.
An obvious omission is the equivalent using EXCEPT:
SELECT a FROM table1
EXCEPT
SELECT a FROM table2
Note in Oracle you need to use the MINUS operator (arguably a better name):
SELECT a FROM table1
MINUS
SELECT a FROM table2
Speaking of proprietary syntax, there may also ...
Right query to get the current number of connections in a PostgreSQL DB
...ires aren't equivalent. The equivalent version of the first one would be:
SELECT sum(numbackends) FROM pg_stat_database;
In that case, I would expect that version to be slightly faster than the second one, simply because it has fewer rows to count. But you are not likely going to be able to measu...
How to delete a row by reference in data.table?
...el.idxs' vs. 'keep.idxs'
keep.idxs <- setdiff(DT[, .I], del.idxs); # select row indexes to keep
cols = names(DT);
DT.subset <- data.table(DT[[1]][keep.idxs]); # this is the subsetted table
setnames(DT.subset, cols[1]);
for (col in cols[2:length(cols)]) {
DT.subset[, (col) := DT[...
Regular expression to match DNS hostname or IP Address?
...check separately that the total length of the hostname must not exceed 255 characters. For more information, please consult RFC-952 and RFC-1123.
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How do I get my solution in Visual Studio back online in TFS?
...t-click on the solution name right at the top of the Solution Explorer and select the Go Online option. Clicking this allowed me to select the files that had been changed when I was offline and make the solution online again.
After finding the solution, I found the following msdn forum thread which...
Access denied for user 'root'@'localhost' while attempting to grant privileges. How do I grant privi
...here ...
Now, what's missing then ?
On my system, I get this:
mysql> select version();
+------------+
| version() |
+------------+
| 5.5.21-log |
+------------+
1 row in set (0.00 sec)
mysql> SHOW GRANTS FOR 'root'@'localhost';
+------------------------------------------------------------...
OSX - How to auto Close Terminal window after the “exit” command executed.
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in Terminal.app
Preferences > Profiles > (Select a Profile) > Shell.
on 'When the shell exits' chosen 'Close the window'
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Coding in Other (Spoken) Languages
... @Jonik: At least you didn't have to argue about ASCII/extended charset. In some places (here), there used to be a large debate on naming your identifiers a) in English, b) in Czech without accents, c) in Czech with the accents (most of which you can't type without Czech keyboard layout, ...
IntelliJ shortcut to show a popup of methods in a class that can be searched
... the list or highlight the desired element. Press Enter to navigate to the selected element.
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