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Change type of varchar field to integer: “cannot be cast automatically to type integer”
I have a small table and a certain field contains the type " character varying ". I'm trying to change it to " Integer " but it gives an error that casting is not possible.
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Is an index needed for a primary key in SQLite?
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It does it for you.
INTEGER PRIMARY KEY columns aside, both UNIQUE and PRIMARY KEY
constraints are implemented by creating an index in the database (in
the same way as a "CREATE UNIQUE INDEX" statement would). Such an
index is used like any other index in the database to optimize
que...
Python idiom to return first item or None
...last option is almost exactly what I'm looking for: it's clear, it works, and it doesn't require me to define a new function. I'd say "exactly" if the break were somehow not needed, because the risk of omitting it is not insignificant. But this approach has the ring of truth.
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What is the use case of noop [:] in bash?
...ver'
done
It's traditional to use : when the shell syntax requires a command but you have nothing to do.
while keep_waiting; do
: # busy-wait
done
The : builtin dates all the way back to the Thompson shell, it was present in Unix v6. : was a label indicator for the Thompson shell's goto state...
APT command line interface-like yes/no input?
... there any short way to achieve what the APT ( Advanced Package Tool ) command line interface does in Python?
19 Answers
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What are the effects of exceptions on performance in Java?
Question: Is exception handling in Java actually slow?
18 Answers
18
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or (HTML5)
W3Schools.com and I'm pretty sure I remember seeing W3C.org state that <menu> should be used for Toolbar menus and listing form control commands.
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Does order of where clauses matter in SQL?
...irstName , none of these columns are indexed.
LastName is more unique, and FirstName is less unique.
6 Answers
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Mod in Java produces negative numbers [duplicate]
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The problem here is that in Python the % operator returns the modulus and in Java it returns the remainder. These functions give the same values for positive arguments, but the modulus always returns positive results for negative input, whereas the remainder may give negative results. There's...
System.Timers.Timer vs System.Threading.Timer
I have been checking out some of the possible timers lately, and System.Threading.Timer and System.Timers.Timer are the ones that look needful to me (since they support thread pooling).
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