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ALTER TABLE to add a composite primary key
...t it after you recreate the primary key.
Also, when using composite keys, order is important.
These
1) ALTER TABLE provider ADD PRIMARY KEY(person,place,thing);
and
2) ALTER TABLE provider ADD PRIMARY KEY(person,thing,place);
are not the the same thing.
They both enforce uniqueness on that set ...
Type-juggling and (strict) greater/lesser-than comparisons in PHP
...tors deviate from the computer-scientific definitions in several ways:
In order to constitute an equivalence relation == has to be reflexive, symmetric and transitive:
PHP's == operator is not reflexive, i.e. $a == $a is not always true:
var_dump(NAN == NAN); // bool(false)
Note: The fact that...
How SID is different from Service name in Oracle tnsnames.ora
...ich this instance connects. You can
specify multiple services names in
order to distinguish among different
uses of the same database. For
example:
SERVICE_NAMES = sales.acme.com,
widgetsales.acme.com
You can also use service names to
identify a single service that is
availab...
Append a dictionary to a dictionary [duplicate]
...itional copy merging both, you create a lookup chain that searches both in order. Because it doesn't duplicate the mappings it wraps ChainMap uses very little memory, and sees later modifications to any sub-mapping. Because order matters you can also use the chain to layer defaults (i.e. user prefs ...
Enter triggers button click
...is a <input type="submit"> . The buttons appear on the page in that order. If I'm in a text field anywhere in the form and press <Enter> , the button element's click event is triggered. I assume that's because the button element sits first.
...
Global variables in Java
...ggest your rename your class from Global to something else (TestClass?) in order not to give people the impression that there is such a thing as a Global Java keyword. Better safe than sorry :)
– Nicolas Rinaudo
Jul 25 '13 at 13:36
...
How to make ruler always be shown in Sublime text 2?
...ces -> Settings-User and change
"rulers": [],
to
"rulers": [80],
in order to display one ruler at column 80.
Now for the rub, it seems that one must use a monospaced font in order to display rulers so you'll also need to change
"font_face": "",
to
"font_face": "Monospace",
or any other m...
Multiplication on command line terminal
...ld have shown non-integer operands instead of only a non-integer result in order to accurately counter the assertion. Never fear, echo '4 k 50.5 7 / p' | dc works (output: 7.2142).
– Paused until further notice.
Jun 15 '12 at 1:54
...
How to add 'ON DELETE CASCADE' in ALTER TABLE statement
... where constraint_name = theCons and owner = theOwner
order by position;
firstCol BOOLEAN := TRUE;
begin
-- For each constraint
FOR cons IN (select * from user_constraints
where delete_rule = 'NO ACTION'
and constraint_name not l...
How to retrieve the current value of an oracle sequence without increment it?
...t updates to the record, you need to have a way to extract that value.
In order to make sure you get the right one, you might want to wrap the INSERT and RonK's query in a transaction.
RonK's Query:
select MY_SEQ_NAME.currval from DUAL;
In the above scenario, RonK's caveat does not apply since ...