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Unioning two tables with different number of columns
...in column orders. this example below produces an error:
create table test1_1790 (
col_a varchar2(30),
col_b number,
col_c date);
create table test2_1790 (
col_a varchar2(30),
col_c date,
col_b number);
select * from test1_1790
union all
select * from test2_1790;
ORA-01790: expression must have ...
What is the difference between ManualResetEvent and AutoResetEvent in .NET?
...ass ManualResetEventSample
{
private readonly ManualResetEvent _manualReset = new ManualResetEvent(false);
public void RunAll()
{
new Thread(Worker1).Start();
new Thread(Worker2).Start();
new Thread(Worker3).Start();
Consol...
How to organize a node app that uses sequelize?
...e is cached after the first execution. nodejs.org/api/modules.html#modules_caching
– Casey Flynn
Mar 29 '13 at 7:17
2
...
Hide the cursor of an UITextField
...irst, store the text field's selected text range to an instance variable.
_textFieldSelectedTextRange = textField.selectedTextRange;
textField.selectedTextRange = nil; // hides caret
Then, when you want to unhide the caret, simply set the text field's selected text range back to what it was origi...
Mapping over values in a python dictionary
...ch function; the easiest way to do this is to use a dict comprehension:
my_dictionary = {k: f(v) for k, v in my_dictionary.items()}
In python 2.7, use the .iteritems() method instead of .items() to save memory. The dict comprehension syntax wasn't introduced until python 2.7.
Note that there is ...
Remove by _id in MongoDB console
...
Very close. This will work:
db.test_users.deleteOne( {"_id": ObjectId("4d512b45cc9374271b02ec4f")});
i.e. you don't need a new for the ObjectId.
Also, note that in some drivers/tools, remove() is now deprecated and deleteOne or deleteMany should be used ins...
Only read selected columns
...,Apr,May,Jun from file",
sep = "\t")
3) With the read_*-functions from the readr-package:
library(readr)
dat <- read_table("data.txt",
col_types = cols_only(Year = 'i', Jan = 'i', Feb = 'i', Mar = 'i',
Apr = 'i', May...
How to determine whether a given Linux is 32 bit or 64 bit?
...
Try uname -m. Which is short of uname --machine and it outputs:
x86_64 ==> 64-bit kernel
i686 ==> 32-bit kernel
Otherwise, not for the Linux kernel, but for the CPU, you type:
cat /proc/cpuinfo
or:
grep flags /proc/cpuinfo
Under "flags" parameter, you will see various value...
How to make MySQL handle UTF-8 properly
... answer - You should almost always be using the utf8mb4 charset and utf8mb4_unicode_ci collation.
To alter database:
ALTER DATABASE dbname CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
See:
Aaron's comment on this answer How to make MySQL handle UTF-8 properly
What's the difference betwee...
Why can I access TypeScript private members when I shouldn't be able to?
...
Doesn't typescript do this ALL the time by setting var _this for use in scoped functions? Why would you have qualms doing it at the class scope?
– DrSammyD
Mar 24 '16 at 17:22
...