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Python: Select subset from list based on index set
...ecause this will be very familiar syntax to users of R, where this kind of selection is very powerful, especially when nested and/or multidimensional.
– Thomas Browne
May 25 '14 at 21:11
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postgresql COUNT(DISTINCT …) very slow
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You can use this:
SELECT COUNT(*) FROM (SELECT DISTINCT column_name FROM table_name) AS temp;
This is much faster than:
COUNT(DISTINCT column_name)
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How to select an element by classname using jqLite?
...y, and as-noted by @kevin-b:
// find('#id')
angular.element(document.querySelector('#id'))
//find('.classname'), assumes you already have the starting elem to search from
angular.element(elem.querySelector('.classname'))
Note: If you're looking to do this from your controllers you may want to ha...
How do I add a foreign key to an existing SQLite table?
...n step 8 below. One way to
do this is to run a query like the following: SELECT type, sql FROM
sqlite_master WHERE tbl_name='X'.
Use CREATE TABLE to construct a new table "new_X" that is in the
desired revised format of table X. Make sure that the name "new_X"
does not collide with any exi...
In Eclipse, what can cause Package Explorer “red-x” error-icon when all Java sources compile without
...ers e.g __duplicatefile.java . To fix this, rightclick on the project and select : Show In > Navigator . Then delete the duplicate files with underscore and build your project.
– GraSim
May 29 '15 at 10:28
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Is there a python equivalent of Ruby's 'rvm'?
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Optionally, if you're using Macports you can use python_select.
Install python_select with:
$ sudo port install python_select
Assuming python 2.6 and 2.5 have bee installed via Macports you can switch pythons like so:
$ sudo python_select python25
=> Selecting version "pyth...
Cleanest way to build an SQL string in Java
...uild an SQL string to do database manipulation (updates, deletes, inserts, selects, that sort of thing) - instead of the awful string concat method using millions of "+"'s and quotes which is unreadable at best - there must be a better way.
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Code formatting shortcuts in Android Studio for Operation Systems
...System Settings → Keyboard → Shortcuts tab → System → Lock Screen.
Select the row New Accelerator..., then press any special key with the Alpha key (e.g. Shift + L). You should've successfully changed the keyboard shortcut.
Check if the keyboard shortcut now works in Android Studio.
Altern...
CSS last-child selector: select last-element of specific class, not last child inside of parent?
I want to select #com19 ?
6 Answers
6
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App Inventor 2 SQLite 拓展：超流行兼容主流SQL语法的迷你本地数据库引擎...
...原始调用中指定的标签以及新行或更新行的行 ID。
AfterSelect(tag,rowCount,rows)
此事件在异步 Select 调用后触发。
提供原始调用中指定的标签、返回的行数以及结果行数据。
AfterUpdate(tag,rowCount)
此事件在异步 Update 调用后触发。...