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Postgresql aggregate array
...
Use array_agg: http://www.sqlfiddle.com/#!1/5099e/1
SELECT s.name, array_agg(g.Mark) as marks
FROM student s
LEFT JOIN Grade g ON g.Student_id = s.Id
GROUP BY s.Id
By the way, if you are using Postgres 9.1, you don't need to repeat the columns on SELECT to GROUP BY,...
Is it possible to center text in select box?
...you could style the dropdown:
https://www.filamentgroup.com/lab/jquery-ui-selectmenu-an-aria-accessible-plugin-for-styling-a-html-select.html
This plugin hides the select element, and creates span elements etc on the fly to display a custom drop down list style. I'm quite confident you'd be able t...
How to request a random row in SQL?
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See this post: SQL to Select a random row from a database table. It goes through methods for doing this in MySQL, PostgreSQL, Microsoft SQL Server, IBM DB2 and Oracle (the following is copied from that link):
Select a random row with MySQL:
SELE...
Table name as variable
...mpare data between the same tables of different databases:
static query:
SELECT * FROM [DB_ONE].[dbo].[ACTY]
EXCEPT
SELECT * FROM [DB_TWO].[dbo].[ACTY]
since I want easily change tha name of table and schema I have created this dynamic query:
declare @schema varchar(50)
declare @table varchar(5...
What is the fastest integer division supporting division by zero no matter what the result is?
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Awesome. Can be made constexpr and avoid needless type casts like this: template<typename T, typename U> constexpr auto fdiv( T t, U u ) -> decltype(t/(u+!u)) { return t/(u+!u); } And if you want 255, (lhs)/(rhs+!rhs) & -!rhs
– Yakk - Adam Nevr...
SQL Server Profiler - How to filter trace to only display events from one database?
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Under Trace properties > Events Selection tab > select show all columns. Now under column filters, you should see the database name. Enter the database name for the Like section and you should see traces only for that database.
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Swapping column values in MySQL
...rows affected (0.08 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> SELECT * FROM swaptest;
+------+------+
| X | Y |
+------+------+
| 1 | 2 |
| 3 | 4 |
| -5 | -8 |
| -13 | 27 |
+------+------+
4 rows in set (0.00 sec)
mysql>
Here is the swap being performed
m...
MFC CListCtrl使用方法详解 - C/C++ - 清泛网 - 专注C/C++及内核技术
...DWORD dwStyle = m_list.GetExtendedStyle();
dwStyle |= LVS_EX_FULLROWSELECT;//选中某行使整行高亮（只适用与report风格的listctrl）
dwStyle |= LVS_EX_GRIDLINES;//网格线（只适用与report风格的listctrl）
dwStyle |= LVS_EX_CHECKBOXES;//item前生成checkbox...
How do I configure a Python interpreter in IntelliJ IDEA with the PyCharm plugin?
... to File > Project Structure.
Under the Project menu for Project SDK, select "New" and
Select "Python SDK", then select "Local".
Provided you have a Python SDK installed, the flow should be natural from there - navigate to the location your Python installation lives.
...
When and why would you seal a class?
... think this post has some good point, the specific case was when trying to cast a non-sealed class to any random interface, compiler doesn't throw error; but when sealed is used the compiler throws error that it can't convert. Sealed class brings additional code access security.
https://www.codeproj...