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What is the difference between HAVING and WHERE in SQL?
...his code:
select City, CNT=Count(1)
From Address
Where State = 'MA'
Group By City
Gives you a table of all cities in MA and the number of addresses in each city.
This code:
select City, CNT=Count(1)
From Address
Where State = 'MA'
Group By City
Having Count(1)>5
Gives you a table of cities...
How to define a custom ORDER BY order in mySQL
...ndy function called FIELD() which is excellent for tasks like this.
ORDER BY FIELD(Language,'ENU','JPN','DAN'), ID
Note however, that
It makes your SQL less portable, as other DBMSs might not have such function
When your list of languages (or other values to sort by) gets much longer, it's bette...
Clear text from textarea with selenium
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driver.find_element_by_id('foo').clear()
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Grouping functions (tapply, by, aggregate) and the *apply family
...er answers) that much of the functionality of the *apply family is covered by the extremely popular plyr package, the base functions remain useful and worth knowing.
This answer is intended to act as a sort of signpost for new useRs to help direct them to the correct *apply function for their parti...
PostgreSQL: Modify OWNER on all tables simultaneously in PostgreSQL
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See the recent answer by @trygvis. Simplest answer by far: REASSIGN OWNED BY old_role [, ...] TO new_role
– David
Dec 4 '12 at 23:39
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Drop all the tables, stored procedures, triggers, constraints and all the dependencies in one sql st
Is there any way in which I can clean a database in SQl Server 2005 by dropping all the tables and deleting stored procedures, triggers, constraints and all the dependencies in one SQL statement?
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Are there best practices for (Java) package organization? [closed]
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I agree package by feature makes the most sense. I heard a great analogy once related to a company office structure. In a layered approach, each of the individuals per level in a company would sit with each other i.e. Executives, managers, a...
Group by & count function in sqlalchemy
I want a "group by and count" command in sqlalchemy. How can I do this?
3 Answers
3
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How to pass parameters correctly?
...cations to that object will be visible to the caller, then you should pass by lvalue reference:
void foo(my_class& obj)
{
// Modify obj here...
}
If your function does not need to modify the original object, and does not need to create a copy of it (in other words, it only needs to observ...
MySQL select 10 random rows from 600K rows fast
...ps, to non-uniform with gaps.
http://jan.kneschke.de/projects/mysql/order-by-rand/
For most general case, here is how you do it:
SELECT name
FROM random AS r1 JOIN
(SELECT CEIL(RAND() *
(SELECT MAX(id)
FROM random)) AS id)
AS r2
WHERE...