大约有 44,000 项符合查询结果（耗时：0.0464秒） [XML]
Adding 'serial' to existing column in Postgres
...int, b text);
CREATE TABLE bar (a serial, b text);
INSERT INTO foo (a, b) SELECT i, 'foo ' || i::text FROM generate_series(1, 5) i;
INSERT INTO bar (b) SELECT 'bar ' || i::text FROM generate_series(1, 5) i;
-- blocks of commands to turn foo into bar
CREATE SEQUENCE foo_a_seq;
ALTER TABLE foo ALTER...
Using Regex to generate Strings rather than match them
...
I am not sure Xeger is that good. It cannot handle character classes. It fails to recognize a simple [\w]. A look at the last line of their wiki tells us that.
– John Red
Feb 13 '17 at 12:38
...
Select where count of one field is greater than one
...clause, for aggregate result comparison.
Taking the query at face value:
SELECT *
FROM db.table
HAVING COUNT(someField) > 1
Ideally, there should be a GROUP BY defined for proper valuation in the HAVING clause, but MySQL does allow hidden columns from the GROUP BY...
Is this in preparati...
Ruby on Rails form_for select field with class
I am beating my head against the wall on this one. I want to make a simple select tag using the f.select tag but nothing I do works. I put an example below:
...
jquery change class name
... process.
Let's assume that your "External DOM Object" is an input, like a select:
Let's start with this HTML:
<body>
<div>
<select id="test">
<option>Bob</option>
<option>Sam</option>
<option>Sue</option>
<opti...
In SQL, how can you “group by” in ranges?
...version.
Here are the correct versions of both of them on SQL Server 2000.
select t.range as [score range], count(*) as [number of occurences]
from (
select case
when score between 0 and 9 then ' 0- 9'
when score between 10 and 19 then '10-19'
else '20-99' end as range
from scores)...
Uniq by object attribute in Ruby
What's the most elegant way to select out objects in an array that are unique with respect to one or more attributes?
14 An...
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...
querySelector search immediate children
...
Though it's not a full answer, you should keep an eye on the W3C Selector API v.2 which is already available in most browser, both desktop and mobile, except IE (Edge seems to support): see full support list.
function(elem) {
return elem.querySelectorAll(':scope > someselector');
};
...
Array versus List: When to use which?
...rable is not suitable.
For example,
var str = "This is a string";
var strChars = str.ToCharArray(); // returns array
It is clear that modification of "strChars" will not mutate the original "str" object, irrespective implementation-level knowledge of "str"'s underlying type.
But suppose that
...