大约有 40,000 项符合查询结果（耗时：0.0441秒） [XML]
What is the right way to override a setter method in Ruby on Rails?
...iginal Answer
If you want to override the setter methods for columns of a table while accessing through models, this is the way to do it.
class Model < ActiveRecord::Base
attr_accessible :attribute_name
def attribute_name=(value)
# custom actions
###
write_attribute(:attribute_...
What is PostgreSQL explain telling me exactly?
...efore it starts writing rows: a sequential scan reads the first row of the table and emits it. The LIMIT reads its first row and then emits it.
When would a component need to do a lot of processing before it can start to output any rows? There are a lot of possible reasons, but let's look at one cl...
How to fix the datetime2 out-of-range conversion error using DbContext and SetInitializer?
...l DateTime Start { get; set; } to datetime2 in corresponding column in the table. Because by default EF will map it to datetime.
This can be done by fluent API or data annotation.
Fluent API
In DbContext class overide OnModelCreating and configure property Start (for explanation reasons it's a ...
SQL Server - When to use Clustered vs non-Clustered Index?
...ing: please very carefully pick your clustered index! Every "regular" data table ought to have a clustered index, since having a clustered index does indeed speed up a lot of operations - yes, speed up, even inserts and deletes! But only if you pick a good clustered index.
It's the most replicated ...
Do while loop in SQL Server 2008
...)
DECLARE Iterator CURSOR FORWARD_ONLY FOR
SELECT Id, Title FROM dbo.SourceTable
OPEN Iterator
WHILE 1=1 BEGIN
FETCH NEXT FROM @InputTable INTO @Id, @Title
IF @@FETCH_STATUS < 0 BREAK
PRINT 'Do something with ' + @Title
END
CLOSE Iterator
DEALLOCATE Iterator
Unfortunately, T-SQL doe...
Convert timestamp to date in MySQL query
...
Convert timestamp to date in MYSQL
Make the table with an integer timestamp:
mysql> create table foo(id INT, mytimestamp INT(11));
Query OK, 0 rows affected (0.02 sec)
Insert some values
mysql> insert into foo values(1, 1381262848);
Query OK, 1 row affected (...
How do you create a Distinct query in HQL
...esults. They were just distinct based on a primary key combination on the table.
So in the DaoImpl I added an one line change and ended up getting the "distinct" return I wanted. An example would be instead of seeing 00 four times I now just see it once. Here is the code I added to the DaoImpl:
...
Using :after to clear floating elements
...s well:
.clearfix:before,
.clearfix:after {
content: "";
display: table;
}
.clearfix:after {
clear: both;
}
/* IE 6 & 7 */
.clearfix {
zoom: 1;
}
Give the class clearfix to the parent element, for example your ul element.
Sources here and here.
...
What is the difference between a HashMap and a TreeMap? [duplicate]
...y works with Comparable objects, HashMap only works with objects with a suitable hashCode() implementation.
– Thilo
Mar 15 '10 at 1:29
11
...
MySQL Query - Records between Today and Last 30 Days
... the WHERE clause:
SELECT DATE_FORMAT(create_date, '%m/%d/%Y')
FROM mytable
WHERE create_date BETWEEN CURDATE() - INTERVAL 30 DAY AND CURDATE()
Also note that CURDATE() returns only the DATE portion of the date, so if you store create_date as a DATETIME with the time portion filled, this qu...