大约有 37,000 项符合查询结果（耗时：0.0438秒） [XML]
How to get record created today by rails activerecord?
...ion suggested in the accepted answer can cause performance issues when the table size grows.
Typically, if you perform lookups based on created_at column, add an index on the table in your migration file.
add_index :posts, :created_at
Now, to lookup records created today:
Rails 3/4
Post.where...
How can I see the SQL generated by Sequelize.js?
...I need to check if they are correct. In particular, I am interested in the table creation commands.
4 Answers
...
What are the use cases of Graph-based Databases (http://neo4j.org/)? [closed]
...nto the current blub architecture, use a graph database, or CouchDB, or BigTable, or whatever fits your app and you think is cool. It might give you an advantage, and its fun to try new things.
Whatever you chose, try not to build the database engine yourself unless you really like building databas...
Setting element of array from Twig
...That will work only when keys are strings
What I did is recreate another table ( temp) from the initial table (t) and make the keys a string , for example :
{% for key , value in t%}
{% set temp= temp|merge({(key~'_'):value}) %}
{% endfor %}
t keys : 0 , 1 , 2 ..
temp keys : 0_, 1_ , 2_ ......
When to use nil, blank, empty? [duplicate]
...
Here I made this useful table with all the cases
share
|
improve this answer
|
follow
|
...
SQL Server equivalent to Oracle's CREATE OR REPLACE VIEW
...ISTS' to check if the view exists and drop if it does.
IF EXISTS (SELECT TABLE_NAME FROM INFORMATION_SCHEMA.VIEWS
WHERE TABLE_NAME = 'MyView')
DROP VIEW MyView
GO
CREATE VIEW MyView
AS
....
GO
share
...
Is the NOLOCK (Sql Server hint) bad practice?
...dated at the same time another process may be selecting data from the same table. If this happens a lot then there's a high probability of deadlocks unless you use a database mode such as READ COMMITED SNAPSHOT.
I have since changed my perspective on the use of NOLOCK after witnessing how it can i...
Why can't I use switch statement on a String?
...nse, they are used as an index (after subtracting the lowest value) into a table of instruction pointers—the tableswitch instruction.
If the constants are sparse, a binary search for the correct case is performed—the lookupswitch instruction.
In de-sugaring a switch on String objects, both i...
How to grant remote access permissions to mysql server for user?
...FIED BY 'YOUR_PASS'
WITH GRANT OPTION;
FLUSH PRIVILEGES;
*.* = DB.TABLE you can restrict user to specific database and specific table.
'root'@'%' you can change root with any user you created and % is to allow all IP. You can restrict it by changing %.168.1.1 etc too.
If that doesn't ...
How to extract year and month from date in PostgreSQL without using to_char() function?
I want to select sql:
SELECT "year-month" from table group by "year-month" AND order by date , where
year-month - format for date "1978-01","1923-12".
select to_char of couse work , but not "right" order:
...