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Using backticks around field names
...backticks, I would assume it lets you get away with ridiculous stuff like
SELECT `id`, `my name`, `another field` , `field,with,comma`
Which does of course generate badly named tables.
If you're just being concise I don't see a problem with it,
you'll note if you run your query as such
EXPLA...
Random record in ActiveRecord
...he first, all after are still sorted by id). If you need multiple randomly selected records you must use this approach multiple times or use the random order method provided by your database, i.e. Thing.order("RANDOM()").limit(100) for 100 randomly selected entries. (Be aware that it's RANDOM() in P...
MySQL date format DD/MM/YYYY select query?
...ably just want to format the output date? then this is what you are after
SELECT *, DATE_FORMAT(date,'%d/%m/%Y') AS niceDate
FROM table
ORDER BY date DESC
LIMIT 0,14
Or do you actually want to sort by Day before Month before Year?
...
Return 0 if field is null in MySQL
...
Would that be IFNULL((SELECT SUM(uop.price * uop.qty) FROM uc_order_products uop WHERE uo.order_id = uop.order_id) AS products_subtotal, 0)?
– Kevin
Oct 22 '10 at 13:46
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Select mySQL based only on month and year
...
SELECT * FROM projects WHERE YEAR(Date) = 2011 AND MONTH(Date) = 5
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How to merge 2 List and removing duplicate values from it in C#
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Have you had a look at Enumerable.Union
This method excludes duplicates from the return set. This is different
behavior to the Concat
method, which returns all the elements
in the input sequences including
duplicates.
List<int> list1 = new List<int...
Why there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT clause?
...pdated) values(null, null);
Query OK, 1 row affected (0.06 sec)
mysql> select * from t5;
+----+---------------------+---------------------+
| id | stamp_created | stamp_updated |
+----+---------------------+---------------------+
| 2 | 2009-04-30 09:44:35 | 2009-04-30 09:44:35 |
+...
linux下iptables配置详解 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...tables -Z -t nat
2,添加规则
添加基本的NAT地址转换,(关于如何配置NAT可以看我的另一篇文章),
添加规则,我们只添加DROP链.因为默认链全是ACCEPT.
防止外网用内网IP欺骗
[root@tp sysconfig]# iptables -t nat -A PREROUTING -i eth0 -s 10.0.0.0/8 -j DRO...
When should I use a composite index?
...nefit a query that uses those fields for joining, filtering, and sometimes selecting. It will also benefit queries that use left-most subsets of columns in that composite. So the above index will also satisfy queries that need
index( column_A, column_B, column_C )
index( column_A, column_B )
index(...
Multi-statement Table Valued Function vs Inline Table Valued Function
...statement table valued function (MSTVF) even if they both simply execute a SELECT statement. SQL Server will treat an ITVF somewhat like a VIEW in that it will calculate an execution plan using the latest statistics on the tables in question. A MSTVF is equivalent to stuffing the entire contents of ...